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Latency Analyzer (LANZ)

Arista Networks’ Latency Analyzer (LANZ) is a family of EOS features that provide enhanced visibility into network dynamics, particularly in areas related to the delay packets experience through the network. The LANZ feature is available on the FM6000, Arad, Trident II, Trident 3, Jericho, Tomahawk and XP80 switch platforms.

This section describes the purpose, behavior, and configuration of LANZ features. Topics covered by this section include:

Introduction to LANZ

LANZ tracks interface congestion and queuing latency with real-time reporting. With LANZ application layer event export, external applications can predict impending congestion and latency. This enables the application layer to make traffic routing decisions with visibility into the network layer.

With LANZ, network operations teams and administrators have near real-time visibility into the network, enabling early detection of microbursts. LANZ continually monitors congestion, allowing for rapid detection of congestion and sending of application layer messages.

LANZ Overview

LANZ monitors output queue lengths to provide congestion information for individual interfaces. This allows for more detailed analysis of congestion events, and allows identification of potential latency problems before they arise. On some platforms, LANZ also monitors global buffer usage.

Output queues for each port are monitored, and information about queue congestion events can be accessed in the form of system log messages, reports, or streaming.

LANZ Monitoring Mechanism

LANZ provides congestion data by continuously monitoring each port’s output queue lengths. When the length of an output queue exceeds the upper threshold for that port, LANZ generates an over-threshold event.

Notifying and Polling Modes

Notifying Mode

In Notifying Mode (available on all platforms), LANZ monitors congestions on all queues and generates Start, Update, and End events every five seconds or at user-configured intervals.

  • Start     event is generated when any queue on an interface exceeds the upper threshold.
  • Update     events are generated periodically while the congested queue remains above the lower threshold. The interval at which Update events are generated is configured using the queue-monitor length update-interval command.
  • End     event is generated when the congested queue drops below the lower threshold.
Polling Mode

Polling Mode is available only on Arad and Jericho switches. On these switches, LANZ can be configured to use Notifying Mode, but it operates in Polling Mode by default. In Polling Mode, LANZ polls the most congested queue in each ASIC and continues to report an over-threshold state every 800 microseconds until all queue lengths for the port pass below the lower threshold.

LANZ Logging

Over-threshold events generated by LANZ can be logged as system log messages. Log messages are generated for events on all ports, at a maximum rate of one message per second per interface. The interval between messages can be configured globally.

Log messages indicate the time of the event, the interface affected, the threshold set for that interface, and the actual number of entries in the port’s queue.

LANZ Reporting

Detailed LANZ data can be viewed through the CLI or exported as a CSV-formatted report.

A circular FIFO event buffer is dynamically shared by all interfaces. When an interface begins generating LANZ over-threshold events it can fill all available buffer space. However, each interface is guaranteed sufficient resources for a minimum of 500 entries.

LANZ Streaming

On some platforms, external client applications can also receive congestion event information as a data stream. The switch can stream LANZ data to up to 100 clients via TCP through port 50001.

Streamed data is in Google protocol buffer format, and includes both over-threshold events and LANZ configuration information.

Platforms

The LANZ feature is available on the FM6000, Arad, Trident II, Trident 3, Jericho and Tomahawk switch platforms. To determine the switch platform from the CLI, enter show platform ? at the prompt.

Settings and capabilities differ slightly between the platforms:

  • Arad chips measure threshold values in bytes; all others measure threshold values in segments:

    • FM6000     480-byte segments
    • Trident II and Tomahawk     208-byte segments
    • Trident 3     256-byte segments
  • FM6000, Trident II, Trident 3, and Tomahawk chips allow configuration of both upper and lower threshold values.
  • FM6000, Arad, Jericho, Trident II, Trident 3, and Tomahawk chips support LANZ data streaming.
  • Only FM6000 chips support global buffer monitoring.
  • While the FM6000, Trident II, Trident 3, Jericho and Tomahawk chips can monitor congestion events for all queues, the Arad chips only monitor the most congested queues.
  • Polling Mode is available on Arad and Jericho platforms.
  • LANZ is available on CPU ports on Arad, Jericho, Trident II and Tomahawk platforms.
  • LANZ is available on fabric ports on Trident, Trident II, Trident 3, and Tomahawk platforms.

Configuring LANZ

LANZ is disabled by default and must be enabled to function. Upper and lower queue-length thresholds can be defined for individual interfaces.

These sections describe the basic LANZ configuration steps:

Enabling and Disabling LANZ

LANZ is enabled by default on Sand platform switches (those with Arad, Jericho, or Qumran chipsets), allowing the switch to collect and display latency information. LANZ is disabled by default on all other switches. If LANZ is disabled, the queue-monitor length (global configuration mode) command enables LANZ with the current settings, or with the default settings if none have been configured.

When LANZ is enabled, the switch monitors queue lengths on all front-panel ports, and on CPU and fabric ports on selected platforms. Queue length data is available in the following forms:

To disable LANZ globally, enter the no queue-monitor length command in global configuration mode. Disabling LANZ globally also discards LANZ log data, but retains settings. To disable LANZ on an individual interface, enter the no queue-monitor length command in interface Ethernet configuration mode.

Examples

  • This command enables LANZ on the switch.

    switch(config)#queue-monitor length
    switch(config)#
  • This command disables LANZ on the switch.

    switch(config)#no queue-monitor length
    switch(config)#
  • These commands disable LANZ on Ethernet interface 7.

    switch(config)#interface ethernet 7
    switch(config-if-Et7)#no queue-monitor length
    switch(config-if-Et7)#

Specifying the LANZ Mode on Jericho and Arad Switches

On Jericho and Arad switches, LANZ operates by default in Polling Mode, which provides congestion data for the most congested queue per ASIC. They also support Notifying Mode (the LANZ mode used on all other switches), which generates Start, Update, and End events for all queues.

Notifying Mode is enabled using the queue-monitor length notifying command.

Examples

  • This command enables Notifying Mode on a Jericho or Arad switch.

     switch(config)#queue-monitor length notifying 
  • This command disables Notifying Mode on a Jericho or Arad switch, returning LANZ to the default Polling Mode.

    switch(config)#no queue-monitor length notifying 

Configuring LANZ Congestion Thresholds

When LANZ is enabled on the switch, it generates over-threshold events when queue lengths on any monitored interface exceed the upper threshold value and continues generating them until all the queue lengths on that interface drop back below the lower threshold.

Setting the Congestion Update Interval

The queue-monitor length update-interval command specifies the frequency with which congestion information is updated in microseconds.

  • This command sets the time between congestion updates to 10 seconds.

    switch(config)# queue-monitor length update-interval 10000000
    switch(config)#
    
  • This command resets the time between congestion updates to its default value of 5 seconds.

    switch(config)# default queue-monitor length update-interval
    switch(config)#
    

Congestion Thresholds on FM6000, Trident II, Trident 3, and Tomahawk Switches

Queue lengths are measured in 480-byte segments on FM6000 switches, in 208-byte segments on Trident II and Tomahawk switches, and in 256-byte segments on Trident 3 switches. The default threshold values are 512 segments and 256 segments. To change the threshold values for a specific interface, use the queue-monitor length thresholds command.

FM6000 switches can also monitor global buffer usage. Global buffers are measured in 160-byte segments; the default threshold values are 10940 segments and 4376 segments. To enable global buffer monitoring, use the queue-monitor length global-buffer command. To change the threshold values for global buffer usage monitoring on the switch, use the queue-monitor length global-buffer thresholds command.

Examples
  • These commands set the upper and lower queue-length thresholds on Ethernet interface 5 to 300 segments and 200 segments.

    switch(config)#interface ethernet 5
    switch(config-if-Et5)#queue-monitor length thresholds 300 200
    switch(config-if-Et5)#
    
  • These commands enable global buffer monitoring on the switch and set the upper and lower thresholds to 9000 segments and 4000 segments.

    switch(config)# queue-monitor length global-buffer
    switch(config)#queue-monitor length global-buffer thresholds 9000 4000
    switch(config)#
    

Congestion Thresholds on Arad Switches

Queue lengths are measured in bytes. The top threshold value can be between 2 and 52428800 bytes (the default value is 52428800 bytes). To change the upper threshold value for a specific interface, use the queue-monitor length threshold (Arad/Jericho) command.

Example
These commands set the upper queue-length threshold on Ethernet interface 5 to 2614400 bytes.
switch(config)#interface ethernet 5
switch(config-if-Et5)#queue-monitor length thresholds 2614400
switch(config-if-Et5)#

CPU Port Congestion Thresholds

CPU port queue lengths are also monitored on selected platforms. All CPU ports share common threshold values, which are configured using the queue-monitor length cpu thresholds command. Individual CPU port congestion thresholds cannot be separately configured.

Examples
  • This command sets the upper queue-length threshold for congestion monitoring on all CPU ports to 1000 segments and the lower limit to 300 segments.

    switch(config)# queue-monitor length cpu thresholds 1000 300
    switch(config)#
    
  • This command resets the queue-length thresholds for CPU port congestion to the default values of 512 and 256.

    switch(config)# default queue-monitor length cpu thresholds
    switch(config)#
    

Fabric Port Congestion Thresholds

Fabric port queue lengths are also monitored on selected platforms. All fabric ports share common threshold values, which are configured using the queue-monitor length fabric thresholds command. Individual fabric port congestion thresholds cannot be separately configured.

