Virtual LANs (VLANs)
This chapter describes Arista’s Virtual LANs (VLANs) implementation and MAC address tables.
sections in this chapter include:
VLAN Introduction
Arista switches support industry standard 802.1q VLANs. Arista eos provides tools to manage and extend VLANs throughout the data center network.
VLAN Conceptual Overview
VLAN Definition
A virtual local area network (VLAN) allows a group of devices to communicate as if they were in the same network regardless of their physical location. VLANs are layer 2 structures based on the 802.1Q standard.
These parameters are associated with a VLAN:
- VLAN number (1-4094): VLAN numbers uniquely identify the VLAN within a network. VLAN 1 exists by default; all other VLANs only exist after they are configured.
- VLAN name (optional): The VLAN name is a text string that describes the VLAN.
- VLAN state (active or suspended): The state specifies the VLAN transmission status within the switch. In the suspended state, VLAN traffic is blocked on all switch ports. The default state is active.
VLANs define layer 2 broadcast domains in a layer 2 network, in which each device can receive broadcast frames sent by any other within the domain. Switches accommodating multiple broadcast domains serve as multi-port bridges where each broadcast domain is a distinct virtual bridge. Traffic does not pass directly between different VLANs within a switch or between two switches.
VLAN Switching
Ethernet and port channel interfaces are configured as switched ports by default. Switched ports are configurable as members of one or more VLANs. Switched ports ignore all IP-level configuration commands, including IP address assignments.
VLAN Trunking and Trunk Groups
Trunking extends multiple VLANs beyond the switch through a common interface or port channel.
A trunk group is the set of physical interfaces that comprise the trunk and the collection of VLANs whose traffic is carried on the trunk. The traffic of a VLAN that belongs to one or more trunk groups is carried only on ports that are members of trunk groups to which the VLAN belongs, i.e., VLANs configured in a trunk group are pruned of all ports that are not associated with the trunk group. See the Trunk Ports example section for further details.
VLAN traffic is carried through Ethernet or LAG ports. A port’s switchport mode defines the number of VLANs for which the port can carry traffic.
- Access ports carry traffic for one VLAN – the access VLAN. Access ports associate untagged frames with the access VLAN. Access ports drop tagged frames that are not tagged with the access VLAN.
- Trunk ports carry traffic for multiple VLANs. Tag frames specify the VLAN for which trunk ports process packets.
Q-in-Q Trunking
A Q-in-Q network is a multi-tier layer 2 VLAN network. A typical Q-in-Q network is composed of a service provider network (tier 1) where each node connects to a customer network (tier 2).
802.1ad is a networking standard that supports Q-in-Q networks by allowing multiple 802.1Q tags in an Ethernet frame.
Each interface in a customer network is assigned to a customer-VLAN (c-VLAN). Packets in c-VLANs contain 802.1q tags that switch traffic within the network. c-VLANs access the service provider VLAN (s-VLAN) through a provider switch. Customer switch ports connect to an s-VLAN through provider switch edge ports, which are configured as dot1q ports and operate as follows:
- Inbound traffic (from customer switches): adds an s-VLAN tag, then forwards packets to the provider network.
- Outbound traffic (to customer switches): removes the s-VLAN tag, then forwards packets to the customer network.
TPID (Configurable Ethertypes)
By default, VLAN-tagged packets carry a tag protocol identifier (TPID) of 0x8100. On some Arista platforms, however, the TPID of a switchport can be modified in accordance with IEEE 802.1ad to allow for the use of 802.1q TPIDs other than 0x8100. Well known and standard tags include:
- 0x8100 customer VLAN
- 0x88a8 service VLAN tag used in provider bridging
- 0x9100 service VLAN tag used in provider bridging (common, but not standardized)
Other non-standard TPID values may also be configured for interoperability with legacy equipment or non-standard systems. Values range from 0x600 (1536) through 0xFFFF (65535).
Non-default TPID values are most commonly used for provider bridging on a network-to-network interface.
VLAN Routing
Each VLAN can be associated with a switch virtual interface (SVI), also called a VLAN interface. The VLAN interface functions in a routed network (Layer 3) with an assigned IP subnet address. Connecting different VLANs requires Layer 3 networking.
VLAN Interfaces
A switched virtual interface (SVI) connects to the VLAN segment on the switch to provide layer 3 processing for packets from the VLAN. An SVI can be activated only after it is connected to a VLAN. SVIs are typically configured for a VLAN to a default gateway for a subnet to facilitate traffic routing with other subnets.
In a layer 3 network, each VLAN SVI is associated with an IP subnet, with all stations in the subnet members of the VLAN. Traffic between different VLANs is routed when IP routing is enabled.
Internal VLANs
A routed port is an Ethernet or port channel interface that functions as a layer 3 interface. Routed ports do not bridge frames nor switch VLAN traffic. Routed ports have IP addresses assigned to them and packets are routed directly to and from the port.
The switch allocates an internal VLAN for an interface when it is configured as a routed port. The internal VLAN is assigned a previously unused VLAN ID. The switch prohibits the subsequent configuration of VLANs and VLAN interfaces with IDs corresponding to allocated internal VLANs.
VLAN Mapping
VLAN mapping allows you to map packets from one VLAN to another. The switchport vlan mapping command maps an arbitrary incoming VLAN tag to a particular bridging VLAN on the switch. VLAN mapping is configured on packets having a dot1q header (tagged frames) only. The mapping is applied on a trunk port and multiple mappings can exist under each trunk port.
To use VLAN mapping on a switched port, the port must be configured as a trunk port using the switchport mode command.
Platform Compatibility
- DCS-7500E
- DCS-7280E
Examples
- These commands map ingress packets on an Ethernet interface 3.
switch(config)#interface Ethernet 3 switch(config-if-Et3)#switchport vlan mapping in 11 200
- These commands map egress packets on an Ethernet interface 5.
switch(config)#interface Ethernet 5 switch(config-if-Et5)#switchport vlan mapping out 300 12
- These commands map multiple packets under a trunk port on an Ethernet interface 3.
switch(config)#interface Ethernet 3 switch(config-if-Et3)#switchport mode trunk switch(config-if-Et3)#switchport vlan mapping 10 100 switch(config-if-Et3)#switchport vlan mapping in 11 200 switch(config-if-Et3)#switchport vlan mapping out 300 12
VLAN Translation
VLAN translation allows you to map packets from one VLAN to another. This can be carried out only on packets having a dot1q header (tagged frames). The translation rewrites the VID field (VLAN ID) in dot1q headers on packets passing through a switched port without changing any other fields.
VLAN translation also supports the ability to translate packets with a dot1q header to the internal VLAN for a routed port. The VLAN in the incoming packets is mapped to the internal VLAN of the routed port and packets egressing the routed port are encapsulated with a dot1q header for the specified VLAN. For egress packets, no priority information is added to the dot1q header and the priority from the incoming encapsulation will be retained.
When configuring the VLAN translation mode, consider the following:
- VLAN translation is only supported for tagged packets.
- BPDUs from STP, LLDP and other protocols are not affected by this mapping.
- VLAN translation is not applicable for access ports.
- Untagged packets entering the switch on the trunk native VLAN are not mapped.
- TPID and VLAN priority does not get re-written during the translation.
VLAN Configuration Procedures
These sections describe basic VLAN configuration tasks.
Creating and Configuring VLANs
The CLI provides two methods of creating VLANs.
- Explicitly through the vlan command.
- Implicitly through the switchport access vlan command.
The switchport access vlan command generates a warning message when it creates a VLAN.
To create a VLAN, use the vlan command in global configuration mode. Valid VLAN numbers range between 1 and 4094. To create multiple VLANs, specify a range of VLAN numbers.
To edit an existing VLAN, enter the vlan command with the number of the existing VLAN.
Example
This command creates VLAN 45 and enters VLAN configuration mode for the new VLAN.
switch(config)#vlan 45
switch(config-vlan-45)#
Use the name (VLAN configuration mode) command to assign a name to a VLAN.
Example
These commands assign the name Marketing to VLAN 45.
switch(config)#vlan 45
switch(config-vlan-45)#name Marketing
switch(config-vlan-45)#show vlan 45
VLAN Name StatusPorts
---- -------------------------------- --------- -------
45 Marketing active Et1
switch(config-vlan-45)#
To change a VLAN’s state, use the state command in VLAN configuration mode.
