Re: mss to pmtu clamping partially broken?

[Phil Dibowitz <phil@ipom.com>]

On Mon, Jul 02, 2007 at 07:04:12PM +0200, Andreas Steinmetz wrote:
> Jan Engelhardt wrote:
> > Do you really need clamping? It's a hack, since TCP should do MSS negotiation
> > itself. (Of course it may happen that some routers are broken.) But usually not
> > for incoming packets.
> 
> You never know when you hit ICMP blackholes, broken routers and other
> evil things. Better safe than sorry so clamping is the way to go for me.

I encourage you to report PMTUD Blackholes to the MSS Initiative at
http://www.phildev.net/mss/

We'll notify them, and if we can't get them to fix it, blacklist them. We have
more fixed sites than blacklisted sites, so it's at least somewhat successful.

-- 
Phil Dibowitz                             phil@ipom.com
Open Source software and tech docs        Insanity Palace of Metallica
http://www.phildev.net/                   http://www.ipom.com/

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