- Written by Bharathram Pattabhiraman
- Posted on February 11, 2021
- Updated on April 20, 2026
- 36023 Views
E-Tree is an L2 EVPN service (defined in RFC8317) in which each attachment circuit (AC) is assigned the role of Root or Leaf. Root ACs can communicate with leaf ACs and other root ACs. Leaf ACs can only communicate with root ACs. Leaf AC to leaf AC traffic is blocked. In this implementation, ACs are configured at the VLAN level, and the forwarding rules are enforced using a combination of local configuration of leaf VLANs (for local hosts), and asymmetric route targets (for remote hosts).
- Written by Abhiram Kalluru
- Posted on March 4, 2025
- Updated on March 4, 2025
- 3642 Views
Nexthop Group Event Monitoring in the RPC layer on Arista switches allows for quick and filterable viewing of Nexthop Group events, i.e., addition or deletion or callbacks associated with hardware programming of Nexthop Groups configured through the EosSdkRpc agent.
- Written by Padmanabh Ratnakar
- Posted on April 20, 2021
- Updated on October 22, 2025
- 20341 Views
The postcard telemetry (GreenT - GRE Encapsulated Telemetry) feature is used to gather per flow telemetry information like path and per hop latency. For network monitoring and troubleshooting flow related issues, it is desirable to know the path, latency and congestion information for flows at different times.
- Written by Ruoyi Wang
- Posted on March 4, 2025
- Updated on March 4, 2025
- 3444 Views
When this feature is disabled, the dst_vlan field in the switch extension always equals to the src_vlan field for L2 traffic. When this feature is enabled, the dst_vlan field will be the 802.1Q VLAN ID of the outgoing frame for L2 traffic.
- Written by David Cronin
- Posted on March 3, 2022
- Updated on March 5, 2026
- 32981 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, Operators for comparing and modifying attributes, built-in functions provided in RCF
- Written by David Cronin
- Posted on March 3, 2022
- Updated on March 5, 2026
- 20301 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 Paraic Gallagher
- Posted on March 17, 2025
- Updated on March 17, 2025
- 3607 Views
Routing Control Functions (RCF) is a language that can express route filtering and attribute modification logic in a powerful and programmatic fashion.
- Written by Shamit Kapadia
- Posted on May 3, 2022
- Updated on March 10, 2026
- 13203 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.
- Written by Roger Levesque
- Posted on January 3, 2023
- Updated on January 28, 2026
- 11474 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 KernelFib agent points of application:
- Written by David Cronin
- Posted on March 4, 2022
- Updated on January 22, 2026
- 27144 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.
- Written by Shamit Kapadia
- Posted on May 3, 2022
- Updated on January 28, 2026
- 11937 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.
- Written by Paraic Gallagher
- Posted on March 17, 2025
- Updated on January 28, 2026
- 3640 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.
- Written by Kalash Nainwal
- Posted on December 14, 2020
- Updated on April 20, 2026
- 18502 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 March 3, 2025
- Updated on December 17, 2025
- 4147 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 January 13, 2026
- 23692 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 Charlotte Fedderly
- Posted on March 3, 2025
- Updated on March 3, 2025
- 3434 Views
sFlow independent configuration allows the user to configure the sFlow source and agent addresses independently of one another. This feature fixes the limitations of “sflow source-interface” where the address it uses is indeterminate when the interface has multiple addresses assigned.
- Written by Karan Jagjit Kumar
- Posted on June 29, 2023
- Updated on March 12, 2025
- 12173 Views
Smart System Upgrade (SSU) provides the ability to upgrade the EOS image with minimal traffic disruption. This is an existing feature on many fixed system products. This resource will outline the SSU feature in reference to CCS-720DP, CCS-722XPM, CCS-720XP-96ZC2, CCS-720XP-48TXH-2C, and DCS-7010TX.
- Written by Vincent (Chia Hsuan)
- Posted on September 24, 2024
- Updated on January 8, 2026
- 6941 Views
A traffic storm is a flood of packets entering a network, resulting in excessive traffic and degraded performance. Storm control prevents network disruptions by limiting traffic beyond specified thresholds on individual physical LAN interfaces. Storm control monitors inbound traffic levels over one-second intervals and compares the traffic level with a specified benchmark. The storm-control command configures and enables storm control on the configuration mode physical interface
- Written by Eamon Doyle
- Posted on March 4, 2025
- Updated on March 4, 2025
- 3596 Views
A fundamental business requirement for any network operator is to reduce costs where possible. For network operators, deploying devices to many locations can be a significant cost as sending trained specialists to each site for installations is both time-consuming and expensive.
- Written by Deepanshu Shukla
- Posted on August 21, 2020
- Updated on January 12, 2026
- 22254 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
- 10013 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 Christopher Brown
- Posted on December 16, 2020
- Updated on March 7, 2025
- 10902 Views
ARP and IPv6 Neighbor Discovery use a neighbor cache to store neighbor address resolutions. The capacity of the neighbor cache is determined by the resources and capabilities of the device platform. The neighbor cache capacity feature adds a means to specify a per-interface capacity for the neighbor cache. A neighboring device, through misconfiguration or maliciousness, can unfairly use a large number of address resolutions. This feature can help to mitigate this over-utilization.
- Written by Basil Saji
- Posted on November 9, 2020
- Updated on January 20, 2026
- 17442 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 Charlotte Fedderly
- Posted on August 25, 2020
- Updated on March 26, 2025
- 14563 Views
This feature adds support for a selected set of configured interfaces to collect egress flow samples. Egress sFlow can be configured on Ethernet and Port-Channel interfaces, and on subinterfaces on select platforms. Hardware acceleration is not currently supported for egress sFlow and all sample processing is performed in software.