Examples
- These commands suspend VLAN 45. VLAN traffic is blocked on all switch
ports.
switch(config)#vlan 45 switch(config-vlan-45)#state suspend switch(config-vlan-45)#show vlan 45 VLAN Name StatusPorts ---- -------------------------------- --------- ------ 45 Marketing suspended switch(config-vlan-45)#
- These commands activate VLAN
45.
switch(config)#vlan 45 switch(config-vlan-45)#state active switch(config-vlan-45)#show vlan 45 VLAN Name StatusPorts ---- -------------------------------- --------- ------ 45 MarketingactiveEt1 switch(config-vlan-45)#
VLAN Policy
The VLAN policy configuration command enables a switch to configure a VLAN policy when it receives a packet with unknown destination MAC address on a VLAN. The mac address forwarding command provides three options to configure a VLAN policy:
- Flood the Layer 2 miss packets on the VLAN
- Drop the Layer 2 miss packets
- Log the Layer 2 miss packets to the CPU (while still flooding them on the VLAN)
The default behavior is to flood the L2 miss packets on all ports of the VLAN.
VLAN policy configuration is supported on the Arista 7010, 7050 (excluding 7050SX3-48YC12, 7050CX3-32S, 7050QX2-32S, 7050SX2-72Q, 7050SX2-128, 7050TX2-128), 7060, 7250, and the 7300 series platforms.
VLAN policy is not supported in the following cases:
- STP, LLDP, and LACP packets
- VLAN policy configurations on VXLAN-enabled VLAN
- On a VLAN if IGMP snooping is configured with Multicast miss action is set to drop, then all multicast packets received on that VLAN are dropped.
Examples
- These commands create a VLAN 333 and then set the unicast
policy to ‘drop’ and the multicast policy to ‘log’ for the specific VLAN
333.
switch(config)#vlan 333 switch(config-vlan-333)#mac address forwarding unicast miss action drop switch(config-vlan-333)# switch(config-vlan-333)#mac address forwarding multicast miss action log
- These commands display the VLAN policy that was defined when VLAN 333 is
created.
switch(config)#show vlan 333 mac address forwarding VLANUcMissActionMcMissAction ---------------------------- 333flood flood
- These commands display the VLAN policy type that was defined when VLAN
333 is configured with the ‘drop’ unicast policy and the ‘log’ multicast
policy.
switch(config)#show vlan 333 mac address forwarding VLANUcMissActionMcMissAction ---------------------------- 333droplog switch(config)#show vlan mac address forwarding VLANUcMissActionMcMissAction ---------------------------- 1flood flood 333droplog
Configuring VLAN Switching
The following describe the configuration of VLAN ports.
Access Ports
Access ports carry traffic for one VLAN, as designated by a switchport access vlan command. Access ports associate untagged frames with the access VLAN. Tagged frames received by the interface are dropped unless they are tagged with the access VLAN.
To configure an interface group as an access port, use the switchport mode command.
Example
These commands configure Ethernet interface 1 as an access port.
switch(config)#interface ethernet 1
switch(config-if-Et1)#switchport mode access
switch(config-if-Et1)#
To specify the port’s access VLAN, use the switchport access vlan command.
Examples
-
These commands configure VLAN 15 as the access VLAN for Ethernet interface 5.
switch(config)#interface ethernet 5 switch(config-if-Et5)#switchport access vlan 15 switch(config-if-Et5)#
-
These commands configure Ethernet interface 1 through 3 as access ports that process untagged frames as VLAN 5 traffic.
switch(config)#interface Ethernet 1-3 switch(config-if-Et1-3)#switchport mode access switch(config-if-Et1-3)#switchport access vlan 5 switch(config-if-Et1-3)#show interfaces ethernet 1-3 vlans Port Untagged Tagged Et1None 23,25 Et218 - Et3None 14 switch(config-if-Et1-3)#
Trunk Ports
Trunk ports carry traffic for multiple VLANs. Messages use tagged frames to specify the VLAN for which trunk ports process traffic.
- The vlan trunk list specifies the VLANs for which the port handles tagged frames. The port drops any packets tagged for VLANs not in the VLAN list.
- The native vlan is the VLAN where the port switches untagged frames.
To configure an interface group as a trunk port, use the switchport mode command.
Example
These commands configure Ethernet interface 8 as a trunk port.
switch(config)#interface ethernet 8
switch(config-if-Et8)#switchport mode trunk
switch(config-if-Et8)#
By default all VLANs are permitted on a port configured with ‘switchport mode trunk’. To limit the port’s VLAN trunk list, use the switchport trunk allowed vlan command. Only VLANs in the allowed list will be permitted.
Examples
- These commands configure VLAN 15, 20, 21, 22, 40, and 75 as the explicitly
permitted VLAN trunk list for Ethernet interface
12-16.
switch(config)#interface ethernet 12-16 switch(config-if-Et12-16)#switchport trunk allowed vlan 15,20-22,40,75 switch(config-if-Et12-16)#
- These commands explicitly permit VLAN 100 through 120 to the VLAN trunk list for
Ethernet interface
14.
switch(config)#interface ethernet 14 switch(config-if-Et14)#switchport trunk allowed vlan add 100-120 switch(config-if-Et14)#
To specify the port’s native VLAN, use the switchport trunk native vlan command.
Example
These commands configure VLAN 12 as the native VLAN trunk for Ethernet interface 10.
switch(config)#interface ethernet 10
switch(config-if-Et10)#switchport trunk native vlan 12
switch(config-if-Et10)#
By default, ports send native VLAN traffic with untagged frames. The switchport trunk native vlan command can also configure the port to send native VLAN traffic with tag frames.
Examples
- These commands configure Ethernet interface 10 to send native
VLAN traffic as
tagged.
switch(config)#interface ethernet 10 switch(config-if-Et10)#switchport trunk native vlan tag switch(config-if-Et10)#
- These commands configure Ethernet interface 12 as a trunk with
VLAN 15 as the native VLAN. The port’s trunk list includes all VLANs except
201-300.
switch(config)#interface ethernet 12 switch(config-if-Et12)#switchport mode trunk switch(config-if-Et12)#switchport trunk native vlan 15 switch(config-if-Et12)#switchport trunk allowed vlan except 201-300 switch(config-if-Et12)#
Example
Assume that all ports on the switch are configured with switchport mode trunk similar to ethernet 1 and 2 shown below:
!
interface ethernet 1
switchport mode trunk
!
interface ethernet 2
switchport mode trunk
!
Further assume that VLAN 30 is not configured as part of a trunk group
switch#show vlan
VLANName StatusPorts
----- -------------------------------- --------- ----------
1 defaultactiveEt1, Et2
30vlan30 activeEt1, Et2
Now configure VLAN 30 as part of trunk group 30:
switch(config)#vlan 30
switch(config-vlan-30)#trunk group 30
This updates the VLAN membership for VLAN 30.
switch#show vlan
VLANName StatusPorts
----- -------------------------------- --------- -----------
1 defaultactiveEt1, Et2
30vlan30 active
To permit VLAN 30 on Et1 you need to associate the interface with the trunk group as follows:
switch(config-if-Et1)#switchport trunk group 30
Now we see Et1 included in the vlan 30 list
switch#show vlan
VLANName StatusPorts
----- -------------------------------- --------- ----------
1 defaultactiveEt1, Et2
30vlan30 activeEt1
The trunk group command is not additive to the allowed vlan command
interface ethernet 1
switchport mode trunk
switchport trunk allowed vlan 10
switchport trunk group trunk30
Vlan 30 will not be permitted on the interface as it is not listed in the allowed
vlan list.
Dot1q Tunnel Ports
Dot1q (802.1Q) is a tunneling protocol that encapsulates traffic from multiple customer (c-tag) VLANs in an additional single outer service provider (s-tag) VLAN for transit across a larger network structure that includes traffic from all customers. Tunneling eliminates the service provider requirement that every VLAN be configured from multiple customers, avoiding overlapping address space issues.
Tunneling preserves the inner VLANs through the tunneled network; these inner VLANs are ignored by intermediate devices that make forwarding decisions based only on the outermost VLAN tag (S-Tag)
A dot1q-tunnel port sits at the edge of the tunneled network. Unlike regular access ports, a dot1q-tunnel port does not drop traffic that arrives with 802.1Q tags in place; it ignores existing 802.1Q information and associates arriving traffic (with or without 802.1Q headers) with a new tunnel VLAN ID.
Packets arriving at a tunnel port are encapsulated with an additional 802.1Q tag that can be trunked between multiple devices like any traditional VLAN. When exiting a dot1-tunnel port, the S-Tag is removed to revert the customer traffic to its original tagged or untagged state.
To configure an interface group as a dot1q tunnel port, use the switchport mode command.
Example
- These commands configure Ethernet interface 12 as a dot1q tunnel
port.
switch(config)# interface ethernet 12 switch(config-if-Et12)# switchport mode dot1q-tunnel switch(config-if-Et12)#
To specify the dot1q-tunnel port’s access VLAN, use the switchport access vlan command. The port then handles all inbound traffic as untagged VLAN traffic.
