[nsp] IP Tunneling

[Marius Strom]

Due to some delays in getting a PtP T1 circuit up and going, a client
has come across the need to tunnel IP from a Linux 2.4 box and a Cisco
3640 (C3640-I-M, IOS 12.1(8)).  Tunnel config on the Cisco is pretty
straightforward, with an IP address, destination, and source, set for
GRE/IP.  Ditto on the Linux box: GRE, IP, destination and source.  

The tunnel is up and passing traffic.  However, some people on the
network behind the Linux box (the "default destination" is the Cisco
side of the network, both source and destination) have complained about
reachability to various websites, and we're seeing occasional TCP
timeouts during simple things like https and smtp transactions.  

Not to start a holy war, but replacing the Linux box with something,
erm, better, isn't an option at this point.

Anyone else had any luck getting Linux/Cisco GRE tunnels to play nice
together and pass all traffic without problem?  I've set both sides to
have an MTU of 1514, as the Linux box defaulted to 1480 ISTR, while the
Cisco defaulted to 1514.

-- 
                       /------------------------------------------------->
Marius Strom           | Always carry a short length of fibre-optic cable.
Professional Geek      | If you get lost, then you can drop it on the
System/Network Admin   | ground, wait 10 minutes, and ask the backhoe
http://www.marius.org/ | operator how to get back to civilization.
                       \-------------| Alan Frame |---------------------->