Examples
  • This command sets the upper queue-length threshold for congestion monitoring on all fabric ports to 1000 segments and the lower limit to 300 segments.

    switch(config)# queue-monitor length fabric thresholds 1000 300
    switch(config)#
    
  • This command resets the queue-length thresholds for fabric port congestion to the default values of 512 and 256.

    switch(config)# default queue-monitor length fabric thresholds
    switch(config)#
    

Setting LANZ Traffic Sampling

The switch can be configured to automatically send congested traffic to either the CPU or an Ethernet egress interface destination when a queue threshold is crossed by enabling LANZ mirroring through the command queue-monitor length mirror. The CPU or an egress interface mirror destination is then configured through the command queue-monitor length mirror destination. LANZ traffic sampling includes exporting congested traffic to a packet capture device or another tool for analysis, or directly to the switch CPU for inspection through the command tcpdump queue-monitor.

Examples

  • This command enables LANZ traffic sampling.

    switch(config)#queue-monitor length mirror
    switch(config)#
  • This command disables LANZ traffic sampling.

    switch(config)#no queue-monitor length mirror
    switch(config)#
  • This command configures LANZ traffic sampling for a CPU interface mirror destination.
    switch(config)#queue-monitor length mirror destination cpu
    switch(config)#
  • This command configures LANZ traffic sampling for an Ethernet interface mirror destination for ports 1 through 5.
    switch(config)#queue-monitor length mirror destination Ethernet 1-5
    switch(config)#
  • This command configures LANZ traffic sampling for an Ethernet interface mirror destination for ports 6, 10, and 12 through 14.
    switch(config)#queue-monitor length mirror destination Ethernet 6,10,12-14
    switch(config)#
  • This command inspects traffic on the switch.
    switch(config)#tcpdump queue-monitor
    tcpdump: WARNING: lanz: no IPv4 address assigned
    tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
    listening on lanz, link-type EN10MB (Ethernet), capture size 65535 bytes
    ...
    0 packets captured
    0 packets received by filter
    0 packets dropped by kernel
    switch(config)#

Logging LANZ Congestion Events

To generate syslog messages when queue lengths on an interface exceed its upper threshold, enable logging with the queue-monitor length log command. When logging is enabled, a log message is generated each time one or more queues on an interface exceed the upper threshold value for that interface (see queue-monitor length threshold (Arad/Jericho) or queue-monitor length thresholds). Once an interface is over threshold, additional messages are generated at a maximum rate of one per interval as long as the queue length remains above the lower threshold for that interface. No syslog message is generated when queue length drops back under threshold.

Queue length information is not included in log messages, but can be accessed by displaying LANZ data or exporting reports.

On FM6000 platforms, log messages can also be created whenever global buffer usage exceeds its upper threshold value (see queue-monitor length global-buffer thresholds). To enable global buffer monitoring, use the queue-monitor length global-buffer command. To log over-threshold events for the global buffer, use the queue-monitor length global-buffer log command.

Examples:
  • This command enables queue-length over-threshold logging with a minimum interval of 10 seconds between messages for a given interface.
    switch(config)#queue-monitor length log 10
  • This command disables queue-length over-threshold logging on the switch.
    switch(config)#queue-monitor length log 0
  • This is an example of a queue-length log message.
    Oct 27 12:48:22 switch QUEUE_MONITOR-6-LENGTH_OVER_THRESHOLD: Interface
    Ethernet6 queue length is over threshold of 512, current length is 1024.
    
  • This command enables global buffer over-threshold logging on the switch with a minimum interval of 60 seconds between messages.
    witch(config)#queue-monitor length global-buffer log 60

Viewing LANZ Data

LANZ status, and the data stored in the LANZ data buffer, can be viewed using the CLI. Output varies by switch platform, and can be limited to a specified number of records.

Viewing LANZ Data on Arad Platform Switches

When LANZ is enabled on an Arad platform switch, the show queue-monitor length command displays a report of recent over-threshold events for a range of interfaces or for all interfaces. By default, the command displays data for all interfaces, limited to the last 1000 records, with the most recent events listed first. To view a subset of the LANZ data, limited to a specified number of records, use the show queue-monitor length limit command.

Example

This command displays the last 100 records for Ethernet interfaces 6 through 8.

switch#show queue-monitor length ethernet 6-8 limit 100
Report generated at 2010-01-01 12:56:13

Time                        Interface   Queue length (segments, 1 to 512 bytes)
-------------------------------------------------------------------------------
0:00:07.43393 ago           Et6         1049
0:00:39.22856 ago           Et7         2039
1 day, 4:33:23.12345 ago    Et6         1077

To view the current LANZ configuration for the switch and for each interface, use the show queue-monitor length status command.

Example
This command displays LANZ configuration and status information.
switch(config)#show queue-monitor length status
Per-Interface Queue Length Monitoring
-------------------------------------
Queue length monitoring is enabled
Maximum queue length in bytes : 52428800
Port threshold in bytes:
Port High threshold
Et3/1 5242880
Et3/2 5242880
Et3/3 5242880
Et3/4 5242880
Et3/5 5242880

Viewing LANZ Data on FM6000, Trident II, Trident 3, and Tomahawk Platform Switches

When LANZ is enabled on an FM6000, Trident II, Trident 3, or Tomahawk platform switch, the show queue-monitor length command displays a report of recent over-threshold events for a range of interfaces or for all interfaces. By default, the command displays data for all interfaces, limited to the last 1000 records, with the most recent events listed first. To view a subset of the LANZ data, limited to a specified number of records, use the show queue-monitor length limit command.

Example
This command displays the last 100 records for Ethernet interfaces 6 through 8.
switch#show queue-monitor length ethernet 6-8 limit 100
Report generated at 2010-01-01 12:56:13

Time                        Interface   Queue length (segments, 1 to 512 bytes)
-------------------------------------------------------------------------------
0:00:07.43393 ago           Et6         1049
0:00:39.22856 ago           Et7         2039
1 day, 4:33:23.12345 ago    Et6         1077

To view the current LANZ configuration for the switch and for each interface, use the show queue-monitor length status command.

Example
This command displays LANZ configuration and status information.
switch(config)# show queue-monitor length status
queue-monitor length enabled
Global Buffer Monitoring
------------------------
Global buffer monitoring is enabled
Segment size in bytes : 160
Total buffers in segments : 36864
High threshold : 10940
Low threshold :4376


Per-Interface Queue Length Monitoring
-------------------------------------
Queue length monitoring is enabled
Segment size in bytes : 480
Maximum queue length in segments :3647
Port thresholds in segments:
Port High thresholdLow threshold
Et1 512256
Et2 512256
Et3 512256
Et4 512256
Et5 512256

To view all available LANZ records, use the show queue-monitor length all command.

Example
This command displays all available LANZ records.
switch> show queue-monitor length all

Report generated at 2013-04-01 13:23:13
E-End, U-Update, S-Start, TC-Traffic Class
GH-High, GU-Update, GL-Low
Segment size for E, U and S congestion records is 480 bytes
Segment size for GL, GU and GH congestion records is 160 bytes
* Max queue length during period of congestion
+ Period of congestion exceeded counter
-------------------------------------------------------------------------------
-
TypeTime IntfCongestion Queue Time of Max
 (TC)duration lengthQueue length
 (usecs)(segments)relative to
congestion
start
(usecs)
-------------------------------------------------------------------------------
-
E0:00:00.07567 ago Et22(7) >=71 mins20* 30us
GU 0:00:00.15325 ago N/A N/A5695N/A 
U0:00:00.19859 ago Et4(1)N/A5693N/A 
GU 0:00:00.95330 ago N/A N/A5696N/A 
U0:00:00.99859 ago Et4(1)N/A5695N/A 
E0:00:01.28821 ago Et44(1) 9672us 2502* 7294us
S0:00:01.17591 ago Et22(7) N/A26N/A
U0:00:03.08248 ago Et44(1) N/A50N/A
S12days,8:56:44.07567 agoEt44(1) N/A20N/A
switch>

On the FM6000, Trident II, Trident 3, and Tomahawk platforms, information is also available for the number of dropped packets (see show queue-monitor length drops) and transmission latency (see show queue-monitor length tx-latency); global buffer usage can also be viewed on FM6000 platforms (see show queue-monitor length global-buffer).

Streaming LANZ Data

To support analysis of latency conditions, the switch can be configured to stream LANZ congestion and configuration data. The switch streams LANZ data via TCP in Google protocol buffer format through port 50001 and through the management interface.

You must create a client application to receive the streaming data. By default, the switch will accept up to 10 client connections for streaming LANZ data. This limit can be configured up to a maximum of 100. Maximum connections can be configured when LANZ is disabled.

Enabling and Disabling LANZ Data Streaming

LANZ data streaming is disabled by default. To enable streaming, issue the no show queue-monitor streaming clients command in queue-monitor streaming configuration mode. To disable streaming, use the show queue-monitor streaming clients command.

When streaming is disabled, a message is sent to any connected clients and the connections are closed.

To ensure client access to LANZ data, add a rule to any relevant ACL permitting traffic destined for the LANZ port (50001) before initiating a client connection for streaming from a remote host. A static rule (sequence number 130) in the default control plane ACL permits LANZ traffic, but a similar rule must be added to any user-created ACL.

Examples
  • These commands enable the streaming of LANZ data from the switch.

    switch(config)#queue-monitor streaming
    switch(config-qm-streaming)#no shutdown
    switch(config-qm-streaming)#
    
  • These commands disable LANZ data streaming.

    switch(config)#queue-monitor streaming
    switch(config-qm-streaming)#shutdown
    switch(config-qm-streaming)#
    

Configuring Maximum Connections

By default, the switch will accept a maximum of 10 client connections for LANZ data streaming. This maximum can be configured using the max-connections command. If a client connects to the switch after the limit has been reached, an error message is sent and the connection is closed.

