cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
Announcements
configure & troubleshoot anyconnect
3581
Views
0
Helpful
3
Replies
Beginner

Unknown traceroute response message

This is a real trivial question; has anybody come across ICMP reply message !X when tracing from a Linux box to a cisco device?

---unfortunatelly I have no visibility\Access of the Cisco box---

Does someone know what it means, this reply ICMP symbol is not in the normal cisco list.

3 REPLIES 3
Beginner

Re: Unknown traceroute response message

This is a UNIX specific code, it should carry the same meaning of !A in Cisco, which means that Communication administratively prohibited. The network administrator has blocked traceroute at this router using something like Access-list for example.

Beginner

Re: Unknown traceroute response message

Thanks a lot, indeed it's a filter, that was my first thought anyways,

Tony

Beginner

Re: Unknown traceroute response message

One more thing.. here are the list of traceroute codes that you can see in a UNIX box,

!H

Host unreachable. The router has no route to the target system.

!N

Network unreachable.

!P

Protocol unreachable.

!S

Source route failed. You tried to use source routing, but the router is configured to block source-routed packets.

!F

Fragmentation needed. This indicates that the router is misconfigured.

!X

Communication administratively prohibited. The network administrator has blocked traceroute at this router.

Sometimes, with some versions of traceroute, you will see TTL warnings after the times. This merely indicates that the TTL value on the reply packet was different from what was expected. This probably means that your route is asymmetric.