- Written by Jeff Chan
- Posted on August 19, 2020
- Updated on April 14, 2026
- 36183 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 Eddie Xie
- Posted on January 31, 2024
- Updated on April 17, 2026
- 6174 Views
This TOI supplements the Ingress Traffic Policy applied on ingress port interfaces. Please refer to that document for a description of Traffic Policies and field-sets. This TOI explains the Traffic Policies as applied in the ingress direction on VLAN interfaces. For Traffic Policies on the egress direction of VLAN interfaces, see the Egress Traffic Policy TOI.
- Written by Prasanna Parthasarathy
- Posted on December 23, 2021
- Updated on April 20, 2026
- 25517 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. Detailed latency measurements are available in the user guide on the Arista Support site.
- Written by Bidong Chen
- Posted on July 5, 2024
- Updated on March 13, 2025
- 5638 Views
This feature comprises two parts:
To extend Traffic Steering to Nexthop Groups (GRE) by allowing us to specify one or more nexthop groups of type DzGRE (DANZ GRE) as the destination for a TAP aggregation steering policy. A DzGRE header will be encapsulated to the packets sending out a nexthop group of type DZGRE.
- Written by Stefan Kheraj
- Posted on October 21, 2021
- Updated on March 10, 2025
- 12496 Views
Traffic steering to nexthop groups allows specifying one or more nexthop groups as the destination, either by default for a TAP port or for a TAP aggregation steering policy. Traffic steering is a TAP aggregation process that uses class maps and policy maps to direct data streams received on TAP ports. A nexthop group is a data structure that defines a list of nexthop addresses and a tunnel type for packets routed to the specified address.
- Written by Vipul Shah
- Posted on August 27, 2019
- Updated on January 20, 2026
- 10303 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
- 3181 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 Lavanya Conjeevaram
- Posted on September 11, 2017
- Updated on July 2, 2025
- 14284 Views
Unidirectional links is a feature that configures an Ethernet interface transmit and receive paths to be independent. Specifically, the transmit path can be up or down independent of the receive path being up or down.
- Written by Gowtham Rameshkumar
- Posted on September 15, 2023
- Updated on April 2, 2026
- 8341 Views
The Unified Forwarding Table (UFT) is a group of memories that is shared between Layer2 and Layer3 lookup tables with capabilities for variable partitions. Rather than separate Layer2 and Layer3 lookup tables of fixed size, the UFT may be partitioned to support user-requested combinations of Layer2 and Layer3 lookup tables of varying sizes. The new UFT partitioning CLI has capabilities to reconfigure individual forwarding table scales (Layer2, Layer3 Unicast, Layer3 Multicast) according to the user’s input. The CLI provides an interface for granular control of the underlying UFT resources.
- Written by Anirudh Ramesh Iyer
- Posted on May 5, 2021
- Updated on April 20, 2026
- 27211 Views
This article describes how to customize TCAM ( Ternary Content Addressable Memory ) lookup for each feature which uses TCAM. The lookup is composed of fields, in the packet header / forwarding chip pipeline decisions, that are of interest to a feature. Size of the lookup determines the number of banks to be used by a feature. Traditionally, any feature uses a predefined TCAM lookup.
- Written by Peter Thompson
- Posted on March 21, 2025
- Updated on March 21, 2025
- 3380 Views
User-defined TPIDs allows an arbitrary TPID (Tag Protocol Identifier) to be used with a FlexEncap specification. A TPID is used in Ethernet frames to identify the encapsulation protocol, where standard values like 0x8100 (for IEEE 802.1q VLAN tagging) and 0x88a8 (for IEEE 802.1ad Q-in-Q) are commonly used. However, some network equipment may use non-standard or legacy values such as 0x9100. This feature allows FlexEncap subinterfaces to be configured with an arbitrary TPID to allow interfacing with networking equipment that uses values besides 0x8100 and 0x88a8.
- Written by Srinivasan Rammoorthy Mahalingam
- Posted on March 3, 2023
- Updated on March 7, 2025
- 9574 Views
This article describes the support of a VLAN filter for IP, IPV6 and MAC ACLs on the ingress ports. The users will be able to filter the packets by specifying a VLAN id in the ACL rule. VLAN id specified in the ACL rule is internal broadcast domain VLAN id.
- Written by Kallol Mandal
- Posted on March 3, 2025
- Updated on March 3, 2025
- 4356 Views
Traceroute and tracert are widely available diagnostic command-line interface commands for displaying possible routes (paths) and transit delays of packets across an Internet Protocol (IP) network. This enhancement applies to IPv4 and IPv6 overlay. The VTEP overlay ICMPs for “time-to-live expired” (aka TTL-expired) are sourced with the VTEP IP which results in the traceroute output to display the VTEP IPs on the overlay packet’s path from source to destination.
- Written by James Nakoda
- Posted on March 3, 2025
- Updated on July 2, 2025
- 3775 Views
WRAS is an EOS extension to automatically manage the layer 1 connectivity of the MetaWatch's WhiteRabbit interface.
- Written by Keerthana Parthasarathy
- Posted on March 4, 2025
- Updated on March 12, 2026
- 4592 Views
Support for matching of DSCP,ECN,VLAN is available under the QOS class-map configuration on Arista switches.