Example
This command sets the maximum number of client connections for LANZ data streaming to 50.
switch(config-qm-streaming)#max-connections 50

LANZ Streaming Messages

When streaming is enabled, LANZ sends a message whenever a congestion event or a configuration event occurs. The messages are streamed in Google protocol buffer format.

Configuration Messages

A configuration message is sent whenever a change is made to the LANZ configuration settings on the switch. The switch also sends a configuration message when a new client connection is established.

The configuration message includes the following information:

  • timestamp     time of change in configuration in tens of microseconds (UTC).
  • lanzVersion     LANZ feature version.
  • numOfPorts     number of ports in the switch.
  • segmentSize     segment size.
  • maxQueueSize     maximum queue size in segments.
  • qLenInterval     frequency of updates.
  • intfName     name of the port.
  • switchId     ID of the chip on a multi-chip system.
  • portId     ID of the port.
  • internalPort     “true” if it is an internal port.
  • highThreshold     higher threshold value.
  • lowThreshold     lower threshold value.
Congestion Messages

A congestion message is sent whenever LANZ generates an over-threshold event.

The congestion message includes the following information:

  • timestamp     time of congestion in micro-seconds (UTC).
  • intfName     name of the port.
  • switchId     ID of the chip on a multi-chip system.
  • portId     ID of the port.
  • queueSize     queue size in segments at time of congestion.

Creating the LANZ Client

For a client device to receive streaming data from the LANZ server, it must be running a client application designed to receive LANZ data. Client programs must be based on the Google protocol buffer schema file describing the structure of the congestion and configuration messages which LANZ streams.

Google Protocol Buffers

Google protocol buffers provide an efficient mechanism for serializing LANZ data for streaming. A protocol buffer package is needed in order to run a LANZ client.

The latest version of the Google protocol buffer source code is available at this address: http://code.google.com/p/protobuf/downloads/list

LANZ Message Schema

LANZ client applications must be designed based on the LANZ protocol buffer schema, which defines the format and contents of the streamed messages. The schema file is shown below, and is also available in the Extensions/LANZ directory on this page: https://www.arista.com/en/support/software-download

package LanzProtobuf;

message ConfigRecord { 
required uint64 timestamp = 1; // Time of change in configuration in 
micro-seconds (UTC) 
required uint32 lanzVersion = 2; // LANZ feature version 
required uint32 numOfPorts = 3; // Num of ports in the switch 
required uint32 segmentSize = 4; // Segement size 
required uint32 maxQueueSize = 5; // Maximum queue size in segments 
optional uint32 qLenInterval = 10; // Frequency of update 
message PortConfigRecord { 
required string intfName = 1; // Name of the port 
required uint32 switchId = 2; // Id of the chip on a multi-chip system 
required uint32 portId = 3; // Id of the port 
required bool internalPort = 4; // 'True' if it's an internal port 
required uint32 highThreshold = 5; // Higher threshold 
required uint32 lowThreshold = 6; // Lower threshold 
}

repeated PortConfigRecord portConfigRecord = 6; // Lanz config details of each 
port 
}

message CongestionRecord { 
required uint64 timestamp = 1; // Time of congestion in micro-seconds 
(UTC)
required string intfName = 2; // Name of the port 
required uint32 switchId = 3; // Id of the chip on a multi-chip system 
required uint32 portId = 4; // Id of the port 
required uint32 queueSize = 5; // Queue size in segments at time of 
congestion 
}

message ErrorRecord { 
required uint64 timestamp = 1; // Time of event in micro-seconds (UTC) 
required string errorMessage = 2; // Text message 
}

message LanzRecord { 
optional ConfigRecord configRecord = 1; 
optional CongestionRecord congestionRecord = 2; 
optional ErrorRecord errorRecord = 3; 
} 

Implementation Procedure

The following steps create and install a functional client to receive streamed LANZ data. This procedure assumes a functional Python programming environment.

  1. Download the example client (lanz_client.py) from the Arista website. It is available in the Extensions/LANZ directory on this page: https://www.arista.com/en/support/software-download
  2. Decompress the GPB archive to a directory.
  3. Run the GPB C++ compilation and install. With default flags using GCC on *nix platforms, this will produce a binary called “protoc” in your /usr/local/bin directory.
  4. From the archive root, cd to python, and run the following commands:

    python setup.py build

    python setup.py test

  5. Next, use the protoc compiler to convert the Lanz.proto file into a Python program called Lanz_pb2.py, used by the client. The command to do so is:

    protoc --python_out=. Lanz.proto

    The --python_out=. flag drops the compiled Python program in the directory where you ran the command.

  6. Run lanz_client.py -h to activate the LANZ client.

LANZ Commands

clear queue-monitor length statistics

The clear queue-monitor length statistics command resets the occurrences of all over-threshold events on the switch including global buffer information (if supported).

Command Mode

Privileged EXEC

Command Syntax

clear queue-monitor length statistics

Example

This command resets all over-threshold events and global buffer information on an FM6000 switch.
switch#clear queue-monitor length statistics
switch#

max-connections

The max-connections command sets the maximum number of client connections the switch accepts for streaming LANZ data. The default maximum is 10 connections. To stream LANZ data, you must use the queue-monitor streaming command to enable LANZ data streaming.

Command Mode

Queue-Monitor-Streaming Configuration

Command Syntax

max-connections connections

Parameters

connections     maximum number of simultaneous LANZ streaming client connections the switch will accept. Values range from 1 through 100.

Related Commands

queue-monitor streaming places the switch in queue-monitor-streaming configuration mode.

Example

This command sets the maximum number of client connections the switch accepts for LANZ data streaming to 50.
switch(config-qm-streaming)#max-connections 50
switch(config-qm-streaming)#

queue-monitor length (global configuration mode)

The queue-monitor length (global configuration mode) command enables LANZ with the current settings, or with the default settings if LANZ has not yet been configured. LANZ is enabled by default on Sand platform switches (those with Arad, Jericho, or Qumran chipsets), and disabled by default on all other switches.

When LANZ is enabled, the switch monitors queue lengths on all ports and generates over-threshold events when an output queue becomes congested. Over-threshold event data is available in the following forms:

The no queue-monitor length command entered in global configuration mode disables LANZ and discards LANZ log data, but retains settings. LANZ settings include:

To disable LANZ on an interface, use the no queue-monitor length command in interface configuration mode.

Command Mode

Global Configuration

Command Syntax

queue-monitor length

no queue-monitor length

default queue-monitor length

Examples

  • This command enables LANZ on the switch.
    switch(config)#queue-monitor length
    switch(config)#
  • This command disables LANZ on the switch and discards LANZ data but maintains configurations.
    switch(config)#no queue-monitor length
    switch(config)#
  • This command disables LANZ on Ethernet interface 3/30.
    switch(config)#interface ethernet 3/30
    switch(config-if-Et3/30)#no queue-monitor length
    switch(config-if-Et3/30)#

queue-monitor length cpu thresholds

The queue-monitor length cpu thresholds command sets the queue length threshold to define “congested” on all CPU ports for purposes of LANZ reporting. If LANZ is enabled (see queue-monitor length (global configuration mode)), an over-threshold event is generated when one or more queues on a CPU interface exceed the upper threshold, and over-threshold events continue to be generated until all queue lengths on the interface drop below the lower threshold. (To log these events, use the queue-monitor length log command.) Different monitoring thresholds cannot be set for individual CPU ports.

The no queue-monitor length cpu thresholds and default queue-monitor length cpu thresholds commands reset thresholds to the default values (high: 512 segments; low: 256 segments).

Command Mode

Global Configuration

Command Syntax

queue-monitor length cpu thresholds upper_limit lower_limit

no queue-monitor length cpu thresholds

default queue-monitor length cpu thresholds

Parameters

  • upper_limit     is the queue length in segments that triggers an over-threshold event. Values range from 8 to 16382. Default setting is 512. Segment size varies by platform.
  • lower_limit      When logging is enabled, an over-threshold interface continues generating over-threshold events until all its queues drop back below this length. Must be lower than upper_limit. Values range from 1 to 16382. Default setting is 256.

Examples
  • This command sets the upper queue-length threshold for congestion monitoring on all CPU ports to 1000 segments and the lower limit to 300 segments.
    switch(config)#queue-monitor length cpu thresholds 1000 300
    switch(config)#
  • This command resets the queue-length thresholds for CPU port congestion to the default values of 512 and 256.
    switch(config)#default queue-monitor length cpu thresholds
    switch(config)#

queue-monitor length fabric thresholds

The queue-monitor length fabric thresholds command sets the queue length threshold to define “congested” on all fabric ports for purposes of LANZ reporting. If LANZ is enabled (see queue-monitor length (global configuration mode)), an over-threshold event is generated when one or more queues on a fabric interface exceed the upper threshold, and over-threshold events continue to be generated until all queue lengths on the interface drop below the lower threshold. (To log these events, use the queue-monitor length log command.) Different monitoring thresholds cannot be set for individual fabric ports.

The no queue-monitor length fabric thresholds and default queue-monitor length fabric thresholds commands reset thresholds to the default values (high: 512 segments; low: 256 segments).

