Finding Mac address on network

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03-26-2008 08:54 AM - edited 03-05-2019 09:59 PM
At my layer 3 switch I do a "show arp | in 192.168.0.X" and it comes back with a mac-address matching up with this ip, but when I try run a "show mac-address address" to find where this device is known on the network it doesn't register in the table. I went through all layer 2 switches, with the same result. Any ideas on how I can find this device?
L3 3750
L2 3550-35560
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03-26-2008 09:01 AM
did you verify that what is in the arp cache is current? Verify you can ping the IP you are looking for because it quite possibly could have aged out.
Sh mac-add | inc .xxx
is the best way i know of to trace a MAC through a network

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03-26-2008 09:04 AM
Hi Matt,
Thanks for the reply, this is a pingable address.
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03-26-2008 09:14 AM
sho mac-add is case sensitive.
Do a "sho mac-add | inc xxx" and see what your output is. The last 3 of the hex MAC is case sensitive so put exactly what you find on a sho arp.
