option 212 for 6RD

Trevor Warwick (twarwick) twarwick at cisco.com
Fri Jan 25 11:05:14 CET 2013

OK, let me look at this offline and get back to you. The code is definitely present in that version, so it's either a bug or a config. issue.


-----Original Message-----
From: Mikael Abrahamsson [mailto:swmike at swm.pp.se] 
Sent: 25 January 2013 08:52
To: Trevor Warwick (twarwick)
Cc: Ivan Pepelnjak; ipv6-ops at lists.cluenet.de
Subject: RE: option 212 for 6RD

On Thu, 24 Jan 2013, Trevor Warwick (twarwick) wrote:

> In IOS 15.2(4)M and later, the "ip tcp adjust-mss" command will also 
> cause the same configured value to be used for adjusting IPv6 TCP 
> connections.

I tried this on my 6rd tunnel interface and it didn't work (no change seen on IPv6 MSS in either direction).

After reading your email I also tried to configure it on the uplink interfaces (they do IPv4/IPv6 native forwarding, no MPLS), and it didn't seem to make any difference (command used was "ip tcp adjust-mss 1200").

Cisco IOS Software, 7301 Software (C7301-ADVIPSERVICESK9-M), Version 15.2(4)M2, RELEASE SOFTWARE (fc2)


Mikael Abrahamsson    email: swmike at swm.pp.se

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