-On [20010808 16:30], Mike Tancsa ([EMAIL PROTECTED]) wrote:
>
>Just wondering, is there a reason why the MTU of the gif interface defaults
>to 1280 ? Why not 1500 ?
Per RFC2460:
"IPv6 requires that every link in the internet have an MTU of 1280
octets or greater. On any link that cannot convey a 1280-octet packet
in one piece, link-specific fragmentation and reassembly must be
provided at a layer below IPv6.
Links that have a configurable MTU (for example, PPP links [RFC1661])
must be configured to have an MTU of at least 1280 octets; it is
recommended that they be configured with an MTU of 1500 octets or
greater, to accommodate possible encapsulations (i.e., tunneling)
without incurring IPv6-layer fragmentation."
Actually I am wondering about it now myself. X.25 is one of the few
link layer protocols left which has a MTU < 1500 (aside from 802.3's
1492).
Maybe some IPv6 guru is able to shed some light?
--
Jeroen Ruigrok van der Werven/Asmodai asmodai@[wxs.nl|freebsd.org|xmach.org]
Documentation nutter/C-rated Coder, finger [EMAIL PROTECTED]
http://www.freebsd.org/doc/en_US.ISO8859-1/books/developers-handbook/
Light-in-Darkness, lift me up from here...
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