[153323] in North American Network Operators' Group
Re: IPv6 day and tunnels
daemon@ATHENA.MIT.EDU (Owen DeLong)
Mon Jun 4 21:00:49 2012
From: Owen DeLong <owen@delong.com>
In-Reply-To: <4FCD53BD.9050204@necom830.hpcl.titech.ac.jp>
Date: Mon, 4 Jun 2012 17:57:06 -0700
To: Masataka Ohta <mohta@necom830.hpcl.titech.ac.jp>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Jun 4, 2012, at 5:33 PM, Masataka Ohta wrote:
> Joe Maimon wrote:
>=20
>> pMTU has been broken in IPv4 since the early days.
>=20
>> It is still broken. It is also broken in IPv6. It will likely
>> still be broken for the forseeable future. This is
>=20
>> Relying on ICMP exception messages was always wrong for normal =
network operation.
>=20
> Agreed.
>=20
> The proper solution is to have a field in IPv7 header to
> measure PMTU. It can be a 8 bit field, if fragment granularity
> is 256B.
>=20
> Masataka Ohta
If you're going to redesign the header, I'd be much more interested in =
having 32 bits for the destination ASN so that IDR can ignore IP =
prefixes altogether.
Owen
