> > > RFC 4821 PMTUD is that "negotiation" that is "lacking". It is there.
> > > It is deployed. It actually works. No more relying on someone sending
> > > the ICMP packets through in order for PMTUD to work!
> >
> > For some value of "works". There are way too many places filtering
> > ICMP for PMTUD to work consistently. PMTUD is *not* the solution,
> > unfortunately.
>
> I guess you missed the part about 4821 PMTUD does not rely on ICMP.
>
> Modern PMTUD does not rely on ICMP and works even where it is filtered.
As long as the implementations are few and far between:
https://www.psc.edu/~mathis/MTU/
http://www.ietf.org/mail-archive/web/rrg/current/msg05816.html
the traditional ICMP-based PMTUD is what most of use face today.
Steinar Haug, Nethelp consulting, sth...@nethelp.no