Example
- These commands configure VLAN 60 as the access VLAN for Ethernet interface
12.
switch(config)#interface ethernet 12 switch(config-if-Et12)#switchport access vlan 60 switch(config-if-Et12)#
TPID Configuration
The default tag protocol identifier (TPID, also called dot1q ethertype) on all switch ports is 0x8100. To configure a different TPID on a port, use the switchport dot1q ethertype command. This feature is available only on 7280E and 7500E platforms.
Example
In this provider bridging example, Ethernet interface 1 is the user network interface and Ethernet interface 2 is the network-to-network interface. These commands configure dot1q tunneling on Ethernet interface 1 and set the TPID of Ethernet interface 2 to 0x9100.
switch(config)#interface ethernet 1
switch(config-if-Et1)#switchport mode dot1q-tunnel
switch(config-if-Et1)#interface ethernet 2
switch(config-if-Et2)#switchport mode trunk
switch(config-if-Et2)#switchport dot1q ethertype 0x9100
switch(config-if-Et2)#
In the above configuration, packets from Et1 to Et2 will undergo dot1q-tunneling (stacking of an additional dot1q tag), with an outer TPID of 0x9100 at egress, while packets with outer TPID 0x9100 going from Et2 to Et1 will have the outer tag removed at egress.
Layer 2 802.1Q Encapsulation
Layer 2 traffic encapsulation is enabled on the configuration mode interface for a specified VLAN through l2-protocol encapsulation dot1q vlan.
Example
These commands enable traffic encapsulation for VLAN 200 traffic passing through Ethernet interface 5/2.
switch(config)#interface ethernet 5/2
switch(config-if-Et5/2)#l2-protocol encapsulation dot1q vlan 200
Port VLAN Scaling on DCS-7160
Port VLAN scaling allows the user to configure a subset of ports in the scale mode. The switchport vlan forwarding command forwards packets between the ports belonging to VLAN in the interface configuration mode. Port-VLAN table is used for storing the configuration on a per port/VLAN combination. The scaling configuration is applicable on a per-port basis and supports a maximum of 128 ports.
Example
- This command enables VLAN scaling on a port with an Ethernet interface
2.
switch# config terminal switch(config)# interface Ethernet 2 switch(config-if-Et2)# switchport vlan forwarding accept all
- This command disables VLAN scaling on a
port.
switch# config switch(config)# interface Ethernet 2 switch(config-if-Et2)# no switchport vlan forwarding accept all
Creating and Configuring VLAN Interfaces
The interface vlan command places the switch in VLAN-interface configuration mode for modifying an SVI. An SVI provides a management address point and Layer 3 processing for packets from all VLAN ports.
Example
This command enters VLAN-interface configuration mode for VLAN 12. The command also creates VLAN 12 interface if it was not previously created.
switch#config t
switch(config)#interface vlan 12
switch(config-if-Vl12)#
Allocating Internal VLANs
The vlan internal order command specifies the VLANs that the switch allocates as internal VLANs when configuring routed ports and the order of their allocation. By default, the switch allocates VLANs in ascending order. The default allocation range is between VLAN 1006 and VLAN 4094.
The no switchport command converts an Ethernet or port channel interface into a routed port, disabling layer 2 switching for the interface.
Examples
- This command configures the switch to allocate internal VLANs in ascending order
starting with
1006.
switch(config)#vlan internal order ascending switch(config)#
- This command configures the switch to allocate internal VLANs in descending order
starting with
4094.
switch(config)#vlan internal order descending switch(config)#
- This command configures the switch to allocate internal VLANs in descending order
from 4094 through
4000.
switch(config)#vlan internal order descending range 4000 4094 switch(config)#
VLAN Mapping
VLAN mapping allows you to map packets from one VLAN to another. The switchport vlan mapping command maps an arbitrary incoming VLAN tag to a particular bridging VLAN on the switch. VLAN mapping is configured on packets having a dot1q header (tagged frames) only. The mapping is applied on a trunk port and multiple mappings can exist under each trunk port.
To use VLAN mapping on a switched port, the port must be configured as a trunk port using the switchport mode command.
Platform Compatibility
- DCS-7500E
- DCS-7280E
Examples
- These commands map ingress packets on an Ethernet interface 3.
switch(config)#interface Ethernet 3 switch(config-if-Et3)#switchport vlan mapping in 11 200
- These commands map egress packets on an Ethernet interface 5.
switch(config)#interface Ethernet 5 switch(config-if-Et5)#switchport vlan mapping out 300 12
- These commands map multiple packets under a trunk port on an Ethernet interface 3.
switch(config)#interface Ethernet 3 switch(config-if-Et3)#switchport mode trunk switch(config-if-Et3)#switchport vlan mapping 10 100 switch(config-if-Et3)#switchport vlan mapping in 11 200 switch(config-if-Et3)#switchport vlan mapping out 300 12
Dual Tag VLAN Mapping
Dual tag VLAN mapping allows mapping between outer or inner VID of double tagged packet and a bridging VLAN. At ingress, a pair of VLAN IDs are mapped to a bridging VLAN and at egress, the bridging VLAN is mapped to a pair of VLAN IDs.
Examples
- These commands map a pair of VLAN IDs on an Ethernet interface
3/1.
switch(config)# interface Ethernet 3/1 switch(config-if-Et3/1)# switchport vlan mapping 1000 inner 100 200
VLAN Translation
VLAN translation allows you to map packets from one VLAN to another. This can be carried out only on packets having a dot1q header (tagged frames). The translation rewrites the VID field (VLAN ID) in dot1q headers on packets passing through a switched port without changing any other fields.
VLAN translation also supports the ability to translate packets with a dot1q header to the internal VLAN for a routed port. The VLAN in the incoming packets is mapped to the internal VLAN of the routed port and packets egressing the routed port are encapsulated with a dot1q header for the specified VLAN. For egress packets, no priority information is added to the dot1q header and the priority from the incoming encapsulation will be retained.
When configuring the VLAN translation mode, consider the following:
- VLAN translation is only supported for tagged packets.
- BPDUs from STP, LLDP and other protocols are not affected by this mapping.
- VLAN translation is not applicable for access ports.
- Untagged packets entering the switch on the trunk native VLAN are not mapped.
- TPID and VLAN priority does not get re-written during the translation.
Per-port VLAN Translation on Switched Ports
The switchport vlan translation command allows translation of the VLAN tag of traffic entering or exiting a switched port.
To use VLAN translation on a switched port, the port must be configured as a trunk port using the switchport mode command.
Example
This command configures Ethernet interface 5 as a trunk port.
switch(config)#interface ethernet 5
switch(config-if-Et5)#switchport mode trunk
switch(config-if-Et5)#
By default, the translation is bidirectional: packets ingressing an interface through VLAN A are internally mapped to VLAN B; VLAN B packets egressing the same interface are mapped to VLAN A.
Examples
- These commands map Ethernet interface 5 traffic with dot1q tag
50 to bridging VLAN
60.
switch(config)#interface ethernet 5 switch(config-if-Et5)#switchport vlan translation 50 60 switch(config-if-Et5)#
- These commands provides multiple 1:1 VLAN mappings under an interface.
switch(config)#interface ethernet 5 switch(config-if-Et5)#switchport vlan translation 50 60 switch(config-if-Et5)#switchport vlan translation 61 71 switch(config-if-Et5)#switchport vlan translation 62 72 switch(config-if-Et5)#
- These commands translate only incoming
packets.
switch(config)#interface ethernet 5 switch(config-if-Et5)#switchport vlan translation in 50 60 switch(config-if-Et5)#
- These commands translate only egress
packets.
switch(config)#interface ethernet 5 switch(config-if-Et5)#switchport vlan translation out 60 50 switch(config-if-Et5)#
Per-port VLAN Translation on Routed Ports
On routed ports, the encapsulation dot1q vlan command (permitted only on routed ports) configures the VLAN on the interface to act as the native VLAN. This command will map packets ingressing with the specified VLAN ID to the internal VLAN ID of the routed port. All traffic egressing out of the routed port will be tagged with the VLAN ID specified in the command.
Examples
These commands translate between VLAN 50 and the internal VLAN for Ethernet interface 5 (a routed port).
switch(config)#interface ethernet 5
switch(config-if-Et5)#no switchport
switch(config-if-Et5)#encapsulation dot1q vlan 50
switch(config-if-Et5)#
Double VLAN Translation
VLAN translation allows you to map packets from one VLAN to another. The translation rewrites the VLAN ID (VID) field in dot1q headers on packets passing through a switched port without changing any other fields. By default, the translation is bidirectional.
Thecommand allows translation of the VLAN traffic entering or exiting a switched port.
Thecommand allows translation between outer or inner VLAN ID of double tagged packet and a bridging VLAN. At the ingress, a pair of VLAN IDs are mapped to a bridging VLAN while at the egress, the bridging VLAN is mapped to a pair of VLAN IDs.
