www.eftps.gov contact

[Brian E Carpenter]

On 21/12/2012 14:58, Bill Owens wrote:
> On Fri, Dec 21, 2012 at 08:48:03AM +0000, Brian E Carpenter wrote:
>> On 21/12/2012 08:24, Ignatios Souvatzis wrote:
>>> On Wed, Dec 19, 2012 at 11:22:58AM +0200, Sander Steffann wrote:
>>>> Hi,
>>>>
>>>>> Really? Can't you set the MTU to 1280? That should fix it.
>>>> Although everybody on the internet could lower their MTU to 1280,
>>>> it would be easier if they properly send ICMP errors :-)
>>> If everybody would lower their MTU to 1280, 
>> "everybody" in this context means hosts, not tunnel operators, who
>> should go as high as possible, of course. 1280 at the host allows
>> for a couple of encapsulations inside a physical 1500 limit.
> 
> If people *insist* on deploying broken and apparently unrepairable middleboxes, the least they can do is reduce the TCP MSS on their hosts to 1220 bytes, thus limiting the IPv6 MTU at 1280 bytes. That impacts the performance of their webservers, but doesn't affect the rest of us who actually know how to configure our networks. 

Yes, I've seen MSS negotiation fail over a tunnel.

But people who have the other brokenness are not necessarily going
to fix this either.

    Brian