Show IP connected to Port ??

[william2u]

hi guyz, is ther a command in cisco to show the ip address connected to a particular port ???

For example, PC A 10.1.1.1 connected to FE0/1.

Command to show 10.1.1.1 connected to Fe0/1....

[ankurbhasin]

Hi William,

There is no direct way to find that out i.e no direct command.

But what you can do is on layer 3 device you can run a command "sh ip arp 10.1.1.1" and find the mac address for that ip.

Then go to the switch and run the command

"sh mac-address-table address " and you will get a port number.

HTH, if yes please rate the post.

Ankur

[royalblues · Accepted solution]

I dont think there is any direct command that will give you the ip address connected to a particular port

If the Ip address are in the same broadcast domain, u can use arp and the Mac address mapping to get the port it is connected to

eg..

ms_mla_mgmt_14dc#sh ip arp

Protocol Address Age (min) Hardware Addr Type Interface

Internet 172.16.102.246 7 0002.e355.0b6e ARPA VLAN1

Internet 172.16.102.88 0 0009.6bb7.d330 ARPA VLAN1

ms_mla_mgmt_14dc#sh mac-address-table address 0002.e355.0b6e

Non-static Address Table:

Destination Address Address Type VLAN Destination Port

------------------- ------------ ---- --------------------

0002.e355.0b6e Dynamic 1 FastEthernet0/21

ms_mla_mgmt_14dc#

ms_mla_mgmt_14dc#

[GRAEME DANIELSON]

If your setup is reasonably modern try L2 traceroute...

"traceroute mac ip "

automagically uses dns, arp cache, cam table and cdp in one hit - as long as the tables are populated. And sometimes you don't even have to be on one of the end switches. Nice command.

oops.. yep forgot to mention both ends need to be in same VLAN/subnet. So if you just want to find info for one IP use it's default gateway as the other IP. Happy documenting (: