• Tag : EOS


Curl’ing with EOS and third party devices

Perhaps you’re aware that EOS is based on Linux, which comes with many powerful & useful built-in utilities. I recently wrote an EOS Central article on sed. Even if you are not a pure networking person (perhaps you’re a server person), many of the familiar Linux tools you have used in your past exist on EOS natively today. One of my customers recently shared an experience with me that made me smile because they had now started to embrace the Linux underpinnings & power of EOS after running into a configuration challenge with a 3rd party (television) broadcast IP/SDI gateway...
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A simple GNU sed example on EOS

Hopefully by now you are aware that Arista EOS (Extensible Operating System), which is the operating system that runs on Arista switches, is based on Linux. From the CLI you can drop to the Bash shell by just typing bash. Given that EOS is based on Linux you already have access to many of the helpful utilities seen in many Linux distributions. Let’s pretend that you have a configuration file that was copied over from another very similar configuration and that the only thing that needs to change is every occurrence of IP addresses that look like 10.0.x.y. This is...
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A Simple Quality of Service Design Example

While there is plenty of documentation available discussing the individual mechanics of Quality of Service, such as Class of Service (CoS) or Differentiated Services Code Point (DSCP) markings and what they mean, there is not as much documentation available bridging the gap from those basic building blocks to a working network QoS deployment. There are some understandable reasons for that lack of documentation, because the design and implementation of a QoS policy on a network is so closely coupled to the specific network’s business objectives and policies that it’s hard to develop much of a QoS policy and have it...
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Arista EOS – IPv6 RFC Compliance

Arista EOS Software is in compliance with the following IPv6 RFCs: RFC 8200 – Internet Protocol, Version 6 (IPv6) Specification RFC 4861 – Neighbor Discovery for IP version 6 (IPv6) RFC 4862 – IPv6 Stateless Address Autoconfiguration RFC 4443 – Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification RFC 8504* – IPv6 Node Requirements RFC 1981 – Path MTU Discovery for IP version 6 RFC 2464 – Transmission of IPv6 Packets over Ethernet Networks RFC 2474 – Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers (IPv4) RFC 4213 –...
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A Simple OSPF Configuration

At this point in your networking career you’ve mastered the L2 domain. I can recall several years ago when I was an embedded software engineer (programming NPUs – Network Processing Units for a networking startup) meeting a colleague that was a master of the L2 domain. This individual knew everything you wanted to know about L2, including non-Ethernet protocols. Then came the day when I was drawing a network diagram with L3 interfaces and diagramming the packet formats at the points of ingress and egress through each L3 hop. My L2 Grandmaster looked at me with a blank stare. I...
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clear platform trident counters

Hi Forum we currently troubleshoot input discards. we found the rich command show platform trident counters for our platform.(DCS-7050SX3-48YC8-F) I’ve tried to reset counter to have a blank situation. I’ve used: clear platform trident counters this cause reset of all interfaces in LAG on this switch. January 23rd 2020, 10:22:02.000 MODULE_RESET 6 Informational Switch Linecard0/0 restarting. Cause: Strata-FixedSystem crashed January 23rd 2020, 10:22:02.000 UNEXPECTED_RESTART 3 Error Unexpected restart of Strata agent Strata-FixedSystem occurred after my mistake i’ve checked the documentation about this clear command, but i didn’t found any reference. does someone has knowledge what the clear platform trident counters...
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Hybrid cloud connectivity with Arista’s Extensible Operating System (EOS) and Amazon Web Services (AWS)

Motivation The term Hybrid Cloud is not clearly defined but the most common definition is a scenario where a customer wants to combine resources in their own data centre (the private cloud) with resources in the public cloud. To allow these services to communicate, a connection between the two cloud environments needs to be established. Most cloud providers offer two options: An Internet Protocol Security (IPsec)-based Virtual Private Network (VPN) connection using the Internet as a transport media and a private link using dedicated lines or equivalent technology. In this article, we cover the VPN based approach using EOS-based services...
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How do I know which version of code I should run?

Newish to Arista. I have a pair of DCS-7280SR-48C6-M-F that I am getting ready to deploy. They’re currently running, but that was loaded months ago in the lab. How do I know which version of code I should be running? Does Arista have a software selector tool or matrix to help guide customers to the most appropriate release? Thanks. Mike

DCS-7124 EOS Versions?

