How to get MAC address with known IP address..

Posted on 2011-05-10
Last Modified: 2012-06-21
How do I get the MAC address if I have the IP Address; I am using a Cisco Cat 4500.
Question by:Qmez
    LVL 24

    Accepted Solution

    ok so if the 4500 has an IP address on the same network as the device you are trying to find, you can do the following assuming you are running IOS on the 4500.

    From the 4500 ping the IP address of the device you want.

    Let say it was

    Then issue this command

    sho arp | in
    LVL 24

    Assisted Solution

    by:Ken Boone CCIE #4649
    You can also do this from your PC if you are on the same IP network as the device you are trying to reach.

    Ping the device and from the CMD prompt type
    arp -a

    That will show you also.
    LVL 6

    Expert Comment

    If you dont have a layer 3 interface configured on the same Vlan, you wont be able to have output for the show arp command
    you can configure a layer 3 address (interface vlan) in the same  vlan on the switch, or stick to use the show mac-add command which associates a mac  to an interface

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