Platform Compatibility
- DCS-7500E
- DCS-7280E
Examples
- These commands map inner and outer VLAN IDs on an Ethernet interface
1.
switch(config)#interface Ethernet 1 switch(config-if-Et1)#switchport vlan mapping 10 inner 50 100 switch(config-if-Et1)#switchport vlan mapping in 20 inner 60 100 switch(config-if-Et1)#switchport vlan mapping out 200 30 inner 40 switch(config-if-Et1)#switchport vlan mapping 70 300
- These commands map Ethernet interface 5 traffic with dot1q tag
50 to bridging VLAN
60.
switch(config)#interface ethernet 5 switch(config-if-Et5)#switchport vlan translation 50 60 switch(config-if-Et5)#
VLAN Configuration commands
Global VLAN Configuration commands
VLAN Configuration Mode commands
Layer 2 Interface (Ethernet and Port Channel) Configuration commands
VLAN Interface Configuration Mode commands
Show commands
- show dot1q-tunnel
- show interfaces switchport
- show interfaces switchport backup-link
- show interfaces switchport vlan mapping
- show interfaces trunk
- show interfaces vlans
- show pvlan mapping interfaces
- show vlan
- show vlan brief count
- show vlan dynamic
- show vlan internal allocation policy
- show vlan internal usage
- show vlan trunk group
vlan internal order
The vlan internal order command specifies the range that the switch can allocate as internal VLANs when configuring routed ports and the order of their allocation. By default, the switch allocates VLANs in ascending order from VLAN 1006 to VLAN 4094.
The no vlan internal order and default vlan internal order commands revert the policy to its default.
Command Mode
Global Configuration
Command Syntax
vlan internal order DIRECTION [RANGE_VLAN]
no vlan internal order
default vlan internal order
Parameters
- DIRECTION VLAN allocation number direction.
Options include:
- ascending allocates internal VLANs from lower VLAN bound to upper VLAN bound.
- descending allocates internal VLAN from upper VLAN bound to lower VLAN bound.
- RANGE_VLAN allocation range. Options
include:
- <no parameter> 1006 (lower bound) to 4094 (upper bound).
- range, lower, upper specifies lower bound (lower) and upper bound (upper).
Examples
- This command configures the switch to allocate internal VLANS
from 3000 through
3999.
switch(config)#vlan internal order ascending range 3000 3999 switch(config)#
- This command configures the switch to allocate internal VLANS
from 4094 through
1006.
switch(config)#vlan internal order descending switch(config)#
- This command configures the switch to allocate internal VLANS
from 4094 down through 4000.
switch(config)#vlan internal order descending range 4000 4094 switch(config)#
- This command reverts the allocation policy to its default
(ascending, between 1006 and
4094).
switch(config)#no vlan internal order switch(config)#
vlan
The vlan command places the switch in VLAN configuration mode to configure a set of virtual LANs. The command creates the specified VLANs if they do not exist prior to issuing the command. A VLAN that is in use as an internal VLAN may not be created or configured. The switch rejects any vlan command that specifies an internal VLAN ID.
The default vlan and no vlan commands removes the VLAN statements from running-config for the specified VLANs.
The exit command returns the switch to global configuration mode.
Command Mode
Global Configuration
Command Syntax
vlan vlan_range
no vlan vlan_range
default vlan vlan_range
Parameters
- vlan_range VLAN list.
Formats include a name, number, number range, or comma-delimited list of numbers and ranges.
commands Available in VLAN configuration mode
Guidelines
In mlag configurations, VLANs operate as follows:
- The VLAN must be configured identically on both mlag peer switches.
- The port-specific bridging configuration originates on the switch where the port is physically located. This configuration includes the switchport access VLAN, switchport mode (trunk or access), trunk-allowed VLANs, the trunk native VLAN, and the switchport trunk groups.
Example
This command creates VLAN 49 and enters VLAN configuration mode for the new VLAN:
switch(config)#vlan 49
switch(config-vlan-49)#
autostate
When autostate is enabled, the VLAN interface will be up when:
- the corresponding VLAN exists and is in the active state.
- one or more layer 2 ports in the VLAN are up and in spanning-tree forwarding state.
- the VLAN interface exists and is not in a shutdown state.
Autostate is enabled by default. When autostate is disabled, the VLAN interface is forced to be active.
- The no autostate command disables autostate on the configuration mode interface. The no autostate command is stored to running-config.
- The autostate command enables the autostate function on the configuration mode VLAN SVI by removing the corresponding no autostate statement from running-config.
-
The default autostate command restores the autostate default state of enabled by removing the corresponding no autostate statement from running-config.
Command Mode
Interface-VLAN Configuration
Command Syntax
autostate
no autostate
default autostate
Guidelines
Autostate should be disabled on SVIs configured as an mlag local interface.
Examples
-
These commands disable autostate on VLAN 100.
switch(config)#interface vlan 100 switch(config-if-Vl100)#no autostate switch(config-if-Vl100)#
-
These commands enable autostate on VLAN 100.
switch(config)#interface vlan 100 switch(config-if-Vl100)#autostate switch(config-if-Vl100)#
encapsulation dot1q vlan
In the configuration mode for an Ethernet or port channel interface, the encapsulation dot1q vlan translates packets with a dot1q header to the internal VLAN for a routed port. The VLAN in the incoming packets is mapped to the internal VLAN of the routed port, and packets egressing the routed port are encapsulated with a dot1q header for the specified VLAN. For egress packets, no priority information is added to the dot1q header and the priority from the incoming encapsulation will be retained.
Subinterface VLAN AssignmentWhen used in the configuration mode for an Ethernet or port channel subinterface, however, the encapsulation dot1q vlan command assigns a dot1q tag to the subinterface. Traffic ingressing on the parent interface with that dot1q tag will then be sent to the configured subinterface. See Subinterfaces and Subinterface Configuration for details.
The no encapsulation dot1q vlan and default encapsulation dot1q vlan commands restore the default VLAN to the configuration mode interface by removing the corresponding encapsulation dot1q vlan command from running-config.
Command Mode
Interface-Ethernet Configuration
Interface-port-channel Configuration
Subinterface-Ethernet Configuration
Subinterface-port-channel Configuration
Command Syntax
encapsulation dot1q vlan vlan_id
no encapsulation dot1q vlan
default encapsulation dot1q vlan
Parameters
vlan_id For VLAN translation, the ID of the external VLAN to be translated; for subinterface configuration, the VLAN of the subinterface. Values range from 1 to 4094.
Examples
- These commands translate between VLAN 50 and the internal VLAN
for Ethernet interface 5 (a routed
port).
switch(config)#interface ethernet 5 switch(config-if-Et5)#no switchport switch(config-if-Et5)#encapsulation dot1q vlan 50 switch(config-if-Et5)#
- These commands assign packets ingressing on Ethernet interface
1/1 with VLAN ID 100 to Ethernet subinterface
1/1.1.
switch(config)#interface ethernet1/1.1 switch(config-if-Et1/1.1)#no switchport switch(config-if-Et1/1.1)#encapsulation dot1q vlan 100 switch(config-if-Et1/1.1)#
interface vlan
The interface vlan command places the switch in VLAN-interface configuration mode for modifying parameters of the switch virtual interface (SVI). An SVI provides Layer 3 processing for packets from all ports associated with the VLAN. There is no physical interface for the VLAN.
When entering configuration mode to modify existing SVIs, the command can specify multiple interfaces. The command creates an SVI if the specified interface does not exist prior to issuing the command. When creating an SVI, the command can only specify a single interface.
The no interface vlan command deletes the specified SVI interfaces from running-config. The default interface vlan commands remove all configuration statements for the specified SVI interfaces from running-config without deleting the interfaces.
Command Mode
Global Configuration
Command Syntax
interface vlan v_range
no interface vlan v_range
default interface vlan v_range
Parameter
- v_range VLAN interfaces (number, range, or comma-delimited list of numbers and ranges). VLAN number ranges from 1 to 4094.
Restrictions
Internal VLANs: A VLAN interface cannot be created or configured for internal VLAN IDs. The switch rejects any interface vlan command that specifies an internal VLAN ID.
Example
This example creates an SVI for VLAN 12:
switch#config
switch(config)#interface vlan 12
switch(config-if-Vl12)#
l2-protocol encapsulation dot1q vlan
The l2-protocol encapsulation dot1q vlan command enables Layer 2 802.1Q traffic encapsulation on the configuration mode interface for a specified VLAN. The default VLAN for all interfaces is VLAN 1.
The no l2-protocol encapsulation dot1q vlan and default l2-protocol encapsulation dot1q vlan commands disable the specified encapsulation on the configuration mode interface by removing the corresponding l2-protocol encapsulation dot1q vlan command from running-config.
Command Mode
Interface-Ethernet Configuration
Interface-Port-channel Configuration
Command Syntax
l2-protocol encapsulation dot1q vlan vlan_id
no l2-protocol encapsulation dot1q vlan
default l2-protocol encapsulation dot1q vlan
Parameters
-
vlan_id the ID of the native VLAN. Values range from 1 to 4094.
