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