- Written by Jack Jiang
- Posted on 10月 10, 2025
- Updated on 10月 10, 2025
- 1827 Views
Precision Time Protocol (PTP) is a protocol aimed at distributing time between devices with sub-microsecond accuracy. PTP support is based on the IEEE-1588 specification for version 2 of the protocol. cEOS-lab is a containerised image which provides a portable way to run EOS in a virtualised environment. With this support, multiple virtual labs can be spun up to be used for testing and learning of the PTP feature.
- Written by Rahul Sharma
- Posted on 10月 10, 2025
- Updated on 10月 10, 2025
- 1596 Views
This feature allows a customer to configure a whitelist of acceptable grandmaster clocks per switch. When such a list is configured, announce messages from only the acceptable clocks are accepted and announce messages from all other clocks are rejected. If there is no such list configured, the default behaviour kicks in i.e. all potential grandmaster clocks are considered.
- Written by Jeff Chan
- Posted on 5月 17, 2018
- Updated on 10月 22, 2025
- 11180 Views
Previously, EOS only supported the two-step variation of the transparent clock as described in the IEEE 1588 Specification. In this release, we now support one-step end-to-end transparent clock on certain platforms.The main advantage of a one-step end-to-end transparent clock is that all PTP packets are completely handled in the forwarding plane, whereas in the two-step variation, PTP messages need to be handled in the control plane. This removes scaling limitations such as packet drops due to high packet intervals and reduces CPU utilization.
- Written by David Cronin
- Posted on 3月 3, 2022
- Updated on 3月 5, 2026
- 32918 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 3月 3, 2022
- Updated on 3月 5, 2026
- 20259 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 Shamit Kapadia
- Posted on 5月 3, 2022
- Updated on 3月 10, 2026
- 13174 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 David Cronin
- Posted on 3月 4, 2022
- Updated on 1月 22, 2026
- 27105 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 Michael (Mike) Fink
- Posted on 11月 11, 2019
- Updated on 11月 7, 2025
- 13320 Views
Packets sampled for sFlow are packaged in a flow sample structure containing, amongst other things, input and output
- Written by Yeshwanth G
- Posted on 10月 10, 2025
- Updated on 10月 24, 2025
- 1336 Views
The command provides a summary of the number of used hardware entries versus the total available capacity for various Layer 3 features, such as next-hops and ECMP groups. Network operators run this to quickly assess the health of the forwarding plane and determine if the device is approaching its resource limits. This command also details the usage of different levels of the ALPM tables and TCAMs.
- Written by Hari Prasad S R
- Posted on 8月 19, 2025
- Updated on 1月 12, 2026
- 2548 Views
"Micro segment" (SRv6 uSID or uSID for short) is an extension of SRv6 architecture, specifically designed to represent SRv6 SIDs in an extremely compact way. It addresses the overhead of using full 128-bit IPv6 SIDs for routing. Instead of using a 128-bit address for single SID, multiple uSIDs are packed into a single 128-bit address. Each 128-bit address comprises a block value representing the domain followed by multiple uSIDs, each of the same bit length. If there are bits left they are filled with trailing zeros. This allows for a complete SRv6 path to be represented by a 128-bit IPv6 address. Like a regular SID, each uSID is associated with a specific behavior on the SRv6 capable node. SRv6 uN refers to the End behavior with uSIDs.
- Written by Thejesh Panchappa
- Posted on 5月 1, 2015
- Updated on 1月 19, 2026
- 14728 Views
This is an infrastructure that provides management of SSL certificates, keys and profiles. SSL/TLS is an application-layer protocol that provides secure transport between client and server through a combination of authentication, encryption and data integrity. SSL/TLS uses certificates and private-public key pairs to provide this security. A user can manage certificates, keys and also multiple SSL profiles. An SSL profile is a configuration which includes certificate, key and trusted CA certificates used in SSL/TLS communication. An SSL profile configuration can be attached to another EOS configuration which supports SSL/TLS communication. Individual EOS features that use this infrastructure will document the details of using an SSL profile in their configuration.
- Written by Ashit Tandon
- Posted on 11月 6, 2025
- Updated on 11月 6, 2025
- 1395 Views
This feature allows a switch to statically modify the source or destination IP (and optionally the L4 port) for a transit packet. Static NAT support on 7050X3, 720XP and 720D platforms was first introduced in 4.21.6F. Starting at EOS 4.35.0F, NAT functionality is supported on certain 7050X4 and 7358X4 platforms.
