08-07-2006 05:48 PM - edited 03-03-2019 01:35 PM
Need help please. Have 5 Vlans on 2970 switch that is communicating with the 3750 L3 . On the 2970 I need to find out which PC/Computer is connected to lets say port 20 of the 2970. Since 2970 is a Layer 2 switch, how can I achieve my goal , I think MAC address is my answer but I need the IOS commands please. If you can think of some other utilities that would help I apperiaciate it very much. Thank you
08-07-2006 06:44 PM
Saied
I doubt that you will accomplish this with a single command or by anything on a single box. But I think that you could accomplish it by doing this:
- on the 2970 do show mac-address which should show the layer 2 forwarding table (what is refered to as cam on some other Catalyst switches). Look for port 20 and note the MAC address.
- on the 3750 do show arp and look for the MAC address. This should give you the IP address of the device on port 20.
HTH
Rick
08-09-2006 12:38 PM
Rick's right, you will need to chase this on both devices. Try this
2970 - sh mac-address-table interface fastEthernet 0/20
This should provide you with the MAC address. Use this address on 3750 as follows
sh ip arp | include xxxx.xxxx.xxxx
You should see host's ip address.
Slav
08-09-2006 12:45 PM
Also, using the mac address, you can search the OIU listing at
http://standards.ieee.org/regauth/oui/index.shtml
to find the maker of the device.
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