Hi all; Very new to Arista; I have a dcs-7124sx and was wondering what the latest and greatest version of EOS I can safely upgrade this to? does anyone know if there is a limit? Docs say End of Life EOS 4.1.3; but i just performed full recover on this switch and its booting 4.6.2? Thus my question regarding the EOS version I can install. Thank You for any help…

Network CI/CD Part 1 – Building network topologies with Docker and cEOS-lab

Introduction As the networking industry continues riding the DevOps wave and network engineers become more comfortable using automation tools like Ansible and Salt, network still remains the most brittle piece of IT infrastructure. Partially this can be justified by the fact that network underpins all other areas of IT infrastructure stack – compute, storage and virtualisation. However we, as network engineers, have done very little to improve our confidence in networks and until now some of the biggest outages were caused by trivial network configuration mistakes. When software industry was facing similar challenges, the response was to create Continuous Integration (CI) pipelines –...
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vEOS-Lab on Hyper-V

Introduction There are multiple ways to setup a vEOS-Lab environment if you have a linux system or on hypervisors such as VMware ESXi, vCenter, VM Workstation, VM Fusion, Virtualbox, etc using the vmdk provided in the Software downloads page. But if you have a Windows machine or a Windows server, the vmdk will not be useful. So here are the steps on how you can convert the vmdk to a  vhdx and create a vEOS VM on Hyper-V. Pre-requisites 1. Hyper-V Manager and Hyper-V 2. vEOS-Lab vmdk 3. Aboot ISO  Instructions Steps 1. Download the vEOS vmdk for the EOS version...
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Enabling Passive/Transparent Devices for PTP Multicast Routing

Why is PTP Multicast Routing Needed? PTP is a highly precise time protocol, the best practice for PTP is to introduce devices as PTP-Transparent (vs Passive) if the device is L3 and does not act as Boundary Clock. Any introduction of PTP-Passive devices in the path reduces the accuracy of the protocol. Both Transparent and Passive devices require additional configuration in order to forward the PTP stream. If a device must also manage a control-plane flow (and hence has a dependency on the control traffic), this can also reduce the accuracy of PTP.  Due to this, and as the capability for a...
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Understanding EOS Software Download Options

This post is to help explain the different Software Download options for a particular EOS release. For recommendations on which train or version of EOS you should use, please take a look at our Software Lifecycle, and Recommended Release pages. This advice only concerns images located in the Active and Support Only Releases folder. Images from the Other Releases and EFT folders are not for general use. Those releases are available only for specific deployments, and should only be used when specifically recommended by Arista. In this case, I’m taking a look at EOS-4.17.1F and you can see from the...
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Deploying Virtual SAN Over L2/L3 Networks with Arista Networking Devices

This is a great posting from on how to deploy Virtual SANs over an Arista underlay networks with the actual switch configurations. Here is the video on how to automate the deployment of a VSAN infrastructure from the same blog – VMware Virtual SAN Stretched Cluster Automated Deployments with PowerCLI Thought our user community would benefit from these blog postings. Happy reading!    

Introduction to Managing EOS Devices – Memory Utilisation

A common question that users new to EOS have is concerning the high levels of memory utilisation seen on Arista switches (~70% utilised). Typically this is first flagged by the NMS and triggers a low memory warning or alarm. Unlike a traditional switching OS, EOS uses Linux page caching. Most free memory is used as a live cache and very low ‘free memory’  numbers are entirely normal, providing that enough memory is available from the buffers and cached memory for applications demanding more RAM. In this case, the OS is capable of freeing up memory from cache as processes demand it. Memory...
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Upgrade Questions for EOS

We are about to upgrade our Arista switches to address the newest vulnerabilities that came out recently, and I have a few questions I’m hoping you can help with. Some of our switches are on older hardware. Is there a table somewhere that lists the highest code level a particular platform can run? Will all newer code releases run on all older hardware? Some of our switches are running very old code. Does SSU work on very old code (say, 4.5)? Assuming not, what is the upgrade path to get these switches up to 4.14…? Do I have to upgrade...
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Script to update EOS in sw’s in a bulk

Hi We want to upgrade EOS in sw’s. We want to automate this process. We can use solarwinds to execute a script or a phython script to do it. If someone can provide with template for it so we can test it in a lab sw and use it in production.   Thanks Raj  


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