- Written by Shyam Kota
- Posted on June 13, 2019
- Updated on August 4, 2025
- 20031 Views
The objective of Maintenance Mode on MLAG is to gracefully drain away the traffic (L2 and BGP) flowing through a switch
- Written by Saurabh Singhal
- Posted on July 17, 2025
- Updated on July 17, 2025
- 2695 Views
NIM-4S is a 4 port OCP 3.0 standard NIM card manufactured by Intel. The AWE-7230R-4TX-4S-F, AWE-5310-F, and AWE-7250R-16S-F, AWE-5510-F devices have 2 and 4 NIM (Network Interface Module) slots respectively. These devices now support NIM-4S cards.
- Written by Bhargav Jethwa
- Posted on June 27, 2024
- Updated on July 1, 2025
- 6620 Views
In some situations, packets received by an ASIC need to be redirected to the control plane: packets that have the destination address of the router or packets that need special handling from the CPU for example. The control plane cannot handle as many packets as the ASIC. A system that protects the control plane against DOS and prioritizes packets to send to the CPU is needed. This is accomplished by CoPP (control-plane policing). CoPP is already functioning, however, the CPU queues are statically allocated to a specific feature. If a feature is not used, the CPU queue statically allocated to the feature is not used either. This is a loss of resources.
- Written by Gaurav Chaudhari
- Posted on July 18, 2025
- Updated on July 18, 2025
- 2683 Views
If Dot1x Mac based authentication ( MBA ) is disabled, supplicant discovery is attempted by sending periodic multicast identity requests. These requests are transmitted at a fixed interval, which is 60 seconds. This transmission continues until a successful authentication of an EAPOL supplicant is achieved. With MBA enabled, supplicant discovery also relies on multicast identity requests. However, the transmission interval is set to 30 seconds and the transmission count is set to 3.
- Written by Saurav Arora
- Posted on July 15, 2025
- Updated on July 15, 2025
- 2786 Views
Destination based RTBH (remote triggered blackholing) is used on edge devices in a network to prevent DOS attack on a target network (IP/prefix) by blackholing/dropping the traffic destined towards this target. One of the ways to achieve this is through a trigger router sending a routing update for the prefix under attack to the edge routers configured for black hole filtering. The next-hop of such routing updates ends up getting resolved to a null/drop interface on the edge device, which results in blackholing all traffic destined towards this target network.
- Written by David Graham
- Posted on July 15, 2025
- Updated on July 15, 2025
- 2871 Views
When this feature is enabled, responses to gNMI subscribe requests contain the default values for YANG leafs if those leafs do not have any other value.
- Written by David Cronin
- Posted on March 3, 2022
- Updated on July 6, 2026
- 34930 Views
Routing control functions (RCF) is a language that can be used to express route filtering and attribute modification logic in a powerful and programmatic fashion. This document serves as a reference guide for Routing protocol attributes
- Written by David Cronin
- Posted on March 3, 2022
- Updated on July 6, 2026
- 21431 Views
Routing control functions (RCF) is a language that can be used to express route filtering and attribute modification logic in a powerful and programmatic fashion. This document serves as a reference guide for Bgp agent points of application:
- Written by Kalash Nainwal
- Posted on December 14, 2020
- Updated on July 13, 2026
- 19251 Views
RSVP-TE, the Resource Reservation Protocol (RSVP) for Traffic Engineering (TE), is used to distribute MPLS labels for steering traffic and reserving bandwidth. The Label Edge Router (LER) feature implements the headend functionality, i.e., RSVP-TE tunnels can originate at an LER which can steer traffic into the tunnel.
- Written by Martin Stigge
- Posted on October 22, 2018
- Updated on July 13, 2026
- 16565 Views
RSVP-TE applies the Resource Reservation Protocol (RSVP) for Traffic Engineering (TE), i.e., to distribute MPLS labels for steering traffic and reserving bandwidth.The EOS implementation supports:
- Written by Martin Stigge
- Posted on March 3, 2025
- Updated on December 17, 2025
- 4647 Views
RSVP-TE P2MP LER adds ingress and egress support for Point-to-Multipoint (P2MP) LSPs to be used in Multicast Virtual Private Network (MVPN) as an extension to the LSR support which adds transit support.
- Written by Jeevan Kamisetty
- Posted on November 4, 2020
- Updated on May 14, 2026
- 24611 Views
Network administrators require access to flow information that passes through various network elements, for the purpose of analyzing and monitoring their networks. This feature provides access to IP flow information by sampling traffic flows in ingress and/or egress directions on the interfaces on which it is configured. The samples are then used to create flow records, which are exported to the configured collectors in the IPFIX format. Egress Flow tracking is supported from EOS-4.29.0F on the DCS-7170B-64C series and supported on 7280, 7500 and 7800 series platforms from EOS-4.31.1"
- Written by Fangzheng
- Posted on March 16, 2026
- Updated on March 16, 2026
- 631 Views
This feature introduces a command to enable or disable USB ports, specifically designed to address strict security requirements in hardened environments. By restricting port functionality, administrators can prevent unauthorized access or booting from external USB storage.
