Skip site navigation (1)Skip section navigation (2)
Date:      Mon, 24 Jun 2019 14:48:10 +0300
From:      "Jukka A. Ukkonen" <jau789@gmail.com>
To:        freebsd-net@freebsd.org
Subject:   Odd TCP ECN related bahavior
Message-ID:  <777f12f5-3c58-a6ef-5a92-df6be9372ec6@gmail.com>

next in thread | raw e-mail | index | archive | help

Hi all,

I am not on this mailing list. So, all responses should be sent
to my personal address.

I just noticed somewhat confusing network behavior when I was
using wireshark to understand why certain connections have been
unexpectedly slow.

My 11.3 stable (latest update 2019-06-23) seems to do this
according to wireshark...

.... ..00 = Explicit Congestion Notification: Not ECN-Capable Transport (0)

My system has this set, though...

net.inet.tcp.ecn.enable: 1

At the same time the peer system was reporting ECN capability...

.... ..10 = Explicit Congestion Notification: ECN-Capable Transport 
codepoint '10' (2)

Apparently increasing the value in...

net.inet.tcp.ecn.maxretries

doesn't help.

What should I make of this? Is the ECN implementation in 11.3 somehow
faulty or is this something more down to earth?


--jau



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?777f12f5-3c58-a6ef-5a92-df6be9372ec6>