rchrist.io

Another weird Arista EOS bug: Broken cEOS 4.35.0F Multicast Routing

Mon, 03 Nov 2025 00:00:00 +0000

Arista cEOS 4.35.0F Multicast Routing is broken with the default setting “software-forwarding kernel”. This blog post explores the issue and that “software-forwarding sfe” is only a partial workaround and Multicast Routing .

Audio over IP Networks for Events - An Opinionated Guide, Part 4: BGP as advanced routing protocol for when you need a little bit more spice

Sat, 01 Nov 2025 00:00:00 +0000

The state of temporary Audio over IP Networks is poor, with large, brittle stretched VLANs and redundancy provided by Spanning Tree Protocol. This article provides an introduction to BGP for Layer 3 fabrics.

The curious case of an OSPF unnumbered ECMP bug in Arista EOS

Thu, 30 Oct 2025 00:00:00 +0000

This article explores a specific bug in Arista EOS related to OSPF unnumbered, ECMP and iBGP

Audio over IP Networks for Events - An Opinionated Guide, Part 3: OSPF for self-healing networks that just work (TM)

Tue, 07 Oct 2025 00:00:00 +0000

Fixing Mellanox DMI / SMBIOS Information

Sat, 12 Jul 2025 00:00:00 +0000

Introduction

Cumulus Linux and the included Mellanox Hardware Management package (hw-mgmt) heavily rely on information from the BIOS DMI / SMBIOS to determine the system type / hardware configuration.

If this information is wrong (or rather: incompatible), you can have all kinds of funny issues, like the fans constantly running at full speed because the ASIC temperature sensor is not initialized correctly, or the thermal control loop using wrong thresholds or PWM addresses…

How to mod Mellanox FRU EEPROMs under Cumulus Linux

Sat, 12 Jul 2025 00:00:00 +0000

Some OEM FRUs (fans or PSUs) for Mellanox switches may cause issues under Cumulus Linux due to OEM PNs in the EEPROMs. This guide explains how to modify the EEPROMs to resolve these issues.

Tips & Tricks for Cumulus Linux

Sat, 12 Jul 2025 00:00:00 +0000

A collection of tips and tricks for Cumulus Linux

Audio over IP Networks for Events - An Opinionated Guide, Part 2: Layer 3 Network Design Principles

Mon, 02 Jun 2025 00:00:00 +0000

Audio over IP Networks for Events - An Opinionated Guide, Part 1: Foundations and why L2 is considered harmful

Thu, 29 May 2025 00:00:00 +0000

The state of temporary Audio over IP Networks is poor, with large, brittle stretched VLANs and redundancy provided by Spanning Tree Protocol. This article covers the basic design goals for such networks and establishes why L2 should be considered harmful.

Unlocking "more" recirculation bandwidth on Arista 7050X switches

Sun, 05 Jan 2025 00:00:00 +0000

Arista 7050X series switches have some undocumented commands, which allow you to unlock “more” bandwidth for recirculation without disabling physical ports. Read about how and why.

About Me & Services

Mon, 01 Jan 0001 00:00:00 +0000

About Robin Christ

Contact & PGP Keys

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Contact Me & PGP Keys

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Sponsoring

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