- Written by Basil Saji
- Posted on January 17, 2022
- Updated on August 3, 2026
- 16065 Views
VXLAN UDP-ESP support allows the customer to encrypt traffic between two VXLAN VTEPs.
- Written by Sebastiano Borgione
- Posted on September 24, 2024
- Updated on August 13, 2026
- 5764 Views
The Dynamic Load Balancing (DLB) feature is currently supported in the DCS-7060 Arista switches in order to provide an alternative to the hash-based ECMP load balancing, which selects the next hop for routed packets using a static hash algorithm. DLB considers the state and quality of the port while assigning egress ports to packets, resulting in a more even flow. The state of each port member is determined by measuring the amount of data transmitted from a given port and the total number of packets enqueued to a given port.
- Written by Paul Miiller
- Posted on June 14, 2021
- Updated on February 5, 2026
- 30680 Views
The send support bundle feature adds a new CLI command which creates a ZIP file containing a useful set of logs and
- Written by Jared Dulmage
- Posted on July 5, 2024
- Updated on July 17, 2025
- 6594 Views
Priority-based flow control (PFC) buffer counters track ingress port buffer usage for each packet priority. This feature displays the high watermark buffer usage over two time intervals: a polling interval (by default 2 seconds) and the encompassing interval since the counters were cleared. The PFC buffer counter watermarks can be used to expose bursty and transient ingress buffer resource usage. High watermark values indicate congestion conditions that could explain packet loss.
- Written by Mayank Singh
- Posted on July 2, 2025
- Updated on July 2, 2025
- 2619 Views
The support for configurable dynamic authorization port for different clients has been added to proxy the radius dynamic authorization (CoA) requests. By default, all radius dynamic authorization requests are only proxied to clients at port 3799, which is configurable now.
- Written by Josh Pfosi
- Posted on June 11, 2019
- Updated on July 27, 2026
- 19739 Views
This feature adds support for CPU traffic policy capable of matching and acting on IP traffic which would otherwise hit the CPU. This policy is capable of permitting traffic from trusted sources, while rejecting untrusted traffic. It supports matching on a variety of IP packet header information such as DSCP, L4 port values, fragmentation bits, etc. as well as a number of actions such as permit, deny, and police. To prevent a malicious source from overloading the CPU, this traffic policy will take effect in the switching hardware, before the traffic is processed by the kernel. This feature provides a shorthand syntax for securing L3 protocol peers, in particular, BGP neighbors.
- Written by Deepanshu Shukla
- Posted on August 21, 2020
- Updated on January 12, 2026
- 23379 Views
This feature adds support for “Dynamic Load Balancing (DLB)” on Equal Cost Multi Path (ECMP) groups.
- Written by Brian Neville
- Posted on November 8, 2023
- Updated on November 6, 2025
- 10527 Views
gNSI (gRPC Network Security Interface) defines a set of gRPC-based microservices for executing security-related operations on network devices. Some of the RPCs that gNSI exposes are used to rotate security configurations on the switch.
- Written by Alok Kumar
- Posted on November 29, 2023
- Updated on July 7, 2025
- 8793 Views
This feature provides a CLI command showing the list of mac addresses that could not be learned due to hash collision in the hardware table. A hash collision occurs when two or more distinct pieces of data map to the same entry ( or slot ) in the hardware table. It can happen when the hash function used to calculate the index for a given mac address results in the already occupied index, resulting in the failure of inserting the later mac address to the hardware table.
- Written by Basil Saji
- Posted on November 9, 2020
- Updated on July 13, 2026
- 18320 Views
Private VLAN is a feature that segregates a regular VLAN broadcast domain while maintaining all ports in the same IP subnet. There are three types of VLAN within a private VLAN
- Written by Jingyao Li
- Posted on July 10, 2025
- Updated on July 10, 2025
- 2666 Views
This feature adds the support for tracking the number of syslog messages sent to the server and the number of syslog messages received on the server, along with other log forwarding action statistics, continuously within the existing syslog logging mechanism.
- Written by Bruno
- Posted on July 17, 2025
- Updated on July 17, 2025
- 2548 Views
This feature terminates GTP packets arriving on a tap port of a TapAgg switch by stripping the GTP header. The decapsulated (inner) packets then proceed through the normal TapAgg path. This functionality allows a GTPv1 tunnel to transmit tapped traffic to the TapAgg switch over an L3 network, significantly extending the available use cases for TapAgg.
- Written by Sandeep Kopuri
- Posted on October 7, 2019
- Updated on November 7, 2025
- 19327 Views
Topology Independent Fast Reroute, or TI-LFA, uses IS-IS SR to build loop-free alternate paths along the post-convergence path. These loop-free alternates provide fast convergence.
