AMS-IX lost 8 Tbps of traffic due to a subtle problem with the LACP protocol, networking conferences

Network failures can have a huge impact and force large traffic movements. A [problem with the LACP protocol]( on [AMS-IX](, one of the largest Internet eXchange Point caused a drop of more than 8 Tbps of traffic in Amsterdam. This was a serious event for the European Internet as show in the screenshot below.


AMS-IX provides some information about this outage on their [blog]( In addition, Emile Aben looked at RIPE Atlas data and other public information to try to understand whether these 8 Tbps of traffic moved. His [analysis appears on the RIPE blog]( and was [presented at RIPE87]( At the same meeting, Stavros Konstantaras, one of the engineers responsible for AMS-IX [presented a detailed post-mortem analysis]( of the event showing that it was caused by a problem with the treatment of LACP messages that led to a cascade of other problems.

This is a good opportunity to encourage students to follow the various conferences where network operators regularly meet. RIPE organizes such conferences in Europe and 87th one took place in Roma in November 2023. All presentations, slides, recordings and even transcripts are publicly available from []( Smaller events are also interesting such as [the meeting of the UK IPv6 council]( for those willing to track the deployment of IPv6. 


This blog aims at encouraging students who read the open Computer Networking: Principles, Protocols and Practice ebook to explore new networking topics. You can follow this blog by subscribing to its RSS feed or by following @cnp3_ebook on mastodon.

Written on December 4, 2023