IPv6 MTUs smaller than 1280 bytes?

[Fernando Gont]

Hi, Bill,

COmments inline...


bmanning at vacation.karoshi.com wrote:
> 	i will admit to truting what my tools tell me, and 
> 	they report an MTU of 1220.  It appears to be from a
> 	single vendors kit.

Ok, put another way: what's the mechanism these tools use to report such
MTUs?

I'm wondering if the reported MTUs correspond to link-layers that cannot
convey packets of 1280 bytes, or e.g. they are reporting "errors"
because they want your node to include a fragmentation header (but would
nevertheless *be* able to convery a packet of 1280 bytes), or maybe the
tool is inferring the MTU from the TCP MSS options. -- These two things
are different from a real link MTU smaller than 1280 bytes.

Thanks!

Kind regards,
-- 
Fernando Gont
e-mail: fernando at gont.com.ar || fgont at acm.org
PGP Fingerprint: 7809 84F5 322E 45C7 F1C9 3945 96EE A9EF D076 FFF1