Internet Exchanges supporting jumbo frames?

Thu Mar 10 17:16:46 UTC 2016

On Thu, 10 Mar 2016, Tassos Chatzithomaoglou wrote:

> Mikael Abrahamsson wrote on 10/3/16 18:21:
>>
>> However, I stand by my earlier statement that we need to include MTU/MRU in ND messages, so that this can be negotiated on a LAN where not all devices support large MTU.
>>
>
> Isn't this already supported?
> https://tools.ietf.org/html/rfc4861#section-4.6.4

That is in RAs, and pertains to a prefix. Also, if a device can't use the 
advertised MTU, they will keep lower MTU which might be causing MTU 
mismatch.

For instance, if I announce 9000 as MTU and a device is bridged via wifi, 
wifi chips generally only supports around 2300 in MTU, so you'll have MTU 
mismatch with MTU blackholing within the same L2 network. This is bad.

-- 
Mikael Abrahamsson    email: swmike at swm.pp.se