Trace Route Doesn't Return DNS Name

[patrick.hurley]

I changed from a Linksys E4200 to a 5505 and when I use trace route, it doesn't return a DNS name for each hop.   I can see the hops shown as asterisks.  Do I have to add something to inspect for this to work?                  

[Jouni Forss · Accepted solution]

Hi,

You could try the following. (Depending if your "policy-map" configuration is as its default settings)

policy-map global_policy

class inspection_default

  inspect icmp error

  inspect icmp

Then you could add the following to your ACL attached to your "outside" interface or configure a new ACL to your "outside" interface if it doesnt yet exist

access-list OUTSIDE-IN remark Allow ICMP return messages

access-list OUTSIDE-IN permit icmp any any unreachable

access-list OUTSIDE-IN permit icmp any any time-exceeded

access-list OUTSIDE-IN permit icmp any any echo-reply

access-group OUTSIDE-IN in interface outside

You will naturally use the existing ACL if you have one. If no ACL exists you can use the above configuration as it is.

Hope this helps

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- Jouni