Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

cisco 2801 router,

This question came from our CSC Facebook community.

dear  need help  when i use the command on cisco 2801 router #show ip aliases  Address Type             IP Address      Port Dynamic                       this is the reply i m getting but i cant find the ip address on any of  the router interface nor on clients  i want to know how to remove this  ip  but i can ping this ip  its of the subnet
Cisco Employee

Re: cisco 2801 router

Dynamic ip alias is created by the router for nat translations.  It allows the router to respond to arp requests for IP addresses not physically configured on the router.

For example you may have something like

ip nat inside source static

you could also have this overloaded using a acl or as part of a pool.

The only way to get rid of this dynamic entry would be to remove the configuration that would cause it to be added.  Check your config for nat pool or nat statement that would contain this address or the subnet it would belong to.


David Aicher

New Member

Re: cisco 2801 router

I checked all 6 routers for this possible ip address and nat configuration , but it was in vain.

is there any aother possibility. pls help

Cisco Employee

Re: cisco 2801 router

On the device that reports that address capture the following

show ip nat translation | inc

show run | inc  10.221.125

for that address to show up in "show ip alias" it has to be in some config on that router.


Dave Aicher