If you do not have a cdp command available on your linux server, then tcpdump can be used instead. $ sudo tcpdump -nn -v -s 1500 -c 1 ‘ether[20:2] == 0x2000’ -i eth0 tcpdump: listening on bond1, link-type EN10MB (Ethernet), capture size 1500 bytes 08:53:01.946674 CDPv2, ttl: 180s, checksum: 692 (unverified), length 254 Device-ID (0x01), […]