Catalyst Port Question?

[RNBradyIII]

Hello,

I need to discover an IP address for a device on a specific port(FastEthernet1/0/2 on a catalyst 3750. The switch and the patch panel are not labeled so I have no clue which devices are where. Is there a way to do this?

Thanks

Rich B.

[sstudsdahl]

Rich,

If you look at the output from the command "show arp", you should be able to get the IP to MAC address information. Then use the command "show mac-address-table address ". This will then map the MAC address to the specific switchport.

You can also use the "show mac-address-table interface " command to get the MAC address initially and then map it to an IP address from the ARP table.

Steve

[vantipov]

Steve,

I used your suggestion and what I get is blank info. I am using Cat2950 and when I do show mac-address-table address I get the following:

Mac Address Table

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

Vlan Mac Address Type Ports

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

host#

Any sugestions?

[Richard Burts]

Is there any possibility that you had a keystroke error in entering the MAC address? Is there a possibility that you did not format the MAC address in the way that the switch expects?

Depending on the number of entries in the switch MAC address table, you might try the command show mac-address-table without specifying the address. This will display all entries in the table and perhaps then you can find the one that you are looking for.

HTH

Rick

[amikat]

Hi,

This comes from Cat2950 docs:

Beginning with Cisco IOS Release 12.1(11)EA1, the show mac address-table command replaces the show mac-address-table command (with the hyphen).

Best regards,

Antonin

[dave.keith]

Learned MAC addresses in forwarding tables and IP/MAC pairings in ARP tables time out. So it might be that the device has been quiet for a while. To handle that you might want to use an automated tool to periodically collect MAC/Port info from switches and ARP tables from routers and correlate the two into a report. See www.kiwisyslog.com for CATTools, which does this very nicely.

Dave

[vantipov]

Dave,

Kiwi is working for me. Thanks a lot for your help.

Vlad