[c-nsp] Disable some routing

[Pete Templin]

Bernd Ueberbacher wrote:

> You understood it right, this is exactly what I was looking for :-)
> ACLs were on my mind, but first I thought of something different (VRF as
> you wrote). After looking at the pros and cons I decided to use ACLs.
> There are a few reason that stand for it, instead of using VRF. In my
> scenario ACLs would be way enough and VRF could be overkill for this
> small configuration.
> 
> An other reason is that I don't want to implement something that I don't
> really know. I hope it's not a shame if I say that I never used VRF
> before. I'm young! :-p

Don't be "skeered" of VRFs - they're incredibly simple.  Although part 
of MPLS functionality, I/we got our introduction to them in a single 
router configuration.  Just create the VRF ('ip vrf <NAME>'), put your 
interfaces into the VRF ('ip vrf for <NAME>' before you 'ip addr'), put 
your static routes into the VRF ('ip route vrf <NAME> blah blah blah'), 
and troubleshoot in the VRF ('sh ip ro vrf <NAME>', 'ping vrf <NAME> 
blah', 'traceroute vrf <NAME> blah', 'telnet blah /vrf <NAME>', etc.).

pt