ECN

Tue Nov 12 00:55:14 UTC 2019

> On Nov 11, 2019, at 05:01 , Baldur Norddahl <baldur.norddahl at gmail.com> wrote:
> 
> Hello
> 
> I have a customer that believes my network has a ECN problem. We do not, we just move packets. But how do I prove it?

Are you saying that none of your routers support ECN or that you think ECN only applies to endpoints?

> Is there a tool that checks for ECN trouble? Ideally something I could run on the NLNOG Ring network.
> 
> I believe it likely that it is the destination that has the problem.

I’d say start with asking the reporter to provide a PCAP of the problem and review the packet trace to provide clues of tap points
in your network to investigate where ECN is (or should be) occurring and the opposite is occurring.

Owen