- Written by Satish Mahadevan
- Posted on 4月 21, 2015
- Updated on 10月 13, 2025
- 9409 Views
Subinterfaces are logical L3 interfaces that enable the division of a single Ethernet or Port-channel interface into multiple logical L3 interfaces based on the incoming 802.1q tag. They are commonly used in the L2/L3 boundary. They can also be used in the context of VRF-lite, by configuring each subinterface in a different VRF.
- Written by Haomin
- Posted on 10月 10, 2025
- Updated on 10月 10, 2025
- 1515 Views
Dynamic NAT Priority feature, which extends the Dynamic NAT feature, allows you to configure the order in which dynamic NAT rules are evaluated by the switch.
- Written by Brian Neville
- Posted on 11月 8, 2023
- Updated on 11月 6, 2025
- 9982 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 Basil Saji
- Posted on 11月 9, 2020
- Updated on 1月 20, 2026
- 17396 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 Venkata Vyshnav Lagisetty
- Posted on 3月 1, 2024
- Updated on 11月 3, 2025
- 1392 Views
The feature adds support for redirecting traffic matching on traffic policy rules applied to an egress interface to a specified next-hop or next-hop group. This feature requires the packet to be recirculated a second time through the packet forwarding pipeline to get its configured single or multiple next-hops to be resolved. This is achieved by configuring traffic-policy with redirect interface action applied on egress interface in conjunction with ingress redirect next-hop action applied on the recirculation interface.
- Written by Sandeep Kopuri
- Posted on 10月 7, 2019
- Updated on 11月 7, 2025
- 18285 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 John Weismiller
- Posted on 8月 12, 2025
- Updated on 10月 21, 2025
- 2772 Views
The Traffic Generator is an EOS feature that allows network traffic generation on Arista switches. It provides a simple and effective way to create high-speed traffic for testing and validation purposes. It can send a continuous stream of custom-defined packets at full speed to one or more destination interfaces
- Written by Jeff Chan
- Posted on 8月 19, 2020
- Updated on 4月 14, 2026
- 36084 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 Muhammad Yousuf
- Posted on 9月 9, 2021
- Updated on 4月 2, 2026
- 14309 Views
This TOI supplements the Ingress Traffic Policy applied on ingress 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 egress direction on interfaces.
- Written by Vallela Kaushik Shashank Reddy
- Posted on 6月 20, 2022
- Updated on 1月 16, 2026
- 6781 Views
This feature enables the support of applying a policy-map in egress direction on an SVI interface. A policy-map is a QoS feature in which we have multiple class-maps each with a match criteria and an action. These class-maps match on the given criteria and the configured action is applied on the traffic which matches. We can apply these policy-maps on interfaces in both input and output directions which match on ingress and egress traffic respectively. This feature adds the support of applying such output policy-map on an SVI( Switch Virtual Interface ).
- Written by Matthew Carrington-Fair
- Posted on 3月 3, 2023
- Updated on 11月 4, 2025
- 9155 Views
This feature allows the export of IP FIB (Forwarding Information Base) through the OpenConfig AFT YANG models.
- Written by Josh Pfosi
- Posted on 10月 16, 2025
- Updated on 4月 6, 2026
- 5316 Views
SWitch Aggregation Group (SWAG) is a feature in EOS that supports combining multiple physical switches into a single, powerful virtual switch, simplifying network management and increasing scalability. This document describes how to configure and troubleshoot a SWAG.
- Written by Lucas Frere
- Posted on 11月 17, 2023
- Updated on 11月 4, 2025
- 8849 Views
Slice reservation can be used to solve TCAM resources limitations due to suboptimal group order in the TCAM because of the FCFS (First come first serve) nature of the TCAM. The user will be able to reserve a certain amount of entries in the TCAM for a specific feature. The configuration happens through a new keyword in feature mode when configuring a TCAM profile.
- Written by Olufemi Komolafe
- Posted on 10月 22, 2025
- Updated on 11月 3, 2025
- 1825 Views
At its most basic level, as shown in Figure 1, the packet forwarding pipeline for a switch with an application-specific integrated circuit (ASIC) typically consists of ingress pipelines and egress pipelines, a memory management unit for storing and transmitting packets and metadata between the pipelines, and a path to punt packets and receive instructions from the central processing unit (CPU).
- Written by Swaroop George
- Posted on 4月 15, 2021
- Updated on 10月 21, 2025
- 12483 Views
This feature allows selecting Differentiated Services Code Point (DSCP) and Traffic Class (TC) values for packets at VTEPs along VXLAN encapsulation and decapsulation directions respectively. DSCP is a field in IP Header and TC is a tag associated with a packet within the switch, both influence the Quality of Service the packet receives. This feature can be enabled via configuration as explained later in this document.
