On Sat, Nov 1, 2008 at 9:48 PM, Dale Shaw <[EMAIL PROTECTED]> wrote:
> Hi all,
>
> Here's the scenario:
>
> - L2 switchport in cat3750 "up/up"
> - No MAC learnt on the interface ("sh mac-addr int gi1/0/4" shows no
> dynamic MAC address)
> - Attached device not necessarily configured with an IP in the correct
> VLAN (mismatched with switchport) - endpoint IP configuration unknown
>
> I haven't really given this much consideration, but does anyone know
> of any tricks, ideally executed _from_ the switch, to encourage the
> attached device to spit back a frame? Essentially I want/need to
> figure out what's attached. Even knowing the MAC vendor would help.
>
> Other suggestions are welcome. I guess I could try things like a
> broadcast ping from a host in the same VLAN, make the port a trunk and
> madly ping sweep, but something more elegant would be nice.
>
> A physical inspection, in this case, is not possible.Nothing elegant... You could always shutdown the port and wait for someone to complain. If it's not randomly generating traffic, then it's not a windows box. Switches tend to be noisy with layer 2 protocols. Firewall or UNIX/Linux based system? Does the duplex and speed show up as auto-negotiated (a-full, a-100)? You could try "no switchport" and the "ip add dhcp" on the interface to see if you can generate a response that way. Set an IP on the interface so that you can "ping 192.168.1.255 source ...". Pinging broadcast addresses might speed up the process. Setting up a SPAN or RSPAN might help you capture some traffic. "test cable-diagnostics tdr interface ..." would at least tell you how long the cable is. Setup the port as a trunk or port-channel or .... with auto-negotiation and see what happens. Set the switch up as a management cluster and then run "show cluster members". Use the other suggestions.... _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