Command Mode

Global Configuration

Command Syntax

queue-monitor length fabric thresholds upper_limit lower_limit

no queue-monitor length fabric thresholds

default queue-monitor length fabric thresholds

Parameters

  • upper_limit     is the queue length in segments that triggers an over-threshold event. Values range from 8 to 16382. Default setting is 512. Segment size varies by platform.
  • lower_limit      When logging is enabled, an over-threshold interface continues generating over-threshold events until all its queues drop back below this length. Must be lower than upper_limit. Values range from 1 to 16382. Default setting is 256.

Examples

  • This command sets the upper queue-length threshold for congestion monitoring on all fabric ports to 1000 segments and the lower limit to 300 segments.

    switch(config)#queue-monitor length fabric thresholds 1000 300
    switch(config)#
  • This command resets the queue-length thresholds for fabric port congestion to the default values of 512 and 256.

    switch(config)#default queue-monitor length fabric thresholds
    switch(config)#

queue-monitor length global-buffer log

The queue-monitor length global-buffer log command enables logging of global buffer over-threshold events. When logging is enabled, a log message is generated each time the contents of the global buffer exceed the upper threshold value set for the switch (see queue-monitor length global-buffer thresholds). Once the global buffer is over the threshold, additional messages are generated at a maximum rate of one per interval as long as the buffer value remains above the lower threshold for the switch.

Global buffer logging is disabled by default.

Log messages do not include buffer usage or congestion information. To view this information, use the show queue-monitor length global-buffer command.

The no queue-monitor length global-buffer log and default queue-monitor length global-buffer log commands disable global buffer logging by removing the corresponding queue-monitor length global-buffer log command from running-config. The queue-monitor length global-buffer log command with an interval value of 0 also disables global buffer logging.

Command Mode

Global Configuration

Command Syntax

queue-monitor length global-buffer log interval

no queue-monitor length global-buffer log

default queue-monitor length global-buffer log

Parameters
  • interval     minimum interval in seconds between logged messages.

    • 0     global buffer logging is disabled on the switch (the default setting).

    • 1 to 65535     minimum logging interval (in seconds).

Guidelines

This command is available on FM6000 platform switches.

Examples
  • This command enables global buffer logging with a minimum interval of 10 seconds between messages.

    switch(config)#queue-monitor length global-buffer log 10
  • This command disables global buffer logging on the switch.

    switch(config)#no queue-monitor length global-buffer log

queue-monitor length global-buffer thresholds

The queue-monitor length global-buffer thresholds command sets global buffer thresholds for the switch. An over-threshold event is generated when usage of the global buffer exceeds the upper threshold, and over-threshold events continue to be generated until usage drops below the lower threshold. (To log these events, use the queue-monitor length global-buffer log command.)

The no queue-monitor length global-buffer and default queue-monitor length global-buffer commands disable global buffer reporting.

The no queue-monitor length global-buffer thresholds and default queue-monitor length global-buffer thresholds commands erase custom global buffer threshold settings.

Command Mode

Global Configuration

Command Syntax

queue-monitor length global-buffer thresholds max_segments min_segments

no queue-monitor length global-buffer log

default queue-monitor length global-buffer log

Parameters

  • max_segments     upper threshold in 160-byte segments. Value ranges from 2 to 36864. Default is 10940.
  • min_segments     lower threshold in 160-byte segments. Value ranges from 1 to 36864. Default is 4376.

    Examples
    • This command sets the upper and lower global buffer thresholds to 9000 segments and 3000 segments.

      switch(config)#queue-monitor length global-buffer thresholds 9000 3000
      switch(config)#
    • This command resets the upper and lower global buffer thresholds to their default values.
      switch(config)#no queue-monitor length global-buffer thresholds 9000 3000
      switch(config)#

queue-monitor length global-buffer

The queue-monitor length global-buffer command includes global buffer usage in LANZ reporting.

When global buffer reporting is enabled, over-threshold events are generated when global buffer usage exceeds the upper threshold. To set the threshold value, use the queue-monitor length global-buffer thresholds command. Usage data may be viewed using the show queue-monitor length global-buffer command. To view status and threshold information, use the show queue-monitor length status command.

Global buffer usage is measured in segments of 160 bytes.

The no queue-monitor length global-buffer and default queue-monitor length global-buffer commands disable global buffer usage reporting by removing the corresponding queue-monitor length global-buffer command from running-config.

Command Mode

Global Configuration

Command Syntax

queue-monitor length global-buffer

no queue-monitor length global-buffer

default queue-monitor length global-buffer

Guidelines

This command is available on FM6000 platform switches.

Examples
  • This command enables global buffer monitoring on the switch.

    switch(config)#queue-monitor length global-buffer
    switch(config)#
  • This command disables global buffer monitoring on the switch.

    switch(config)#no queue-monitor length global-buffer
    switch(config)#

queue-monitor length log

The queue-monitor length log command enables logging of queue-length over-threshold events when LANZ is enabled on the switch (see queue-monitor length (global configuration mode)). When logging is enabled, a log message is generated each time one or more queues on an interface exceed the upper threshold value for that interface (see queue-monitor length threshold (Arad/Jericho)). Once an interface is over threshold, additional messages are generated at a maximum rate of one per interval as long as the queue length remains above the lower threshold for that interface. No syslog message is generated when queue length drops back under threshold.

Logging is disabled by default.

Log messages do not include queue length information. To view queue length information, use the show queue-monitor length command.

The queue-monitor length log command with an interval value of 0 disables event logging.

Command Mode

Global Configuration

Command Syntax

queue-monitor length log interval

Parameters

  • interval     minimum interval in seconds between logged messages from a single interface.

    • 0     queue-length logging is disabled on the switch (the default setting).

    • 1 to 65535     minimum logging interval (in seconds).

      • 1 to 65535     minimum logging interval (in seconds).

Examples
  • This command enables over-threshold logging with a minimum interval of 10 seconds between messages for a given interface.

    switch(config)#queue-monitor length log 10
  • This command disables queue-length over-threshold logging on the switch.

     switch(config)#queue-monitor length log 0
  • This is an example of a queue-length log message.

    Oct 27 12:48:22 switch QUEUE_MONITOR-6-LENGTH_OVER_THRESHOLD: Interface
    Ethernet6 queue length is over threshold of 512, current length is 1024.

queue-monitor length mirror destination

The queue-monitor length mirror destination command results in automatically sending traffic experiencing congestion to either the CPU or an Ethernet egress interface destination, once a queue threshold is crossed. Before using this command, first enable LANZ mirroring through the command queue-monitor length mirror.

Command Mode

Global Configuration

Command Syntax

queue-monitor length mirror destination cpu |Ethernet <ports 1-24>

Parameters

ports     any combination of Ethernet ports 1 through 24.

Examples

  • This command configures LANZ traffic sampling for a CPU interface mirror destination.

    switch(config)#queue-monitor length mirror destination cpu
    switch(config)#
  • This command configures LANZ traffic sampling for an Ethernet interface mirror destination for ports 3, 11, and 15 through 20.

    switch(config)#queue-monitor length mirror destination Ethernet 3,11,15-20
    switch(config)#

queue-monitor length mirror

The queue-monitor length mirror command enables LANZ mirroring. As a result, the switch is configured to automatically send congested traffic to either the CPU or an Ethernet egress interface destination, once a queue threshold is crossed. To set the destination for the mirrored traffic, use the queue-monitor length mirror destination command.

Command Mode

Global Configuration

Command Syntax

queue-monitor length mirror

Examples

  • This command enables LANZ traffic sampling.

    switch(config)#queue-monitor length mirror
    switch(config)#
  • This command disables LANZ traffic sampling.

    switch(config)#no queue-monitor length mirror
    switch(config)#

queue-monitor length notifying

The queue-monitor length notifying command enables Notifying Mode on Arad and Jericho switches. By default, LANZ operates in Polling Mode on Arad and Jericho switches. On all other switches, LANZ operates only in Notifying Mode.

When Notifying Mode is enabled, the switch provides detailed congestion information including Start, Update, and End events, rather than only polling the most congested queue in each ASIC. Notifying Mode uses both upper and lower threshold values. Both can be set with the queue-monitor length thresholds command. While a queue is congested, the maximum queue size is updated every five seconds by default; this interval can be configured using the queue-monitor length update-interval command.

The no queue-monitor length notifying and default queue-monitor length notifying commands reset LANZ to the default Polling Mode.

Command Mode

Global Configuration

Command Syntax

queue-monitor length notifying

no queue-monitor length notifying

default queue-monitor length notifying

Guidelines
  • Polling mode is available only on Arad and Jericho platform switches.
  • On Jericho platforms, LANZ will revert to Polling Mode if there are not enough counter resources to operate in Notifying Mode.
  • On Arad platforms, Notifying Mode is incompatible with SSO. Enabling SSO while Notifying Mode is enabled will cause LANZ to revert to Polling Mode.
  • On Arad platforms, Notifying Mode is not available for CPU queues. Use Polling Mode when monitoring congestion on CPU queues on Arad switches.
  • If the switch is rebooted while Notifying Mode is enabled, queue threshold values may be lost.

Examples

  • This command enables Notifying Mode on an Arad or Jericho switch.

    switch(config)#queue-monitor length notifying
    switch(config)#
  • This command disables Notifying Mode on an Arad or Jericho switch, returning LANZ to the default Polling Mode.

    switch(config)#no queue-monitor length notifying
    switch(config)#

queue-monitor length threshold (Arad/Jericho/Qumran)

The queue-monitor length threshold command sets the upper queue-length threshold on Arad, Jericho, and Qumran platforms to define “congested” on the command-mode interface for purposes of LANZ reporting. If LANZ is enabled (see queue-monitor length (global configuration mode)), an over-threshold event is generated when one or more queues on the interface exceed the upper threshold, and over-threshold events continue to be generated until all queue lengths on the interface drop below the lower threshold. (To log these events, use the queue-monitor length log command.)

