Solved: Traceroute ....

InternetB · ‎11-18-2008

Hi,

I have a question with regards to traceroute ... When I do a traceroute, at times I see something lke this ...

1 10.10.10.10 4 msec 0 msec 4 msec

10.10.10.11 4 msec 0 msec 4 msec

10.10.10.10 4 msec 0 msec 4 msec

2 10.10.11.1 0 msec 0 msec 0 msec

10.10.11.2

10.10.11.1

3 172.31.2.4 16 msec 4 msec 8 msec

My questions is why are we seeing 3 IPs like in the 1st hop ? What does it mean ?

Thank you,

Cheers,

- InternetB -

Jon Marshall · ‎11-18-2008

You will see this when the router has multiple paths to the same destination.

So if you log onto the first hop router and and do a "sh ip route" you should see 2 next-hops for the destination IP address you are tracerouting to.

Jon

Jon Marshall · ‎11-18-2008

You will see this when the router has multiple paths to the same destination.

So if you log onto the first hop router and and do a "sh ip route" you should see 2 next-hops for the destination IP address you are tracerouting to.

Jon

royalblues · ‎11-18-2008

Just to add to Jon's post that this will be the case only when you try to trace from a cisco device and not from a desktop.

This is because the packets originated from the cisco device are process switched and hence the 3 trace probes are sent in a loadbalanced fashion.

Trace packets from a desktop would be CEF switched to a flow path already established and will not exhibit this behavior

Narayan