Example
These commands enable 802.1Q encapsulation of traffic on VLAN 200.
switch(config)#interface ethernet 5/2
switch(config-if-Et5/2)#l2-protocol encapsulation dot1q vlan 200
switch(s1)(config-if-Et5/2)#show active
interface Ethernet5/2
l2-protocol encapsulation dot1q vlan 200
switch(config-if-Et5/2)#
mac address forwarding
The mac address forwarding command enables a switch to configure a VLAN policy when it receives a packet with an unknown destination MAC address on a VLAN. The command provides three options to configure a VLAN policy:
- Flood the Layer 2 miss packets on the VLAN
- Drop the Layer 2 miss packets
- Log the Layer 2 miss packets to the CPU (while still flooding them on the VLAN)
The default state is to flood the L2 miss packets on all ports of the VLAN.
The show vlan command displays information about the VLAN policy that is being configured.
The no form and the default form of the command removes the previously configured VLAN policy on the VLAN.
Command Mode
VLAN Configuration
Command Syntax
mac address forwarding {unicast | multicast} miss action {drop | flood | log}
no mac address forwarding {unicast | multicast} miss action {drop | flood | log}
default mac address forwarding{unicast | multicast} miss action {drop | flood | log}
Parameters
- unicast the unicast type of transmission.
- multicast the multicast type of transmission.
- drop the selected packets are dropped.
- flood the selected packets are flooded in the specific VLAN.
- log the selected packets are sent to the CPU for logging purpose.
Guidelines
VLAN policy configuration is supported on the Arista 7010, 7050 (excluding 7050SX3-48YC12, 7050CX3-32S, 7050QX2-32S, 7050SX2-72Q, 7050SX2-128, 7050TX2-128), 7060, 7250, and the 7300 series platforms.
VLAN policy is not supported in the following cases:
- STP, LLDP, and LACP packets
- VLAN policy configurations on VXLAN-enabled VLAN
- On a VLAN if IGMP snooping is configured with Multicast miss action is set to drop, then all multicast packets received on that VLAN are dropped.
Examples
- These commands create a VLAN 333 and then set the unicast policy
to ‘drop’ and the multicast policy to ‘log’ for the specific VLAN
333.
switch(config)#vlan 333 switch(config-vlan-333)#mac address forwarding unicast miss action drop switch(config-vlan-333)# switch(config-vlan-333)#mac address forwarding multicast miss action log
- These commands display the VLAN policy that was defined when VLAN
333 is
created.
switch(config)#show vlan 333 mac address forwarding VLANUcMissActionMcMissAction ---------------------------- 333flood flood
- These commands display the VLAN policy type that was defined when
VLAN 333 is configured with the ‘drop’ unicast policy and the ‘log’ multicast
policy.
switch(config)#show vlan 333 mac address forwarding VLANUcMissActionMcMissAction ---------------------------- 333droplog switch(config)#show vlan mac address forwarding VLANUcMissActionMcMissAction ---------------------------- 1flood flood 333droplog
name (VLAN configuration mode)
The name command configures the VLAN name. The name can have up to 32 characters. The default name for VLAN 1 is default. The default name for all other VLANs is VLANxxxx, where xxxx is the VLAN number. The default name for VLAN 55 is VLAN0055. The show vlan command displays the VLAN name.
The name command accepts all characters except the space.
The no name and default name commands restore the default name by removing the name command from running-config.
Command Mode
VLAN Configuration
Command Syntax
name label_text
no name
default name
Parameters
-
label_text character string assigned to name attribute. Maximum length is 32 characters. The space character is not permitted in the name string.
Example
These commands assign corporate_100 as the name for VLAN 25, then displays the VLAN name.
switch(config)#vlan 25
switch(config-vlan-25)#name corporate_100
switch(config-vlan-25)#show vlan 25
VLANName StatusPorts
----- -------------------------------- --------- ---------
25corporate_100active
switch(config-vlan-25)#
pvlan mapping
The pvlan mapping command maps a switch virtual interface (SVI) available in the primary VLAN to the secondary VLAN or VLANs in the VLAN configuration mode. The show pvlan mapping interfaces command displays the list of mapped VLANs.
The no pvlan mapping and default pvlan mapping commands restore the default state of the private VLAN mapping.
Command Mode
VLAN Configuration
Command Syntax
pvlan mapping{add | remove | vlan ID}
no pvlan mapping{add | remove | vlan ID}
default pvlan mapping{add | remove | vlan ID}
Parameters
- add adding VLANs to the PVLAN mapping of the current VLAN interface.
- remove removing VLANs from the PVLAN mapping of the current VLAN interface.
- vlan ID The secondary VLAN IDs of the private VLAN mapping. The IDs range from 1 to 4094.
Related commands
Example
These commands assign a secondary VLAN ID of 50 to the primary VLAN.
switch(config)#vlan 25
switch(config-vlan-25)#pvlan mapping 50
switch(config-vlan-25)#
show dot1q-tunnel
The show dot1q-tunnel command displays the ports that are configured in dot1q-tunnel switching mode. The switchport mode command configures the switching mode for the configuration mode interface.
Command Mode
EXEC
Command Syntax
show dot1q-tunnel [INTERFACE]
Parameters
- INTERFACE Interface type and numbers. Options include:
- <no parameter> Display information for all interfaces.
- ethernet e_range Ethernet interface range specified by e_range.
- loopback l_range Loopback interface specified by l_range.
- management m_range Management interface range specified by m_range.
- port-channel p_range Port-Channel Interface range specified by p_range.
- vlan v_range VLAN interface range specified by v_range.
- vxlan vx_range VXLAN interface range specified by vx_range.
Valid range formats include number, number range, or comma-delimited list of numbers and ranges.
Example
This command displays the ports that are configured in dot1q-tunnel switching mode.
switch>show dot1q-tunnel
dot1q-tunnel mode LAN Port (s)
------------------------------
Po4
Po21
Po22
switch>
show interfaces switchport backup-link
The show interfaces switchport backup-link command displays interfaces that are configured as switchport backup pairs and the operational status of each interface. For each pair, the command displays the names, roles, status, and VLAN traffic of each interface.
Command Mode
EXEC
Command Syntax
show interfaces [INTERFACE] switchport backup-link
show interfaces switchport backup-link [module{Fabric f_num | Linecard lc_num |Supervisor svr_num| Switchcard |<1-2> | <3-6>}]
Parameters
- INTERFACE Interface type and numbers. Options include:
- <no parameter> Display information for all interfaces.
- ethernet e_range Ethernet interface range specified by e_range.
- loopback l_range Loopback interface specified by l_range.
- management m_range Management interface range specified by m_range.
- port-channel p_range Port-Channel Interface range specified by p_range.
- vlan v_range VLAN interface range specified by v_range.
Valid e_range, l_range, m_range, p_range, and v_range formats include number, number range, or comma-delimited list of numbers and ranges.
- module Displays interfaces of the
specified module. Options include:
- Fabric f_num Displays interfaces of the specified fabric module. Value ranges from 1 to 6.
- Linecard lc_num Displays interfaces of the specified linecard module. Value ranges from 3 to 6.
- Supervisor svr_num Displays interfaces of the specified supervisor module. Accepted values are 1 and 2.
- Switchcard Displays interfaces of switchcard modules.
- <1-2> Displays interfaces of the specified supervisor module.
- <3-6> Displays interfaces of the specified linecard module.
- State Operational status of the
interface. Values include:
- Up Spanning tree mode is backup, interface status is up.
- Down Spanning tree mode is backup, interface status is down.
- Inactive Configuration The spanning tree mode is not backup.
-
- Forwarding vlans VLANs forwarded by the interface. Depends on interface operation status and prefer option specified by the switchport backup command.
Example
- This command displays the configured switchport primary-backup
pairs.
switch>show interfaces switchport backup-link Switch backup interface pair: Ethernet3/17, Ethernet3/8 Primary Interface: Ethernet3/17 State:Inactive Configuration Backup Interface:Ethernet3/8State:Inactive Configuration Preemption delay: 0 milliseconds Mac move burst size: 0 Mac move burst interval: 20 milliseconds Mac move destination: ff:ff:ff:ff:ff:ff
- This command displays interfaces of the module for linecard
4.
switch(config)#show int switchport backup-link module Linecard 4 Switch backup interface pair: Ethernet4/19/1, Ethernet4/19/2 Primary Interface: Ethernet4/19/1 State:Inactive Configuration Backup Interface:Ethernet4/19/2 State:Inactive Configuration Preemption delay: 0 milliseconds Mac move burst size: 0 Mac move burst interval: 20 milliseconds Mac move destination: ff:ff:ff:ff:ff:ff
show interfaces switchport vlan mapping
The show interfaces switchport vlan mapping command displays mapping information of the configured VLANs in an interface mode.