Entering the no queue-monitor length command in interface configuration mode disables LANZ on the interface. Entering either the queue-monitor length threshold command or the default queue-monitor length threshold command enables LANZ on the interface by removing the no queue-monitor length command from the configuration.

The no queue-monitor length threshold and default queue-monitor length threshold commands erase custom queue length threshold settings for the interface.

Command Mode

Interface-Ethernet Configuration

Command Syntax

queue-monitor length threshold upper_limit

no queue-monitor length

default queue-monitor length

Parameters

upper_limit     is the queue length in bytes that triggers an over-threshold event. Values range from 40962 to 52428800 bytes. Default setting is 52428800.

Guidelines

On Arad, Jericho, and Qumran platforms, the queue length is measured in bytes. Only the upper threshold is configurable using this command, and it is set at a default value of 52428800 bytes. Both upper and lower thresholds can be set using the queue-monitor length thresholds command.

Examples

  • These commands set the upper queue-length threshold on Ethernet interface 3/30 to 40000000 bytes.

    switch(config)#interface ethernet 3/30
    switch(config-if-Et3/30)#queue-monitor length threshold 40000000
    switch(config-if-Et3/30)#
  • These commands reset the upper queue-length threshold on Ethernet interface 3/30 to its default value of 52428800 bytes.

    switch(config)#interface ethernet 3/30
    switch(config-if-Et3/30)#default queue-monitor length threshold
    switch(config-if-Et3/30)#

queue-monitor length thresholds

The queue-monitor length thresholds command sets both upper and lower queue length thresholds to define “congested” on the command-mode interface for purposes of LANZ reporting. If LANZ is enabled (see queue-monitor length (global configuration mode)), an over-threshold event is generated when one or more queues on the interface exceed the upper threshold, and over-threshold events continue to be generated until all queue lengths on the interface drop below the lower threshold. (To log these events, use the queue-monitor length log command.)

Entering the no queue-monitor length command in interface configuration mode disables LANZ on the interface. Entering either the queue-monitor length command or the default queue-monitor length command in interface configuration mode enables LANZ on the interface by removing the no queue-monitor length command from the configuration.

The no queue-monitor length thresholds and default queue-monitor length thresholds commands in interface configuration mode both erase custom queue length threshold settings for the interface.

Command Mode

Interface-Ethernet Configuration

Command Syntax

queue-monitor length thresholds upper_limit lower_limit

no queue-monitor length

default queue-monitor length

Parameters

  • upper_limit     queue length in segments that triggers an over-threshold event. Must be higher than lower_limit. The minimum value is 2. The maximum is the largest number of segments which can be queued before packets are dropped, and varies based on factors including flow control state and private buffer settings. Default setting is 512.
  • lower_limit    lower queue length threshold in segments. When logging is enabled, an over-threshold interface continues generating over-threshold events until all its queues drop back below this length. Must be lower than upper_limit. Values range from 1 to 4806. Default setting is 256.

Guidelines

Queue lengths are measured in 480-byte segments on FM6000 switches, in 208-byte segments on Trident II and Tomahawk switches, in 256-byte segments on Trident 3 switches, and in bytes on Arad and Jericho switches. Default thresholds vary by platform. Both upper and lower thresholds are configurable.

Examples
  • These commands set the upper and lower queue-length thresholds on Ethernet interface 5 to 300 segments and 200 segments.

    switch(config)#interface ethernet 5
    switch(config-if-Et5)#queue-monitor length thresholds 300 200
    switch(config-if-Et5)#
  • These commands reset the upper and lower queue-length thresholds on Ethernet interface 5 to their default values.

    switch(config)#interface ethernet 5
    switch(config-if-Et5)#default queue-monitor length thresholds
    switch(config-if-Et5)#

queue-monitor length update-interval

The queue-monitor length update-interval command sets the interval between congestion updates when LANZ is in Notifying Mode.

The no queue-monitor length update-interval and default queue-monitor length update-interval commands reset the update interval to its default value of 5000000 (5 seconds).

Command Mode

Global Configuration

Command Syntax

queue-monitor length update-interval interval

no queue-monitor length

default queue-monitor length

Parameters

interval     is the time in microseconds between congestion updates. Values range from 80-10000000; default setting is 5000000 (5 seconds).

Examples

  • This command sets the time between congestion updates to 10 seconds.

    switch(config)#queue-monitor length update-interval 10000000
    switch(config)#
  • This command resets the time between congestion updates to its default value of 5 seconds.

    switch(config)#default queue-monitor length update-interval
    switch(config)#

queue-monitor streaming

The queue-monitor streaming command places the switch in queue-monitor-streaming configuration mode. Queue-monitor-streaming configuration mode is not a group change mode; running-config is changed immediately upon command entry. The exit command does not affect running-config.

To enable LANZ data streaming on the switch, use the no show queue-monitor streaming clients command.

The exit command returns the switch to global configuration mode.

Command Mode

Global Configuration

Command Syntax

queue-monitor streaming

Commands Available in queue-monitor streaming Configuration Mode

Example

This command places the switch in queue-monitor streaming configuration mode.
switch(config)#queue-monitor streaming
switch(config-qm-streaming)#

show queue-monitor length all

The show queue-monitor length all command displays all available over-threshold event records on the switch including global buffer information, with the most recent events listed first.

LANZ must be enabled to use this command (see queue-monitor length (global configuration mode)). If LANZ is disabled, the command displays “queue-monitor is disabled.”

Command Mode

EXEC

Command Syntax

show queue-monitor length all

Guidelines

This command is available on FM6000 platform switches.

Example

This command displays all available LANZ records from the switch.
switch>show queue-monitor length all

Report generated at 2013-04-01 13:23:13
E-End, U-Update, S-Start, TC-Traffic Class
GH-High, GU-Update, GL-Low
Segment size for E, U and S congestion records is 480 bytes
Segment size for GL, GU and GH congestion records is 160 bytes
* Max queue length during period of congestion
+ Period of congestion exceeded counter
------------------------------------------------------------------------------
Type    Time                   Intf    Congestion     Queue       Time of Max
                               (TC)    duration       length      Queue length
                                       (usecs)        (segments)  relative to
                                                                  congestion
                                                                  start
                                                                  (usecs)
------------------------------------------------------------------------------
E  0:00:00.07567 ago         Et22(7)   >=71 mins      20*         30us
GU 0:00:00.15325 ago         N/A       N/A            5695        N/A 
U  0:00:00.19859 ago         Et4(1)    N/A            5693        N/A 
GU 0:00:00.95330 ago         N/A       N/A            5696        N/A 
U  0:00:00.99859 ago         Et4(1)    N/A            5695        N/A 
E  0:00:01.28821 ago         Et44(1)   9672us         2502*       7294us
S  0:00:01.17591 ago         Et22(7)   N/A            26          N/A
U  0:00:03.08248 ago         Et44(1)   N/A            50          N/A
S  12days,8:56:44.07567 ago  Et44(1)   N/A            20          N/A
switch>

show queue-monitor length cpu

The show queue-monitor length cpu command displays LANZ data for CPU ports on the switch. On Trident II and Tomahawk platforms, the “Interface” column identifies the CPU port by its card slot and chip index.

LANZ must be enabled to use this command (see queue-monitor length (global configuration mode)). If LANZ is disabled, the command displays “queue-monitor is disabled.”

Command Mode

EXEC

Command Syntax

show queue-monitor length cpu

Examples
  • This command displays LANZ data for CPU ports on a Trident II or Tomahawk switch.

    switch>show queue-monitor length cpu
    Report generated at 2017-03-10 15:24:11
    E-End, U-Update, S-Start, TC-Traffic Class
    Segment size for E, U and S congestion records is 208 bytes
    * Max queue length during period of congestion
    + Period of congestion exceeded counter
    ----------------------------------------------------------------------------------------
    TypeTime InterfaceCongestion QueueTime of MaxFabric
     (TC) duration length Queue length Peer
    (usecs)(segments) relative to
    congestion
    start
    (usecs)
    ----------------------------------------------------------------------------------------
     E 0:02:24.19153 agoCpu0/0(39) 16669811 271* 0
     U 0:02:25.81126 agoCpu0/0(39) N/A270N/A
     U 0:02:30.81126 agoCpu0/0(39) N/A270N/A
     U 0:02:35.81128 agoCpu0/0(39) N/A270N/A
     U 0:02:40.81129 agoCpu0/0(39) N/A270N/A
     U 0:02:40.81630 agoCpu0/0(39) N/A270N/A
     U 0:02:40.82130 agoCpu0/0(39) N/A270N/A
     U 0:02:40.82631 agoCpu0/0(39) N/A270N/A
     U 0:02:40.83132 agoCpu0/0(39) N/A270N/A
     U 0:02:40.83632 agoCpu0/0(39) N/A270N/A
     U 0:02:40.84132 agoCpu0/0(39) N/A270N/A
     U 0:02:40.84633 agoCpu0/0(39) N/A270N/A
     U 0:02:40.85133 agoCpu0/0(39) N/A270N/A
     U 0:02:40.85634 agoCpu0/0(39) N/A270N/A
     S 0:02:40.86134 agoCpu0/0(39) N/A271N/A
  • This command displays LANZ data for CPU ports on an FM6000 switch.

