procedure to find port by ip arp mac
Assumptions:
You have an IP address and want to find out what switch port it is on.
There is a core switch with edge switches and Cisco CDP is running.
Example: IP address is 10.1.1.69
– find the MAC address of this IP
open ssh console to core switch and run “sh arp”
coreswitch#sh arp | inc 10.1.1.69
Internet 10.1.7.69 0 0007.1234.cd43 ARPA Vlan5
– find port from MAC address
coreswitch#sh mac-address-table dynamic | inc 0007.1234.cd43
* 5 0007.1234.cd43 dynamic Yes 5 Gi7/12
– find edge switch for port
coreswitch#sh cdp nei gi7/12
Capability Codes: R – Router, T – Trans Bridge, B – Source Route Bridge
S – Switch, H – Host, I – IGMP, r – Repeater, P – Phone
Device ID Local Intrfce Holdtme Capability Platform Port ID
edgeswitch.company.net
Gig 7/12 176 S I WS-C3560G-Gig 0/49
– open ssh console to edge switch and run “sh arp” repeat process