nanog mailing list archives

Re: IPv6 day and tunnels


From: Mark Andrews <marka () isc org>
Date: Wed, 06 Jun 2012 00:55:06 +1000


In message <E1829B60731D1740BB7A0626B4FAF0A65D374A86CB () 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.

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


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