    switch>show queue-monitor length cpu
    Report generated at 2017-03-10 15:17:57
    E-End, U-Update, S-Start, TC-Traffic Class
    GH-High, GU-Update, GL-Low
    Segment size for E, U and S congestion records is 480 bytes
    Segment size for GL, GU and GH congestion records is 160 bytes
    * Max queue length during period of congestion
    + Period of congestion exceeded counter
    -------------------------------------------------------------------------------
    Type    Time                   Intf    Congestion     Queue       Time of Max
                                   (TC)    duration       length      Queue length
                                           (usecs)        (segments)relative to
                                                                      congestion
                                                                      start
                                                                      (usecs)
    -------------------------------------------------------------------------------
     E   0:04:41.17456 ago         Cpu(11)   29            1024*       0
     S   0:04:41.17459 ago         Cpu(11)   N/A           1024        N/A
     E   0:04:41.17463 ago         Cpu(11)   15926108      206*        33872
     U   0:04:42.09651 ago         Cpu(11)   N/A           205         N/A
     U   0:04:47.09710 ago         Cpu(11)   N/A           205         N/A
     U   0:04:52.09769 ago         Cpu(11)   N/A           205         N/A
     U   0:04:57.09826 ago         Cpu(11)   N/A           205         N/A
    
    
  • This command displays LANZ data for CPU ports on an Arad or Jericho switch in Polling Mode.

    switch>show queue-monitor length cpu
    Report generated at 2017-03-10 16:04:28
    E-End, S-Start, P-Polling, TC-Traffic Class
    * Max queue length during period of congestion
    TypeTimeIntf(TC) QueueDuration Ingress
     LengthPort-set
     (bytes)(usecs)
    ---- ------------------ ---------------------- ---------- ---------- --------
    P0:00:31.48474 agoCoppSystemL2Ucast(5)1048608020184965Et1-24
  • This command displays LANZ data for CPU ports on an Arad or Jericho switch in Notifying Mode.

    switch>show queue-monitor length cpu
    Report generated at 2017-03-10 16:08:58
    E-End, S-Start, P-Polling, TC-Traffic Class
    * Max queue length during period of congestion
    TypeTime Intf(TC)Queue Duration Ingress
     Length Port-set
     (bytes) (usecs)
    ----- ------------------ ----------------------- ----------- ---------- --------
    E 0:00:03.11739 agoCoppSystemL2Ucast(5) 10485760* 20700629 Et1-24
    U 0:00:04.01513 agoCoppSystemL2Ucast(5) 10485760 N/A Et1-24
    U 0:00:08.94918 agoCoppSystemL2Ucast(5) 10485760 N/A Et1-24
    U 0:00:13.88323 agoCoppSystemL2Ucast(5) 10485760 N/A Et1-24
    U 0:00:18.81728 agoCoppSystemL2Ucast(5) 10485760 N/A Et1-24
    U 0:00:23.74758 agoCoppSystemL2Ucast(5) 10485760 N/A Et1-24
    S 0:00:23.81802 agoCoppSystemL2Ucast(5) 10485760 N/A Et1-24

show queue-monitor length csv

The show queue-monitor length csv command displays LANZ records in comma-separated value (CSV) format with the oldest samples displayed first.

LANZ must be enabled to use this command (see queue-monitor length (global configuration mode)). If LANZ is disabled, the command displays “queue-monitor is disabled.”

Command Mode

EXEC

Command Syntax

show queue-monitor length csv

Example

This command displays LANZ records in CSV format.
switch>show queue-monitor length csv

Report generated at 2016-02-09 22:57:50
Type,Time,Interface,Duration(usecs),Queue-Length,Time-Of-Max-Queue(usecs),Laten
cy(usecs),Tx-Drops
 S,2016-02-09 22:53:05.70596,Et29(11),N/A,2590,N/A,60.088,0
 U,2016-02-09 22:53:05.71098,Et29(11),N/A,2590,N/A,60.088,216555
 U,2016-02-09 22:53:05.71600,Et29(11),N/A,2590,N/A,60.088,215546
switch>

show queue-monitor length drops

The show queue-monitor length drops command displays a report of cumulative transmission drop totals for a range of interfaces or for all interfaces. Output can be limited to a specified number of seconds or records. The most recent events are listed first. By default, the command displays data for all interfaces, limited to the last 1000 records. Newest events are listed first.

LANZ must be enabled to use this command (see queue-monitor length (global configuration mode)). If LANZ is disabled, the command displays “queue-monitor is disabled.”

Command Mode

EXEC

Command Syntax

show queue-monitor length [INTERFACES][FACTOR]drops

Parameters

  • INTERFACES     interface type and number for report. Values include:

    • <no parameter>     displays information for all interfaces.
    • ethernet e-range     e-range formats include a number, number range, or comma-delimited list of numbers and ranges.
  • FACTOR     limiting parameter for report. Values include:

    • <no parameter>     displays the last 1000 records.
    • limit number samples    displays the last number records.
    • limit number seconds     displays all records generated during the last number seconds.

      Value of number ranges from 1 to 1000000.

Guidelines

This command is available on FM6000, Trident II, Trident 3, and Tomahawk platform switches.

Example
  • This command displays the last 10 records of transmission drop data on an FM6000 switch.

    switch>show queue-monitor length limit 10 samples drops 
    Report generated at 2017-03-10 15:25:29
    TimeInterfaceTX Drops
    -----------------------------------------------------------------
    0:12:13.34425 ago Cpu419
    0:12:13.34428 ago Cpu371
    0:12:13.34433 ago Cpu9913826
    0:12:14.26621 ago Cpu53775812
    0:12:19.26680 ago Cpu53775740
    0:12:24.26738 ago Cpu53775714
    0:12:29.26796 ago Cpu1073
    0:12:29.26806 ago Cpu1068
    0:12:29.26816 ago Cpu1074
    0:12:29.26825 ago Cpu1071
  • This command displays the last 10 records of transmission drop data on a Trident II or Tomahawk switch.

    switch>show queue-monitor length limit 10 samples drops 
    
    Report generated at 2017-03-10 15:25:34
    TimeInterface(TC)TX Drops
    -----------------------------------------------------------------
    0:03:47.06553 ago Cpu0/0(39) 17419818
    0:03:48.68527 ago Cpu0/0(39) 53773707
    0:03:53.68527 ago Cpu0/0(39) 53773770
    0:03:58.68528 ago Cpu0/0(39) 53773763
    0:04:03.68529 ago Cpu0/0(39) 53878
    0:04:03.69030 ago Cpu0/0(39) 53777
    0:04:03.69530 ago Cpu0/0(39) 53917
    0:04:03.70031 ago Cpu0/0(39) 53880
    0:04:03.70532 ago Cpu0/0(39) 53786
    0:04:03.71032 ago Cpu0/0(39) 53782
    switch>

show queue-monitor length ethernet

The show queue-monitor length ethernet command displays a report of recent over-threshold events for a range of interfaces, with the newest events listed first.

LANZ must be enabled to use this command (see queue-monitor length (global configuration mode)). If LANZ is disabled, the command displays “queue-monitor is disabled.”

Command Mode

EXEC

Command Syntax

show queue-monitor length ethernet e-range

Parameters

e-range     the range of interfaces to be included in the report; formats include a number, number range, or comma-delimited list of numbers and ranges

Examples
  • This command displays the last 1000 records for Ethernet interface 9 on an FM6000 platform switch.

    switch>show queue-monitor length ethernet 9
    Report generated at 2017-03-10 15:33:35
    E-End, U-Update, S-Start, TC-Traffic Class
    GH-High, GU-Update, GL-Low
    Segment size for E, U and S congestion records is 480 bytes
    Segment size for GL, GU and GH congestion records is 160 bytes
    * Max queue length during period of congestion
    + Period of congestion exceeded counter
    -------------------------------------------------------------------------------
    TypeTime IntfCongestion Queue Time of Max
     (TC)duration lengthQueue length
     (usecs)(segments)relative to
    congestion
    start
    (usecs)
    -------------------------------------------------------------------------------
     E 0:00:24.82515 ago Et9(1)227379675623* 26651
     U 0:00:27.55841 ago Et9(1)N/A 5620N/A
     U 0:00:32.55899 ago Et9(1)N/A 5620N/A
     U 0:00:37.55957 ago Et9(1)N/A 5621N/A
     U 0:00:42.56015 ago Et9(1)N/A 5621N/A
     U 0:00:47.56073 ago Et9(1)N/A 5621N/A
     U 0:00:47.56083 ago Et9(1)N/A 5620N/A
     U 0:00:47.56093 ago Et9(1)N/A 5620N/A
     U 0:00:47.56103 ago Et9(1)N/A 5620N/A
     U 0:00:47.56113 ago Et9(1)N/A 5620N/A
    switch>
    
    
  • This command displays the last 1000 records for Ethernet interface 23/3 on a Trident II or Tomahawk platform switch.

