nanog mailing list archives
Re: MTU problems with GRE tunnels (fwd)
From: Dave Thaler <thalerd () eecs umich edu>
Date: Tue, 7 Jul 1998 17:08:36 -0400 (EDT)
Dennis Ferguson
I can tell you for sure that the Cisco routers do send the packets (GRE or IP protocol 4) with a length which includes the IP header, just like the RFC. If you look I think you'll find that it is your kernel which is subtracting out the IP header length before it hands the packet to you on the raw socket.
BSD Unix converts the length to host order and subtracts the IP header length. Linux leaves the length in net order (don't know about subtracting). Windows leaves the length in net order and does not subtract the IP header length. -Dave
Current thread:
- MTU problems with GRE tunnels (fwd) Jens Schweikhardt (Jul 06)
- IpinIP tunnels - was Re: MTU problems with GRE tunnels (fwd) Paul Mansfield (Jul 06)
- Re: MTU problems with GRE tunnels (fwd) Alex P. Rudnev (Jul 06)
- Re: MTU problems with GRE tunnels (fwd) Dennis Ferguson (Jul 07)
- Re: MTU problems with GRE tunnels (fwd) Dave Thaler (Jul 09)
- Re: MTU problems with GRE tunnels (fwd) Jens Schweikhardt (Jul 09)
- Re: MTU problems with GRE tunnels (fwd) Dave Thaler (Jul 09)
- <Possible follow-ups>
- Re: MTU problems with GRE tunnels (fwd) BrandonButterworth (Jul 06)