[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Evolution of the IP model - ICMP and MTUs
Thanks for the RFC4821 and M Petit-Huguenin's I-D references. I knew and
their predecessors but had not read these two.
The value of PMTUD mechanisms that work even when ICMP error messages
are missing is clear.
Yet, since convergence to the right PMTU can be much faster if ICMP
error messages are forwarded and processed, it seems useful to have this
fact well understood, and advertised.
NAT and FW providers have IMO to keep (or restore) their motivation to
forward ICMP error messages on established connections.
Dan Wing - Le 8/18/08 8:58 AM :
I don't recall if RFC4821 was included in your earlier list. RFC4821
describes how to do Path MTU Discovery without ICMP.
As you know, doing PMTUD over UDP requires each application to do it
themselves. Marc Petit-Huguenin describes how to do RFC4821-style (that is,
ICMP-less) PMTUD for UDP in draft-petithuguenin-behave-stun-pmtud-01, provided
the application can demultiplex STUN messages from its normal application
payloads (the STUN magic-cookie and the STUN fingerprint can be used to demux,
which makes demuxing easier).