    switch>show queue-monitor length Ethernet 23/3
    Report generated at 2017-03-10 15:38:01
    E-End, U-Update, S-Start, TC-Traffic Class
    Segment size for E, U and S congestion records is 208 bytes
    * Max queue length during period of congestion
    + Period of congestion exceeded counter
    -----------------------------------------------------------------------------------------------
    TypeTime InterfaceCongestion QueueTime of MaxFabric
     (TC) duration length Queue length Peer
    (usecs)(segments) relative to
    congestion
    start
    (usecs)
    -----------------------------------------------------------------------------------------------
     E 0:00:29.49376 ago Et23/3(1)22388908 7879*365268
     U 0:00:31.83332 ago Et23/3(1)N/A7877 N/A
     U 0:00:36.83288 ago Et23/3(1)N/A7877 N/A
     U 0:00:41.83289 ago Et23/3(1)N/A7877 N/A
     U 0:00:46.83289 ago Et23/3(1)N/A7877 N/A
     U 0:00:51.83260 ago Et23/3(1)N/A7877 N/A
     U 0:00:51.83760 ago Et23/3(1)N/A7877 N/A
     U 0:00:51.84261 ago Et23/3(1)N/A7878 N/A
     U 0:00:51.84762 ago Et23/3(1)N/A7877 N/A
     U 0:00:51.85263 ago Et23/3(1)N/A7877 N/A
     U 0:00:51.85763 ago Et23/3(1)N/A7877 N/A
     U 0:00:51.86264 ago Et23/3(1)N/A7877 N/A
     U 0:00:51.86765 ago Et23/3(1)N/A7878 N/A
     U 0:00:51.87265 ago Et23/3(1)N/A7877 N/A
     U 0:00:51.87766 ago Et23/3(1)N/A7877 N/A
     S 0:00:51.88267 ago Et23/3(1)N/A1710 N/A
    switch>
    
    
  • This command displays the last 1000 records for Ethernet interface 24 on an Arad or Jericho platform switch in Polling Mode.

    switch> show queue-monitor length Ethernet 24
    Report generated at 2017-03-10 16:04:28
    E-End, S-Start, P-Polling, TC-Traffic Class
    * Max queue length during period of congestion
    Type TimeIntf(TC)QueueDurationIngress
     Length Port-set
     (bytes)(usecs)
    ---------- ----------------------- --------------- -------------- ----------- --------
    P0:00:04.81587 ago Et24(3) 36126720 4030092 Et1-24
    switch>
  • This command displays the last 1000 records for Ethernet interface 24 on an Arad or Jericho platform switch in Notifying Mode.

    switch> show queue-monitor length Ethernet 24
    Report generated at 2017-03-10 16:08:58
    E-End, S-Start, P-Polling, TC-Traffic Class
    * Max queue length during period of congestion
    Type TimeIntf(TC) Queue DurationIngress
    LengthPort-set
    (bytes) (usecs)
    ---------- ----------------------- ----------- --------------- -------------- --------
    E0:00:03.11739 ago Et24(2)36126720* 20700629Et9-20,54/1-4
    U0:00:04.01513 ago Et24(2)36126720N/A Et9-20,54/1-4
    U0:00:08.94918 ago Et24(2)36126720N/A Et9-20,54/1-4
    U0:00:13.88323 ago Et24(2)36126720N/A Et9-20,54/1-4
    U0:00:18.81728 ago Et24(2)36126720N/A Et9-20,54/1-4
    U0:00:23.74758 ago Et24(2)36126720N/A Et9-20,54/1-4
    S0:00:23.81802 ago Et24(2)36126720N/A Et9-20,54/1-4
    switch>
Note: The non-sequential listing of ingress ports shown here is specific to Jericho switches; interfaces on Arad switches are always displayed sequentially.

show queue-monitor length global-buffer

The show queue-monitor length global-buffercommand displays a report of recent high usage, low usage and update events for the global buffer. Newest events are listed first.

LANZ must be enabled to use this command (see queue-monitor length (global configuration mode)). If LANZ is disabled, the command displays “queue-monitor is disabled.”

Command Mode

EXEC

Command Syntax

show queue-monitor length global-buffer

Guidelines

This command is available on FM6000 platform switches.

Example

  • This command displays the global buffer event records for the switch.

    switch>show queue-monitor length global buffer
    Report generated at 2013-04-01 14:30:07
    GH-High, GU-Update, GL-Low
    Segment size = 160 bytes
    * Max buffer usage during period of congestion
    -------------------------------------------------------------------------------
    -
    Type        Time                       Buffer      Congestion     Time of Max
                                           usage       duration       buffer usage
                                           (segments)  (usecs)        relative to
                                                                      GH (usecs)
    -------------------------------------------------------------------------------
    -
    GE 0:04:04.49547 ago                   3121*       20786516       3418
    GU 0:04:05.27967 ago                   3120        N/A            N/A
    GU 0:04:10.27968 ago                   3120        N/A            N/A
    GU 0:04:25.28163 ago                   3118        N/A            N/A
    GU 0:04:25.28173 ago                   3118        N/A            N/A
    GU 0:04:25.28182 ago                   2963        N/A            N/A
    GU 0:04:25.28192 ago                   1916        N/A            N/A
    GS 0:04:25.28201 ago                   913         N/A            N/A
    switch>
    

show queue-monitor length limit

The show queue-monitor length limit command displays a report of recent over-threshold events for a range of interfaces or for all interfaces, limited by a specified number of records.

LANZ must be enabled to use this command (see queue-monitor length (global configuration mode)). If LANZ is disabled, the command displays “queue-monitor is disabled.”

Command Mode

EXEC

Command Syntax

show queue-monitor length limit [INTERFACES] number

Parameters

  • INTERFACES     interface type and number for report. Values include:

    • <no parameter>     displays information for all interfaces.
    • ethernet e-range   e-range formats include a number, number range, or comma-delimited list of numbers and ranges
  • number     number of records to display. Values range from 1 to 1000000.

Example

This command displays the last 100 records for Ethernet interfaces 6 through 8.
switch>#show queue-monitor length ethernet 6-8 limit 100 samples
Report generated at 2010-01-01 12:56:13
Time                        Interface Queue length (segments, 1 to 512 bytes)
----------------------------------------------------------------------------
0:00:07.43393 ago           Et6         1049
0:00:39.22856 ago           Et7         2039
1 day, 4:33:23.12345 ago    Et6         1077
switch>

show queue-monitor length statistics

The show queue-monitor length statistics command displays LANZ statistics for all interfaces, showing the traffic class and number of recorded congestion events for each interface.

LANZ must be enabled to use this command (see queue-monitor length (global configuration mode)). If LANZ is disabled, the command displays “queue-monitor is disabled.”

Command Mode

EXEC

Command Syntax

show queue-monitor length statistics

Example

This command displays LANZ statistics for all interfaces on the switch.
switch> show queue-monitor length statistics

Report generated at 2016-02-09 22:59:56
Interface      Traffic Class  Count
---------------------------------------------------------
Et29            11             1 

show queue-monitor length status

The show queue-monitor length status command displays the current LANZ configuration for the switch and for each interface. On certain platforms, the status of global buffer monitoring and per-linecard LANZ mode are displayed.

Command Mode

EXEC Global Configuration

Command Syntax

show queue-monitor length status

Guidelines

On FM6000 platform switches, this command includes status information about global buffer monitoring.

On Arad and Jericho based linecards, if LANZ is globally enabled (using the queue-monitor length command), the command displays the monitoring mode per-linecard.

On Arad and Jericho switches, even when all linecards are configured in Notifying Mode (using the queue-monitor length notifying command), some linecards may still run LANZ in Polling Mode under the following circumstances:

  • On Arad-based linecards, LANZ falls back to Polling Mode when SSO redundancy mode is configured on the card (here, the mode is shown as “polling due to SSO configured”).

    • On Jericho-based linecards, LANZ may run in Polling Mode when many features that use the switch’s statistic capabilities have been configured (here, the mode is shown as “polling due to counters exhausted”).

Examples

  • This command displays the current LANZ configuration on an FM6000 device.

    switch#show queue-monitor length status
    queue-monitor length enabled
    queue-monitor length packet sampling is disabled
    queue-monitor length update interval in micro seconds:5000000
    Global Buffer Monitoring
    ------------------------
    Global buffer monitoring is enabled
    Segment size in bytes : 160
    Total buffers in segments : 49152
    High threshold : 16862
    Low threshold :6745
    
    
    Per-Interface Queue Length Monitoring
    -------------------------------------
    Queue length monitoring is enabled
    Segment size in bytes : 480
    Maximum queue length in segments :5621
    Port thresholds in segments:
    Port High thresholdLow threshold Mirroring Enabled
    Cpu 512256True
    Et1 512256True
    Et2 512256True
    Et3 512256True
    Et4 512256True
    Et5 512256True
    Et6 512256True
    Et7 512256True
    
    
    switch#
    
    
  • This command displays the current LANZ configuration on a Trident II or Tomahawk device.

    switch#show queue-monitor length status
    queue-monitor length enabled
    queue-monitor length packet sampling is disabled
    queue-monitor length update interval in micro seconds:5000000
    Per-Interface Queue Length Monitoring
    -------------------------------------
    Queue length monitoring is enabled
    Segment size in bytes : 208
    Maximum queue length in segments : 16382
    Port thresholds in segments:
    Port High thresholdLow threshold 
    Cpu 512256
    Et1/1 512256
    Et1/2 512256
    Et1/3 512256
    Et1/4 512256
    Et2/1 512256
    Et2/2 512256
    Et2/3 512256
    
    switch#
  • This command displays the current LANZ configuration on an Arad or Jericho device.

    switch#show queue-monitor length status
    queue-monitor length enabled
    queue-monitor length packet sampling is disabled
    queue-monitor length update interval in micro seconds: 5000000
    Per-Interface Queue Length Monitoring
    -------------------------------------
    Queue length monitoring is enabled
    Queue length monitoring mode is notifying
    Queue length monitoring status is:
    Linecard3 polling due to SSO configured
    Linecard4 polling due to SSO configured
    Linecard5 polling due to SSO configured
    Linecard6 polling due to SSO configured
    Maximum queue length in bytes : 524288000
    Port thresholds in bytes:
    Port High threshold    Low threshold     Warnings
    Cpu 6553632768
    Et3/1/1          52428802621440
    Et3/1/2          52428802621440
    Et3/1/3          52428802621440
    Et3/1/4          52428802621440
    Et3/1/5          52428802621440
    Et3/1/6          52428802621440
    Et3/1/7          52428802621440
    Et3/1/8          52428802621440
    
