[c-nsp] Hiding a Cisco Router from a Traceroute

[John Kristoff]

On Thu, 20 Oct 2005 17:12:37 +0000
Kristofer Sigurdsson <kristo at ipf.is> wrote:

> Here's how traceroute is done:
> 
> The host sends a UDP packet on port 33435 to the host he's 
> traceroute'ing to, with a TTL of 1.

You can effectively do a traceroute using any IP protocol and Windows
by default uses ICMP echoes.

I thought someone pointing out that MPLS can hide the topology was
interesting.  That would have to be one of the most peculiar reasons
for implementing MPLS though.  :-)

I agree with the sentiment expressed in the note I'm replying to that
blocking it is of dubious merit.  Hoewver, if you insist, rather than
a router ACL you probably want to look at a more sophisticated firewall
solution.

John