Caching learned MSS/MTU values

[Templin, Fred L]

Hi Hannes,

> -----Original Message-----
> From: ipv6-ops-bounces+fred.l.templin=boeing.com at lists.cluenet.de [mailto:ipv6-ops-
> bounces+fred.l.templin=boeing.com at lists.cluenet.de] On Behalf Of Hannes Frederic Sowa
> Sent: Friday, October 25, 2013 1:49 PM
> To: Templin, Fred L
> Cc: Jason Fesler; IPv6 operators forum
> Subject: Re: Caching learned MSS/MTU values
> 
> On Fri, Oct 18, 2013 at 10:23:00PM +0000, Templin, Fred L wrote:
> > Hi Hannes,
> >
> > > Oh, that is interesting. I'll have a look at the weekend.
> >
> > OK. I had to roll another version to make some minor
> > changes - see:
> >
> > http://linkupnetworks.com/seal/sealv2-0.2.tgz
> > http://www.ietf.org/id/draft-templin-intarea-seal-64.txt
> >
> > I will let it rest for now, so this would be the version to
> > start looking at. Let me know if there are any questions or
> > comments.
> 
> Do you plan to convert them to git for easier patch management? I would
> highly recommend it

Sure - do you have instructions on how to do this?

> (it would also be necessary if you strive upstream inclusion).

The code is still a long ways off from proposing for upstream
inclusion, but I will definitely keep this in mind.

> Could you tell me an exact date or commit id where you cloned these
> files from?

I pulled the tarball from:

https://www.kernel.org/pub/linux/kernel/v3.0/linux-3.10.12.tar.xz

and made the edits directly in those files.

> Regarding IPv6 PMTU issues: it seems we had some rather broken behaviour
> in linux for some time. In some cases races could lead to complete
> blackholes to some IPv6 destinations for minutes. In the end it seemed
> pretty good reproduceable and I wonder why not many more people did
> report bugs.  I hope the relevant patches will land in one of the next
> stable kernels. It is not always a bad configured bad firewall. ;)

Yes, there are at least two things that would help - RFC4821 for
hosts and SEAL for tunnels.

Thanks - Fred
fred.l.templin at boeing.com
 
> Greetings,
> 
>   Hannes