Command Mode
EXEC
Command Syntax
show interfaces switchport vlan mapping
Examples
- This command displays mapping information of the configured VLAN
IDs.
switch#show interfaces switchport vlan mapping -------------- Ethernet3 Direction Direction Original VlanNew VlanStatusConfiguredActive -------------- --------- --------- ----------- ----------- 10 100 ActiveIn/OutIn/Out 11 200 ActiveInIn 30012ActiveOut Out
- This command displays dual tag mapping information of the configured VLAN
IDs.
switch(config)#show interfaces switchport vlan mapping -------------- Ethernet3/1 Direction Direction Outer Tag Inner Tag VLAN ID StatusConfiguredActive Dot1qTunnel ----------- ----------- --------- --------- ----------- ---------------------- 1000100 200 activeIn/OutIn/Out- 1001101 201 activeInIn- 1002102 202 activeOut Out-
- This command displays dual tag mapping information of the configured VLAN
IDs.
switch(config)#show interfaces switchport vlan mapping -------------- Ethernet1/1 Direction Direction Outer TagInner Tag VLAN ID StatusConfiguredActive ----------- ----------- --------- --------- ----------- ----------- 70- 300 ActiveIn/OutIn/Out 1050100 ActiveIn/OutIn/Out 2060100 ActiveInIn 3040200 ActiveOut Out
show interfaces switchport
The show interfaces switchport command displays the switching configuration and operational status of the specified ports.
Command Mode
EXEC
Command Syntax
show interfaces [INTERFACE] switchport
Parameters
- INTERFACE Interface type and numbers. Options include:
- <no parameter> Display the switching status for all interfaces.
- ethernet e_range Ethernet interface range specified by e_range.
- loopback l_range Loopback interface specified by l_range.
- management m_range Management interface range specified by m_range.
- port-channel p_range Port-Channel Interface range specified by p_range.
- vlan v_range VLAN interface range specified by v_range.
Valid e_range, l_range, m_range, p_range, and v_range formats include number, number range, or comma-delimited list of numbers and ranges.
Example
- This command displays the switching status for all
interfaces.
switch(config)#show interface switchport Default switchport mode: access Name: Et5/1 Switchport: Enabled Administrative Mode: static access Operational Mode: static access MAC Address Learning: enabled Access Mode VLAN: 1 (default) Trunking Native Mode VLAN: 1 (default) Administrative Native VLAN tagging: disabled Trunking VLANs Enabled: ALL Static Trunk Groups: Dynamic Trunk Groups: Name: Et5/2 Switchport: Enabled Administrative Mode: static access Operational Mode: static access MAC Address Learning: enabled Access Mode VLAN: 1 (default) Trunking Native Mode VLAN: 1 (default) Administrative Native VLAN tagging: disabled Trunking VLANs Enabled: ALL Static Trunk Groups: Dynamic Trunk Groups: [...] switch(config)#
- This command displays the switching status of port channel interfaces 21 and
22.
switch>show interface port-channel 21-22 switchport Name: Po21 Switchport: Enabled Administrative Mode: tunnel Operational Mode: tunnel Access Mode VLAN: 1 (inactive) Trunking Native Mode VLAN: 100 (VLAN0100) Administrative Native VLAN tagging: disabled Trunking VLANs Enabled: ALL Trunk Groups: foo Name: Po22 Switchport: Enabled Administrative Mode: tunnel Operational Mode: tunnel Access Mode VLAN: 1 (inactive) Trunking Native Mode VLAN: 1 (inactive) Administrative Native VLAN tagging: disabled Trunking VLANs Enabled: ALL Trunk Groups: switch>
- This command displays the configured status of VLAN scaling for the Ethernet
interface 2/1
port.
switch#show interface Ethernet 2/1 switchport Name: Ethernet 2/1 Switchport: Enabled Administrative Mode: trunk Operational Mode: trunk MAC Address Learning: enabled Dot1q ethertype/TPID: 0x8100 (active) Dot1q VLAN Tag: Allowed Access Mode VLAN: 1 (default) Trunking Native Mode VLAN: 1 (default) Administrative Native VLAN tagging: disabled Trunking VLANs Enabled: ALL Static Trunk Groups: Dynamic Trunk Groups: Source interface filtering: enabled VLAN forwarding mode: allConfiguredVlans switch>
show interfaces trunk
The show interfaces trunk command displays configuration and status information for interfaces configured in switchport trunk mode.
Command Mode
EXEC
Command Syntax
show interfaces [INTERFACE] trunk
Parameters
-
INTERFACE Interface type and numbers. Options include:
- <no parameter> Display information for all interfaces.
- ethernet e_range Ethernet interface range specified by e_range.
- management m_range Management interface range specified by m_range.
- port-channel p_range Port-Channel Interface range specified by p_range.
Valid e_range, m_range, and p_range formats include number, number range, or comma-delimited list of numbers and ranges.
Example
This command displays the trunk status for all interfaces configured in switchport trunk mode.
switch>show interfaces trunk
PortModeStatusNative vlan
Po1 trunk trunking1
Po2 trunk trunking1
PortVlans allowed
Po1 1-15
Po2 16-30
PortVlans allowed and active in management domain
Po1 1-10
Po2 21-30
PortVlans in spanning tree forwarding state
Po1 1-10
Po2 21-30
switch>
show interfaces vlans
The show interfaces vlans command displays a table that lists the VLANs that are carried by the specified interfaces. Interfaces that do not carry VLANs are not listed in the table. The table lists the untagged (native or access) and tagged VLANs for each interface.
Command Mode
EXEC
Command Syntax
show interfaces [INT_NAME] vlans
Parameters
-
INT_NAME Interface type and number. Values include
- ethernet e_num Ethernet interface specified by e_num.
- management m_num Management interface specified by m_num.
- port-channel p_num Port-Channel Interface specified by p_num.
Example
This command displays the VLANs carried by all L2 ports.
switch>show interfaces vlans
Port Untagged Tagged
Et93910 -
Et11 3912 -
Et16 500-
Et17 3908 -
Et18 3908 -
Po11101-102,500,721,3000,
Po2101-
Po43902 -
Po53903 -
Po63992 -
Po7661-
Po83911 -
show pvlan mapping interfaces
The show pvlan mapping interfaces command displays information about the private VLAN mapping interfaces.
Command Mode
EXEC
Command Syntax
show pvlan mapping interfaces
Example
- This command displays information about the private VLAN mapping
interfaces.
switch(config)#int vlan 50 switch(config-if-Vl50)#pvlan mapping 70 switch(config-if-Vl50)#show pvlan mapping interfaces InterfaceSecondary Vlans ------------------------ Vlan50 70
show vlan brief count
The show vlan brief count command displays the number of VLANs that are configured on the switch.
Command Mode
EXEC
Command Syntax
show vlan brief count
Example
This command displays the number of VLANs on the switch.
switch>show vlan brief count
Number of existing VLANs : 18
switch>
show vlan dynamic
The show vlan dynamic command displays the source and quantity of dynamic VLANs on the switch. Dynamic VLANs support VM Tracer monitoring sessions.
Command Mode
EXEC
Command Syntax
show vlan dynamic
Example
This command displays the source and quantity of dynamic VLANs on the switch.
switch>show vlan dynamic
Dynamic VLAN source VLANS
vmtracer-poc88
switch>
show vlan internal allocation policy
The show vlan internal allocation policy command displays the method the switch uses to allocate VLANs to routed ports. The vlan internal order command configures the allocation method.
The allocation method consists of two configurable components:
- range: the list of VLANs that are allocated to routed ports.
- direction: the direction by which VLANs are allocated (ascending or descending).
Command Mode
EXEC
Command Syntax
show vlan internal allocation policy
Example
This command displays the internal allocation policy.
switch>show vlan internal allocation policy
Internal VLAN Allocation Policy: ascending
Internal VLAN Allocation Range: 1006-4094
switch>
show vlan internal usage
The show vlan internal usage command shows the VLANs that are allocated as internal VLANs for routed ports.
A routed port is an Ethernet or port channel interface that is configured as a layer 3 interface. Routed ports do not bridge frames and are not members of any VLANs. Routed ports can have IP addresses assigned to them and packets are routed directly to and from the port.
When an interface is configured as a routed port, the switch allocates an SVI with a previously unused VLAN ID. The switch prohibits the configuration of VLANs with numbers corresponding to internal VLAN interfaces allocated to a routed port. VLAN interfaces corresponding to SVIs allocated to a routed port cannot be configured by VLAN interface configuration mode commands.
Command Mode
EXEC
Command Syntax
show vlan internal usage
Example
This command displays the VLANs that are allocated to routed ports.
switch>show vlan internal usage
1006Ethernet3
1007Ethernet4
switch>
show vlan trunk group
The show vlan trunk group command displays the trunk group membership of the specified VLANs.
