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Community Member

VLAN CONFIGURATION

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

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Re: VLAN CONFIGURATION

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

Community Member

Re: VLAN CONFIGURATION

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

Community Member

Re: VLAN CONFIGURATION

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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