On Tue, 19 Nov 2002 12:38:15 +0100, Daniel Hartmeier wrote:
> On Tue, Nov 19, 2002 at 12:27:41PM +0100, [EMAIL PROTECTED] wrote:
>
> > come one, spend a second on it. fragmented packets with the don't fragment
> > bit set are invalid. that's so obvious.
>
> Well, there's the case where fragments can be fragmented further, the
> RFCs support that. The question is whether anyone would sanely set the
> DF bit on a fragment to prevent _further_ fragmentation.
Well, they can, but then they'd be stupid:
An internet datagram can be marked "don't fragment." Any internet
datagram so marked is not to be internet fragmented under any
circumstances.
(RFC 791)
A fragment is fragmented; ergo, it cannot be marked don't fragment.
One could argue that the "be liberal in what you accept and conservative in
what you send" rule implies that you should accept fragments with DF set, but
the potential for a host system to misinterpret such datagrams makes me
unwilling to agree.
--
Kyle R. Hofmann <[EMAIL PROTECTED]>
