Track/Locate a Switchport Using a Know IP Address

IP Address to Track/Locate: 115.116.7.44

1> Login to Gateway (Router)
ssh <router IP e.q: 115.116.7.1> = Hostname “SARISA”    
note: use PuTTY or alternative

2> Find out Mgt/VLAN of the given IP address
SARISA# show ip interface brief | exclude unassigned
Interface              IP-Address      OK? Method Status                ProtocolVlan77                  115.116.7.3     YES NVRAM  up                    up

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

3> Ping IP with source VLAN
SARISA# ping 115.116.7.44 source vlan77
or
SARISA# ping 115.116.7.44 source 115.116.7.3

Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 115.116.7.44, timeout is 2 seconds:Packet sent with a source address of 115.116.7.3
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms

4> Get MAC address using ARP
SARISA# show arp | include 115.116.7.44
Internet  115.116.7.44            1   0006.f62b.2545  ARPA   Vlan77

5> Get swport using MAC address
SARISA# show mac address-table | include 0006.f62b.2545        
3 0006.f62b.2545  dynamic  Yes      195     Te3/4

6> Verify port config, looking for ACCESS configuration
SARISA# show running-config interface Te3/4
Building configuration…
Current configuration : 105 bytes
!
interface TenGigabitEthernet3/4
switchport
switchport mode trunk
end

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
STOP if ACCESS config / CONTINUE if TRUNK config
YOU FOUND YOUR PORT  /    CONTINUE DIGGING !!
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

7> Get hostname of the next hop device connected to the TRUNK
SARISA# show cdp neighbor
Capability Codes: R – Router, T – Trans Bridge, B – Source Route Bridge
                  S – Switch, H – Host, I – IGMP, r – Repeater, P – Phone,
                  D – Remote, C – CVTA, M – Two-port Mac Relay
Device ID        Local Intrfce     Holdtme    Capability  Platform  Port IDohyaUNI.macmehappy.com                 Ten 3/4           146             R S I  WS-C6509- Ten 3/4

8> Get the IP address of the next hop hostname, in step 7
SARISA# show cdp neighbor detail | begin ohyaUNI.macmehappy.com
Device ID: ohyaUNI.macmehappy.com
Entry address(es):
  IP address: 115.116.7.2
Platform: cisco WS-C6509-E,  Capabilities: Router Switch IGMP
Interface: TenGigabitEthernet3/4,  Port ID (outgoing port): TenGigabitEthernet3/4

REPEAT Step 3 to 6, this time using Step 8’s IP address & Hostname!

END if this is an access port or BACK-TO-STEP-7  if this is a trunk port

#itMACmeHappy