[SOLVED] How do you tell which switchport this is connected to?

szboardstretcher · 03-31-2011, 11:52 AM

Noticed that ESXi and such, are able to tell which switchport they are plugged into.

How, in Centos, from the commandline, could I tell which switchport it is plugged into?

szboardstretcher · 03-31-2011, 01:22 PM

Ill answer my own question. There are two options.

http://sourceforge.net/projects/cdpr...4/cdpr-2.4.tgz

Download that, install libpcap-devel and compile and run it.

Or run this simple tcpdump command

Code:

tcpdump -nn -v -i eth0 -s 1500 -c 1 'ether[20:2] == 0x2000'

Which will listen long enough to capture one CDP packet and display its info.