IPv6 day and tunnels

Tue Jun 5 15:00:59 UTC 2012

> -----Original Message-----
> From: Mark Andrews [mailto:marka at isc.org]
> Sent: Tuesday, June 05, 2012 7:55 AM
> To: Templin, Fred L
> Cc: Owen DeLong; Jimmy Hess; nanog at nanog.org
> Subject: Re: IPv6 day and tunnels
> 
> 
> In message <E1829B60731D1740BB7A0626B4FAF0A65D374A86CB at XCH-NW-
> 01V.nw.nos.boeing
> .com>, "Templin, Fred L" writes:
> > A quick comment on probes. Making the tunnel ingress probe
> > is tempting but fraught with difficulties; believe me, I
> > have tried. So, having the tunnel ingress fragment when
> > necessary in conjunction with the original source probing
> > is the way forward, and we should advocate both approaches.
> >
> > RFC4821 specifies how the original source can probe with
> > or without tunnels in the path. It does not have any RTT
> > delays, because it starts small and then tries for larger
> > sizes in parallel with getting the valuable data through
> > without loss.
> 
> It's useful for TCP but it is not a general solution.  PTB should
> not be being blocked and for some applications one should just force
> minimum mtu use.

Any packetization layer that is capable of getting duplicate
ACKs from the peer can do it. Plus, support for just TCP is
all that is needed for the vast majority of end systems at
the current time.

Thanks - Fred
fred.l.templin at boeing.com 

> > Thanks - Fred
> > fred.l.templin at boeing.com
> --
> Mark Andrews, ISC
> 1 Seymour St., Dundas Valley, NSW 2117, Australia
> PHONE: +61 2 9871 4742                 INTERNET: marka at isc.org