Find MAC of PC plugged into IP Phone - detective work

FuturaFutura Member Posts: 191
When I do a 'Sh Mac-Address-Table dynamic' of course it shows me the same mac for the Data and Voice VlAN because the phone is a trunk agreed, So All I want to do is find out if a computer is plugged into the second port of a phone and what the MAC address is. This must all be done from the switch itself. Walking round a building is not an option for me cause of locked doors etc.

Many thanksicon_cheers.gif


  • networker050184networker050184 Mod Posts: 11,962 Mod
    If a PC is attached to the phone you should see it's MAC address for the data VLAN, not the phones. Same as any switch it should not substitute it's own MAC for the end devices.
    An expert is a man who has made all the mistakes which can be made.
  • TrifidwTrifidw Member Posts: 281
    If the voice vlan is 10 and data 20 you should see these entries when doing a show mac-address-table

    10 - phone mac
    20 - phone mac
    20 - PC mac
  • kmcintosh78kmcintosh78 Member Posts: 195
    NMAP or Superscan may provide you with the info you are looking for.
    What I am working on
    CCNP Route (Currently) 80% done
    CCNP Switch (Next Year)
    CCNP TShoot (Next Year)
  • FuturaFutura Member Posts: 191
    So your saying that If there is a PC connected to the phones switch port the mac will show up in correct data vlan that it is attached to?

    So maybe there is no PC connected to the phone, because if I do a sh mac-address-table dynamic I get the same mac address for the VLAN 2 = Data and VLAN 50 = voice and that is all.

    I will lab this up to be sure but many thanks for the input.icon_cheers.gif
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