- Written by Jeff Chan
- Posted on August 19, 2020
- Updated on July 16, 2026
- 38738 Views
Access Control Lists (ACL) use packet classification to mark certain packets going through the packet processor pipeline and then take configured action against them. Rules are defined based on various fields of packets and usually TCAM is used to match packets to rules. For example, there can be a rule to match the packet source IP address against a list of IP addresses, and drop the packet if there is a match. This will be expressed in TCAM with multiple entries matching the list of IP addresses. The number of entries is reduced by masking off bits, if possible. TCAM is a limited resource, so with classifiers having a large number of rules and a big field list, TCAM runs out of resources.
- Written by Michael Wang
- Posted on July 2, 2024
- Updated on July 10, 2025
- 6051 Views
This feature introduces the ability to define matching rules to configure transceiver tuning on a switch. This is useful when a particular collection of transceivers are known to require tuning values which differ from EOS defaults.
- Written by John Weismiller
- Posted on July 23, 2025
- Updated on July 24, 2025
- 2544 Views
The "forwarding action trap" feature allows you to divert all incoming network traffic for an interface directly to the switch’s CPU for inspection and analysis. This feature is useful for advanced network testing, gaining deeper visibility into specific traffic flows, and potentially emulating existing network behaviors. Be aware that directing a high volume of network traffic to the CPU via this feature can overwhelm it.
- Written by Kallol Mandal
- Posted on April 25, 2022
- Updated on July 25, 2025
- 13898 Views
Overlay IPv6 routing over VXLAN tunnel using an anycast gateway (direct routing) has been previously supported using the “ipv6 virtual-router” configuration for both the data-plane and EVPN (or CVX) control-plane learning environments.
- Written by Matthew Carrington-Fair
- Posted on March 3, 2023
- Updated on July 7, 2026
- 9628 Views
This feature allows the export of IP FIB (Forwarding Information Base) through the OpenConfig AFT YANG models.
- Written by Nikhil Satish Pai
- Posted on July 15, 2025
- Updated on July 15, 2025
- 2554 Views
This feature allows configuring a static IS-IS neighbor to have a full adjacency on an interface, without needing an IS-IS peer at the other end.. The adjacency state will depend on the BGP session with a single hop eBGP peer presen t on the same interface: when the BGP session is established, the IS-IS adjacency will be up; in any other state, it will be down. This allows advertising an interface's traffic engineering information—like bandwidth and admin groups—within IS-IS without needing an IS-IS neighbor adjacency on the remote end.
- Written by Prasanna Parthasarathy
- Posted on December 23, 2021
- Updated on August 5, 2026
- 27773 Views
SwitchApp is an FPGA-based feature available on compatible Arista 7130 devices. It performs ultra low latency Ethernet packet switching. Its packet switching feature set, port count, and port to port latency are a function of the selected SwitchApp profile.
- Written by Vipul Shah
- Posted on August 27, 2019
- Updated on January 20, 2026
- 10870 Views
BGP routing information often contains more than one path to the same destination network. The BGP best-path selection algorithm determines which of these paths should be considered as the best path to that network
- Written by Rajeev Menon
- Posted on March 18, 2025
- Updated on July 17, 2025
- 3544 Views
The feature introduces a CLI command for transceiver reinitialization, simulating a physical removal and reinsertion of the transceiver. This is a great feature for remote troubleshooting, when physical access is not possible or convenient. To configure, issue the CLI command "transceiver reinitialize slot" in exec mode. The command takes effect immediately, toggles the reset pin and initiates a transceiver initialization sequence.
- Written by Rajeev Menon
- Posted on September 30, 2019
- Updated on July 9, 2025
- 11686 Views
This feature provides the capability to configure transceiver SERDES electrical tuning parameters. The ability to
- Written by Vipul
- Posted on July 10, 2025
- Updated on July 10, 2025
- 2743 Views
This feature makes IGMP Snooping aware of VXLAN endpoints. Without this feature, multicast data traffic is flooded to all the VXLAN endpoints in case of a VXLAN VLAN. This increases the underlay network utilization. It is desirable to forward multicast traffic to only those VXLAN endpoints that are attached to receivers. To identify interested VXLAN endpoints, this feature snoops IGMP reports that are coming from the remote VXLAN endpoints. Note: EVPN control plane is not required when using this feature.
- Written by Rohit Maurya
- Posted on August 28, 2019
- Updated on March 6, 2026
- 11541 Views
The VXLAN VTEP and VNI counters feature allows the device to count VXLAN packets received and sent by the device on a per VTEP and per VNI basis. Specifically, it enables the device to count bytes and packets that are encapsulated and decapsulated as they are passing through.
- Written by Keerthana Parthasarathy
- Posted on March 4, 2025
- Updated on March 12, 2026
- 5213 Views
Support for matching of DSCP,ECN,VLAN is available under the QOS class-map configuration on Arista switches.