Command Mode
EXEC
Command Syntax
show vlan [VLAN_LIST] trunk group
Parameters
- VLAN_LIST VLAN list. Options include:
- <no parameter> all VLANs.
- v_range VLANs specified by v_range.
- id v_range VLANs specified by v_range.
- name v_name VLANs specified by the VLAN name v_name.
- VLAN VLAN ID.
- Trunk Groups Trunk groups associated with the listed VLANs.
Example
This command displays the trunk group membership of all configured VLANs.
switch>show vlan trunk group
VLAN Trunk Groups
---- -------------------------------------
5
10 first_group
12
40 second_group
100third_group
101middle_group
102
200
switch>
show vlan
The show vlan command displays the VLAN ID, name, status, and member ports of all configured VLANs. The command only displays active ports by default; by specifying configured-ports, the command displays all ports that are members of a configured VLAN regardless of their activity status, including Ethernet ports that are members of a port channel.
Command Mode
EXEC
Command Syntax
show vlan [VLAN_LIST][PORT_ACTIVITY]
Parameters
- VLAN_LIST List of VLANs displayed by command. Options include:
- <no parameter> all VLANs.
- v_range VLANs specified by v_range.
- id v_range VLANs specified by v_range.
- name v_name VLANs specified by the VLAN name v_name.
v_range formats include number, number range, or comma-delimited list of numbers and ranges.
- PORT_ACTIVITY Ports listed in table.
Options include:
- <no parameter> table displays only active ports (same as active-configuration option).
- active-configuration table displays only active ports.
- configured-ports table displays all configured ports.
- VLAN The VLAN ID.
- Name The name of the VLAN.
- Status The status of the VLAN.
- Ports The ports that are members of the VLAN.
Examples
- This command displays status and ports of VLANs
1-1000.
switch> show vlan 1-1000 VLANName StatusPorts ----- ------------------------ --------- -------------- 1 defaultactivePo1 184 fet.arka activeCpu, Po1, Po2 262 mgq.net activePPo2, Po1 512 sant.testactiveCpu, Et16, Po1 821 ipv6.net activeCpu, Po1, Po7 switch>
- This command displays the list of all the member interfaces under
each
SVI.
switch#show vlan VLANName StatusPorts ----- ------------------------ --------- ------------------------------- 1 defaultactive 2148VLAN2148 activeCpu, Et1, Et26 2700VLAN2700 activeCpu, Et18
state
The state command configures the VLAN transmission state of the configuration mode VLAN.
- Active state: Ports forward VLAN traffic.
- Suspendstate: Ports block VLAN traffic.
The default transmission status is active.
The no state command restores the default VLAN transmission state to the configuration mode VLAN by removing the corresponding state command from running-config.
Command Mode
VLAN Configuration
Command Syntax
state OPERATION_STATE
no state
default state
Parameters
- OPERATION_STATE VLAN transmission state.
Options include:
- active VLAN traffic is forwarded
- suspend LAN traffic is blocked.
Example
These commands suspend VLAN traffic on VLANs 100-102.
switch(config)#vlan 100-102
switch(config-vlan-100-102)#state suspend
switch(config-vlan-100-102)#
switchport access vlan
The switchport access vlan command specifies the access VLAN of the configuration mode interface. Ethernet or port channel interfaces that are in access mode are members of only the access VLAN. Untagged frames that the interface receives are associated with the access VLAN. Frames tagged with the access VLAN are also associated with the access VLAN. The interface drops all other tagged frames that it receives. By default, VLAN 1 is the access VLAN of all Ethernet and port channel interfaces.
An interface's access mode is effective only when the interface is in access mode or dot1q-tunnel mode, as specified by the switchport mode command. Interfaces in dot1q-tunnel mode handle inbound traffic as untagged traffic and associate all traffic with the access VLAN. Interfaces configured to switchport trunk mode maintain and ignore existing switchport access commands.
The no switchport access vlan and default switchport access vlan commands restore VLAN 1 as the access VLAN of the configuration mode interface by removing the corresponding switchport access vlan statement from running-config.
Command Mode
Interface-Ethernet Configuration
Interface-Port-channel Configuration
Command Syntax
switchport access vlan v_num
no switchport access vlan
default switchport access vlan
Parameters
- v_num number of access VLAN. Value ranges from 1 to 4094. Default is 1.
Example
These commands assign VLAN 100 as the access VLAN to Ethernet interface 5.
switch(config)#interface ethernet 5
switch(config-if-Et5)#switchport access vlan 100
switch(config-if-Et5)#
switchport dot1q ethertype
The switchport dot1q ethertype command configures the tag protocol identifier (TPID, also known as a dot1q ethertype), of the configuration mode interface. By default, all switch ports use the standard TPID of 0x8100.
The no switchport dot1q ethertype and default switchport dot1q ethertype commands restore the TPID to 0x8100 by removing the corresponding switchport dot1q ethertype statement from running-config.
Command Mode
Interface-Ethernet Configuration
Command Syntax
switchport dot1q ethertype ethertype
no switchport dot1q ethertype
default switchport dot1q ethertype
Parameters
- ethertype ethertype number (TPID). Value ranges from 0x600 (1536) through 0xFFFF (65535), and can be entered in decimal or hexadecimal notation. Value is stored and displayed in hexadecimal form; the default value is 0x8100.
Example
These commands configure 0x9100 as the TPID of Ethernet interface 5.
switch(config)#interface ethernet 5
switch(config-if-Et5)#switchport dot1q ethertype 0x9100
switch(config-if-Et5)#
switchport mode
The switchport mode command specifies the switching mode of the configuration mode interface. The switch supports five switching modes: access, trunk, dot1q-tunnel, tap, and tool.
- Access switching mode: The interface is a member of one VLAN, called the access VLAN, as specified by the switchport access vlan command. Tagged frames received on the interface are dropped unless they are tagged with the access VLAN. Frames transmitted from the interface are always untagged.
- Trunk switching mode: The interface may be a member of multiple VLANs, as configured by the switchport trunk allowed vlan command. Untagged traffic is associated with the interface's native VLAN, as configured with the switchport trunk native vlan command.
- Dot1q-tunnel switching mode: The interface treats all inbound packets as untagged traffic and handles them as traffic of its access VLAN, as specified by the switchport access vlan command.
- Tap mode: The interface operates as a tap port. Tap ports receive traffic for replication on one or more tool ports.The interface may be a member of multiple VLANs, as configured by the switchport tap allowed vlan command. Untagged traffic is associated with the interface's native VLAN, as configured with the switchport tap native vlan command.
Tap ports are in STP forwarding state and prohibit egress traffic. MAC learning, control plane interaction and traps for inbound traffic are disabled.
- Tool mode: The interface operates as a tool port. Tool ports replicate traffic received by tap ports. The interface may be a member of multiple VLANs, as configured by the switchport tool allowed vlan command. MAC learning, control plane interaction and traps for inbound traffic are disabled.
Tool ports are in STP forwarding state and prohibit ingress traffic that uses port settings.
The status of switchport configured ports depends on the switch’s tap aggregation mode (which can be viewed by using the mode (tap-agg configuration mode) command):
- tap aggregation mode enabled: tap and tool ports are enabled. Switching ports are errdisabled.
- tap aggregation mode disabled: tap and tool ports are errdisabled. Switching ports are enabled.
The no switchport mode and default switchport mode commands return the configuration mode interface to its default setting as an access port by deleting the corresponding switchport mode command from running-config.
Command Mode
Interface-Ethernet Configuration
Interface-Port-channel Configuration
Command Syntax
switchport mode MODE_TYPE
no switchport mode
default switchport mode
Parameters
- MODE_TYPE switching mode of the configuration mode
interfaces. Options include:
- access access switching mode.
- dot1q-tunnel dot1q-tunnel switching mode.
- tap tap switching mode.
- tool tool switching mode.
- trunk trunk switching mode.
Restrictions
Dot1q-tunnel switching mode is not available on Petra platform switches.
Tap aggregation (tap and tool modes) is available on FM6000 and Arad platform switches.
Example
These commands configure Ethernet 4 interface as a trunk port.
switch(config)#interface ethernet 4
switch(config-if-Et4)#switchport mode trunk
switch(config-if-Et4)#
switchport trunk allowed vlan
The switchport trunk allowed vlan command creates or modifies the list of VLANs for which the configuration mode interface, in trunk mode, handles tagged traffic. By default, interfaces handle tagged traffic for all VLANs. Command settings persist in running-config without taking effect when the switch is in tap aggregation mode or the interface is not in trunk mode.
The no switchport trunk allowed vlan and default switchport trunk allowed vlan commands restore the trunk mode default allowed VLAN setting of all by removing the corresponding switchport trunk allowed vlan statement from running-config.
