Re: MTU to CDN's

[Mikael Abrahamsson <swmike () swm pp se>]

On Mon, 8 Jan 2018, joel jaeggli wrote:

> PMTUD has a lot of trouble working reliability when the destination of
> the PTB  is a stateless load-balancer.
>
> If your tunnel or host clamps the mss  to the appropriate value it can
> support. it is highly likely that connection attempts to the same
> destination will work fine.

This is understandable, but if this is also an operational practice we as 
the operational community want to condone (people using solutions where 
PMTUD doesn't work), then we also need to make sure that all applications 
do PLMTUD (RFC4821, Packet Level MTU Discovery). This is currently NOT the 
case, and from what I can tell, there isn't even an IETF document saying 
this is the best current practice.

So, is this something we want to say? We should talk about that.

--
Mikael Abrahamsson    email: swmike () swm pp se