Re: The IPv4 Internet MTU

[arno@natisbad.org (Arnaud Ebalard)]

Hi,

Iljitsch van Beijnum <iljitsch@muada.com> writes:

> On 12-okt-2007, at 23:36, Arnaud Ebalard wrote:
>
>> IPv6 packets larger than 1473 bytes sent by peers are just dropped
>> when they come back. Annoying to say the least ...
>
> A good way to work around that is by having your router advertise an
> IPv6 MTU of that size. Your hosts will then automatically reduce
> their packet sizes and advertise a reduced TCP MSS option.

I prefer MSS clamping, because it provides the same final result, but
does not make the communications inside my site undergo a reduced MTU. 

It also allows me to configure it only at a single location (edge
router) instead of doing it on a bunch of devices.

On my specific case, the MTU being asymmetric, i even get the benefit of
1500 bytes MTU for outgoing traffic.

Don't get me wrong, i *hate* mangling packets but it's IMHO a cleaner
workaround in that specific case.

a+