Command Mode
Interface-Ethernet Configuration
Interface-Port-channel Configuration
Command Syntax
switchport trunk allowed vlan EDIT_ACTION
no switchport trunk allowed vlan
default switchport trunk allowed vlan
Parameters
- EDIT_ACTION modifications to the VLAN list.
- v_range Creates VLAN list from v_range.
- add v_range Adds specified VLANs to current list.
- all VLAN list contains all VLANs.
- except v_range VLAN list contains all VLANs except those specified.
- none VLAN list is empty (no VLANs).
- remove v_range Removes specified VLANs from current list.
Valid v_range formats include number, range, or comma-delimited list of numbers and ranges.
Example
These commands create the trunk mode allowed VLAN list of 6-10 for Ethernet interface 14, then verifies the VLAN list.
switch(config)#interface ethernet 14
switch(config-if-Et14)#switchport trunk allowed vlan 6-10
switch(config-if-Et14)#show interfaces ethernet 14 switchport
Name: Et14
Switchport: Enabled
Administrative Mode: trunk
Operational Mode: trunk
Access Mode VLAN: 1 (inactive)
Trunking Native Mode VLAN: 1 (inactive)
Administrative Native VLAN tagging: disabled
Trunking VLANs Enabled: 6-10
Trunk Groups:
switch(config-if-Et14)#
switchport trunk group
The switchport trunk group command assigns the configuration mode interface to the specified trunk group. Trunk group ports handle traffic of the VLANs assigned to the group.
The no switchport trunk group and default switchport trunk group commands remove the configuration mode interface from the specified trunk group by deleting the corresponding statement from running-config. If the command does not specify a trunk group, the interface is removed from all trunk groups to which it is assigned.
Command Mode
Interface-Ethernet Configuration
Interface-Port-channel Configuration
Command Syntax
switchport trunk group [group_name]
no switchport trunk group [group_name]
default switchport trunk group [group_name]
Parameters
- group_name trunk group name.
Example
switch(config)#interface port-channel 4
switch(config-if-Po4)#switchport trunk group fe-1
switch(config-if-Po4)#
switchport trunk native vlan
The switchport trunk native vlan command specifies the trunk mode native VLAN for the configuration mode interface. Interfaces in trunk mode associate untagged frames with the native VLAN. Trunk mode interfaces can also be configured to drop untagged frames. The default native VLAN for all interfaces is VLAN 1.
The no switchport trunk native vlan and default switchport trunk native vlan commands restore VLAN 1 as the trunk mode native VLAN to the configuration mode interface by removing the corresponding switchport trunk native vlan command from running-config.
Command Mode
Interface-Ethernet Configuration
Interface-Port-channel Configuration
Command Syntax
switchport trunk native vlan VLAN_ID
no switchport trunk native vlan
default switchport trunk native vlan
Parameters
- VLAN_IDthe ID of the native VLAN. Options
include
- v_num VLAN number. Value ranges from 1 to 4094
- tag interface drops all untagged frames.
Example
These commands configure VLAN 100 as the native VLAN for port channel 21.
switch(config)#interface port-channel 21
switch(config-if-Po21)#switchport trunk native vlan 100
switch(config-if-Po21)#
switchport vlan forwarding
The switchport vlan forwarding command forwards packets between the ports belonging to VLAN in the interface configuration mode. The scaling configuration is applicable on a per-port basis. In the 7160 platform, the hardware uses a Port-VLAN table for storing the configuration on a per port/VLAN combination and supports a maximum of 128 ports.
Command Mode
Interface-Ethernet Configuration
Command Syntax
switchport vlan forwarding accept | all
Parameters
- accept accepts packets for VLAN
- all all VLANs
Example
This command forwards and accepts all the packets of VLAN of ethernet interface 2.
switch(config)#interface ethernet 2
switch(config-if-Et2)#switchport vlan forwarding accept all
switch(config-if-Et2)#
switchport vlan mapping
The switchport vlan mapping command allows you to map an arbitrary incoming VLAN tag to a particular bridging VLAN on the switch. The mapping is applied on a trunk port and multiple mappings can exist under each trunk port.
The no switchport vlan mapping and default switchport vlan mapping commands remove VLAN mapping by removing the corresponding switchport vlan mapping command from the running-config.
Command Mode
Interface-Ethernet Configuration
Interface-Port-channel Configuration
Command Syntax
switchport vlan mapping [in | out] incoming_vlanid destination_vlanid
no switchport vlan mapping [in | out]incoming_vlanid destination_vlanid
default switchport vlan mapping [in | out] incoming_vlanid destination_vlanid
Parameters
- in maps the specified VLAN ID for received traffic only.
- out maps the specified VLAN ID for transmitted traffic only.
- incoming_vlanid specifies the VLAN ID to be mapped. Value ranges from 1 to 4094.
- destination_vlanid specifies the destination VLAN ID. Value ranges from 1 to 4094.
Examples
- These commands map ingress packets of VLAN tag 11 with
VLAN 200 on an Ethernet interface
3.
switch(config)#interface Ethernet 3 switch(config-if-Et3)#switchport mode trunk switch(config-if-Et3)#switchport vlan mapping in 11 200
- These commands map egress packets of VLAN 300
with VLAN tag 12 on an Ethernet interface
5.
switch(config)#interface Ethernet 5 switch(config-if-Et5)#switchport mode trunk switch(config-if-Et5)#switchport vlan mapping out 300 12
- These commands map inner and outer VLAN IDs on an
Ethernet interface
1.
switch(config)#interface Ethernet 1 switch(config-if-Et1)#switchport vlan mapping 10 inner 50 100 switch(config-if-Et1)#switchport vlan mapping in 20 inner 60 100 switch(config-if-Et1)#switchport vlan mapping out 200 30 inner 40 switch(config-if-Et1)#switchport vlan mapping 70 300
switchport vlan translation
The switchport vlan translation command allows you to map packets from one VLAN to another using VLAN translation. This is carried out on packets having a dot1q header (tagged frames) only. The translation rewrites the VLAN ID (VID) field in dot1q headers on packets passing through a switched port without changing any other fields.
By default, the translation is bidirectional. The packets ingressing an interface through VLAN A are internally mapped to VLAN B; VLAN B packets egressing the same interface are mapped to VLAN A.
To use VLAN translation on a switched port, the port must be configured as a trunk port using the switchport mode command.
VLAN translation on routed ports is accomplished through the encapsulation dot1q vlan command.
The no switchport vlan translation and default switchport vlan translation commands remove VLAN mapping by removing the switchport vlan translation command from running-config.
Command Mode
Interface-Ethernet Configuration
Interface-Port-channel Configuration
Command Syntax
switchport vlan translation [DIRECTION]incoming_vlanid new_vlanid
no switchport vlan translation incoming_vlanid new_vlanid
no switchport vlan translation DIRECTION incoming_vlanid
default switchport vlan translation incoming_vlanid new_vlanid
default switchport vlan translation DIRECTION incoming_vlanid
Parameters
- DIRECTION direction of traffic to be translated.
- <no parameter> translates the specified VLAN IDs for transmitted and received traffic.
- in translates the specified VLAN IDs for received traffic only.
- out translates the specified VLAN IDs for transmitted traffic only.
- incoming_vlanid Enter the VLAN ID to be translated. Value ranges from 1 to 4094.
- new_vlanid The new VLAN ID or bridging VLAN ID that will be used internally. Value ranges from 1 to 4094.
- These commands translate only incoming packets, changing the VLAN ID to 2008 in the dot1q header of packets ingressing on VLAN 201.
switch(config)#interface ethernet 5 switch(config-if-Et5)#switchport vlan translation in 201 2008 switch(config-if-Et5)#
- These commands translate multiple VLAN mappings on an Ethernet
interface 5.
switch(config)#interface ethernet 5 switch(config-if-Et5)#switchport vlan translation 50 60 switch(config-if-Et5)#switchport vlan translation 61 71 switch(config-if-Et5)#switchport vlan translation 62 72 switch(config-if-Et5)#
trunk group
The trunk group command assigns the configuration mode VLAN to a specified trunk group.
A trunk group is the set of physical interfaces that comprise the trunk and the collection of VLANs whose traffic is carried on the trunk. The traffic of a VLAN that belongs to one or more trunk groups is carried only on ports that are members of trunk groups to which the VLAN belongs. Switchport commands specify the physical interfaces that carry trunk group traffic.
The no trunk group and default trunk group commands remove the configuration mode VLAN from the specified trunk group by removing the corresponding trunk group statement from running-config. If a trunk group is not specified, the commands remove the configuration mode VLAN from all trunk groups.
Command Mode
VLAN Configuration
Command Syntax
trunk group [name]
no trunk group [name]
default trunk group [name]
Parameters
- name a name representing the trunk group.
Example
switch(config)#vlan 49
switch(config-vlan-49)#trunk group mlagpeer
switch(config-vlan-49)#