Locate the switchport where the host is connected to (Cisco CatOS and IOS)

In a forest of Cisco Switches, sometimes it is hard to locate which switch port the host/PC is connected to.  I have summarize the command needed to perform the task on a Cisco CatOS switch and a Cisco IOS switch.

1. Find the MAC address of the target PC first

C:\>ping pc-hostname

Pinging pc-hostname [192.168.11.49] with 32 bytes of data:

Reply from 192.168.11.49: bytes=32 time<1ms TTL=128

Reply from 192.168.11.49: bytes=32 time<1ms TTL=128

Ping statistics for 192.168.11.49:

    Packets: Sent = 2, Received = 2, Lost = 0 (0% loss),

Approximate round trip times in milli-seconds:

    Minimum = 0ms, Maximum = 0ms, Average = 0ms

Control-C

^C

C:\>arp -a | findstr "192.168.11.49"

  10.68.11.49           00-aa-bb-cc-dd-ee      dynamic

2. CatOS: find the connection port

C:\>telnet my_sw1

  

Cisco Systems Console

          Welcome to MY_SW1

 Enter password:

MY_SW1> en

Enter password:

MY_SW1> (enable) show cam 00-aa-bb-cc-dd-ee

* = Static Entry. + = Permanent Entry. # = System Entry. R = Router Entry.

X = Port Security Entry $ = Dot1x Security Entry

VLAN  Dest MAC/Route Des    [CoS]  Destination Ports or VCs / [Protocol Type]

----  ------------------    -----  -------------------------------------------

3     00-aa-bb-cc-dd-ee             3/8 [ALL]

Total Matching CAM Entries Displayed  =1

MY_SW1> (enable) show cdp neighbors 3/8

* - indicates vlan mismatch.

# - indicates duplex mismatch.

Port     Device-ID                       Port-ID                   Platform

-------- ------------------------------- ------------------------- ------------

 3/8     MY_SW7                         GigabitEthernet0/1        cisco WS-C3560-24TS

MY_SW1> (enable)quit

3. The PC is connected at MY_SW7.  Let's go to MY_SW7 to find the exact port:

C:\>telnet my_sw7

  

User Access Verification

Password:

MY_SW7>en

Password: Welcome to MY_SW7

MY_SW7#show mac-address-table address 00-aa-bb-cc-dd-ee

          Mac Address Table

-------------------------------------------

Vlan    Mac Address       Type        Ports

----    -----------       --------    -----

   3    00aa.bbcc.ddee    DYNAMIC     Fa0/13

Total Mac Addresses for this criterion: 1

MY_SW7#show interfaces Fa0/13

FastEthernet0/13 is up, line protocol is up (connected)

  Hardware is Fast Ethernet, address is 00ff.eedd.bbaa (bia  00ff.eedd.bbaa)

  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,

     reliability 255/255, txload 1/255, rxload 1/255

  Encapsulation ARPA, loopback not set

  Keepalive set (10 sec)

  Full-duplex, 100Mb/s, media type is 10/100BaseTX

  input flow-control is off, output flow-control is unsupported

  ARP type: ARPA, ARP Timeout 04:00:00

  Last input never, output 00:00:01, output hang never

  Last clearing of "show interface" counters never

  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

  Queueing strategy: fifo

  Output queue: 0/40 (size/max)

  5 minute input rate 50000 bits/sec, 11 packets/sec

  5 minute output rate 125000 bits/sec, 19 packets/sec

     17009916 packets input, 2224460537 bytes, 0 no buffer

     Received 49139 broadcasts (0 multicast)

     0 runts, 0 giants, 0 throttles

     1 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

     0 watchdog, 28 multicast, 0 pause input

     0 input packets with dribble condition detected

     53834839 packets output, 3153486266 bytes, 0 underruns

     0 output errors, 8 collisions, 2 interface resets

     0 babbles, 35 late collision, 0 deferred

     0 lost carrier, 0 no carrier, 0 PAUSE output

     0 output buffer failures, 0 output buffers swapped out