  • This command displays the current LANZ configuration on an Arad or Jericho device with LANZ disabled globally. Per-linecard LANZ mode status is not displayed.

    switch(config)#show queue-monitor length status
    queue-monitor length disabled
    queue-monitor length packet sampling is disabled
    queue-monitor length update interval in micro seconds: 5000000
    Per-Interface Queue Length Monitoring
    -------------------------------------
    Queue length monitoring is disabled
    Queue length monitoring mode is notifying
    Maximum queue length in bytes : 524288000
    Port thresholds in bytes:
    Port High threshold    Low threshold     Warnings
    Cpu 6553632768
    Et3/1/1          52428802621440
    Et3/1/2          52428802621440
    Et3/1/3          52428802621440
    Et3/1/4          52428802621440
    Et3/1/5          52428802621440
    Et3/1/6          52428802621440
    Et3/1/7          52428802621440
    Et3/1/8          52428802621440

show queue-monitor length tx-latency

The show queue-monitor length tx-latency command displays the latency data of recent LANZ events for a range of interfaces or for all interfaces. Output can be limited to a specified number of seconds or records. The most recent events are listed first. By default, the command displays data for all interfaces, limited to the last 1000 records. Newest events are listed first.

LANZ must be enabled to use this command (see queue-monitor length (global configuration mode)). If LANZ is disabled, the command displays “queue-monitor is disabled.”

Command Mode

EXEC

Command Syntax

show queue-monitor length [INTERFACES][FACTOR] tx-latency

Parameters
  • INTERFACES     interface type and number for report. Values include:

    • <no parameter>     displays information for all interfaces.
    • ethernet e-range     e-range formats include a number, number range, or comma-delimited list of numbers and ranges.
  • FACTOR     limiting parameter for report. Values include:

    • <no parameter>     displays the last 1000 records.
    • limit number samples     displays the last number records.
    • limit number seconds     displays all records generated during the last number seconds.

      Value of number ranges from 1 to 1000000.

Guidelines

This command is available on FM6000, Trident II, Trident 3, and Tomahawk platform switches.

Example

This command displays transmission latency data for the last 1000 LANZ events on the switch.
switch>show queue-monitor length tx-latency

Report generated at 2017-03-10 15:40:02
TimeInterface(TC)Tx-Latency (usecs)
-----------------------------------------------------------------
0:02:29.99222 ago Et23/3(1)724.868
0:02:32.33178 ago Et23/3(1)724.684
0:02:37.33134 ago Et23/3(1)724.684
0:02:42.33135 ago Et23/3(1)724.684
0:02:47.33135 ago Et23/3(1)724.684
0:02:52.33106 ago Et23/3(1)730.985
switch>

show queue-monitor length

The show queue-monitor length command displays a report of recent over-threshold events for all interfaces, limited to the last 1000 records, with the newest events listed first.

LANZ must be enabled to use this command (see queue-monitor length (global configuration mode)). If LANZ is disabled, the command displays “queue-monitor is disabled.”

To limit the output to a specified number of seconds and/or records, use the show queue-monitor length limit command.

Command Mode

EXEC

Command Syntax

show queue-monitor length

Examples

  • This command displays the last 1000 LANZ records on an Arad or Jericho platform switch in Polling Mode.

    switch>show queue-monitor length
    Report generated at 2017-03-10 16:04:28
    E-End, S-Start, P-Polling, TC-Traffic Class
    * Max queue length during period of congestion
    Type       Time                    Intf(TC)      Queue      Duration    Ingress
                                                     Length                 Port-set
                                                     (bytes)    (usecs)
    ---------- ----------------------- ------------- ---------- ----------- --------
    P          0:00:04.81587 ago       Et15(3)       36126720    4030092     Et1-24
    switch>
  • This command displays the last 1000 LANZ records on an Arad or Jericho platform switch in Notifying Mode.

    switch>show queue-monitor length
    Report generated at 2017-03-10 16:08:58
    E-End, S-Start, P-Polling, TC-Traffic Class
    * Max queue length during period of congestion
    Type       Time                    Intf(TC)       Queue      Duration    Ingress
                                                      Length                 Port-set
                                                      (bytes)    (usecs)
    ---------- ----------------------- -------------- ---------- -----------------
    E          0:00:03.11739 ago       Et24(2)        36126720*  20700629    Et9-20,54/1-4
    U          0:00:04.01513 ago       Et24(2)        36126720    N/A        Et9-20,54/1-4
    U          0:00:08.94918 ago       Et24(2)        36126720    N/A        Et9-20,54/1-4
    U          0:00:13.88323 ago       Et24(2)        36126720    N/A        Et9-20,54/1-4
    U          0:00:18.81728 ago       Et24(2)        36126720    N/A        Et9-20,54/1-4
    U          0:00:23.74758 ago       Et24(2)        36126720    N/A        Et9-20,54/1-4
    S          0:00:23.81802 ago       Et24(2)        36126720    N/A        Et9-20,54/1-4
    switch>
  • This command displays the last 1000 LANZ records on an FM6000, Trident II, Trident 3, or Tomahawk platform switch.

    switch>show queue-monitor length
    Report generated at 2017-03-10 14:57:12
    E-End, U-Update, S-Start, TC-Traffic Class
    Segment size for E, U and S congestion records is 208 bytes
    * Max queue length during period of congestion
    + Period of congestion exceeded counter
    -----------------------------------------------------------------------------------------
    TypeTime InterfaceCongestion QueueTime of Max Fabric
     (TC) duration length Queue lengthPeer
    (usecs)(segments) relative to
     congestion
     start
     (usecs)
    -----------------------------------------------------------------------------------------
     E 0:08:04.45352 ago Et23/3(13) 22704753 5743*0
     U 0:08:07.10807 ago Et23/3(13) N/A5742 N/A
     U 0:08:12.10808 ago Et23/3(13) N/A5742 N/A
     U 0:08:17.10809 ago Et23/3(13) N/A5742 N/A
     U 0:08:22.10810 ago Et23/3(13) N/A5742 N/A
     U 0:08:27.10810 ago Et23/3(13) N/A5742 N/A
     U 0:08:27.11311 ago Et23/3(13) N/A5741 N/A
     U 0:08:27.11811 ago Et23/3(13) N/A5742 N/A
     U 0:08:27.12312 ago Et23/3(13) N/A5742 N/A
     U 0:08:27.12812 ago Et23/3(13) N/A5743 N/A
     U 0:08:27.13315 ago Et23/3(13) N/A5743 N/A
     U 0:08:27.13816 ago Et23/3(13) N/A5743 N/A
     U 0:08:27.14319 ago Et23/3(13) N/A5742 N/A
     U 0:08:27.14822 ago Et23/3(13) N/A5743 N/A
     U 0:08:27.15322 ago Et23/3(13) N/A5742 N/A
     S 0:08:27.15828 ago Et23/3(13) N/A2064 N/A
    switch>

show queue-monitor streaming clients

The show queue-monitor streaming clients command displays the number of presently connected clients through LANZ streaming, and also displays their host-names. Ensure that both LANZ and LANZ streaming are enabled in order to use this command.

Command Mode

EXEC

Command Syntax

show queue-monitor streaming clients

Example

This command displays the number of clients connected to LANZ streaming.
switch#show queue-monitor streaming clients
Number of clients connected: 3
--------------------------------
172.20.63.161:6565
172.24.17.58:42
172.38.54.142:333

shutdown (queue-monitor-streaming configuration)

The shutdown command disables the streaming of LANZ data to external clients. The no shutdown command enables LANZ data streaming. Streaming is disabled by default.

Command Mode

Queue-Monitor-Streaming Configuration

Command Syntax

shutdown

no shutdown

Example

These commands enable the streaming of LANZ data on the switch.

switch(config)#queue-monitor streaming
switch(config-qm-streaming)#no shutdown
switch(config-qm-streaming)#

tcpdump queue-monitor

The tcpdump queue-monitor command exports congested traffic to a packet capture device or another tool for analysis, or directly to the switch CPU for inspection.

Command Mode

Global Configuration

Command Syntax

tcpdump queue-monitor

tcpdump queue-monitor [file | filecount | filter | lookup-names | max-file-size | packet-count | size | verbose]

Parameters
  • file     output file.

    • certificate:     certificate file.

      • file:     standard file.
      • flash:     flash file.
      • sslkey:     sslkey file.
      • usb1:     usb1 file.
  • filecount     specify the number of output files: 1 to 100.
  • filter     set the filtering expression to select which packets will be dumped.
  • lookup-names     enable reverse DNS lookups.
  • max-file-size     specify the maximum file size by entering 1 to 100 million bytes.
  • packet-count     specify 1 to 10000 packets to capture.
  • size     specify the maximum number of bytes to dump per packet with a size of 1 to 65536 bytes.
  • verbose     enable verbose mode.

Example

This command inspects traffic on the switch.
switch(config)#tcpdump queue-monitor
tcpdump: WARNING: lanz: no IPv4 address assigned
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on lanz, link-type EN10MB (Ethernet), capture size 65535 bytes
...
0 packets captured
0 packets received by filter
0 packets dropped by kernel
switch(config)#
..