Re: Bug#104450: ITP: tcptraceroute -- A traceroute implementation using TCP packets

[David Coe <davidc@debian.org>]

I'm no expert, but from a quick scan of RFC 2481, section "6.1.1.  TCP
Initialization," it sounds to me like the ECN flags in *SYN* packets
only declare the host's ability to participate in ECN.  Since
tcptraceroute only sends SYN packets (I believe), it doesn't get
blocked because of ECN.

This is a good thing, I think.

christophe barbé <christophe.barbe@lineo.fr> writes:

> This is a little offtopic.
> 
> When I saw your ITP mail I said myself that tcptraceroute could be usefull
> to find non ecn compliant server. In fact when you turn on ecn on a 2.4
> kernel you expose yourself to unreachable sites due to broken server on the
> road.
> You can't find the broken server with traceroute because it doesn't send
> tcp packets.
> So I've tried tcptraceroute and surprisingly it is not concerned by ecn.
[...]
> 
> So my question is why.