new impenitrable workgroup on network

[Jimbo]

Hi, I run a small network and recently have setup a vpn between our sites.
The new workstations were added (to net neighborhood) plus a new workgoup
appeared "Tant-a01" which seems to have a single workstation attached. The
problem is; I cannot account for this extra workgroup as it doesnt belong
to any of my networks.

So when I disconnect the VPN's, my network goes back to displaying the
regular PC's ON the subnet, but even after several hours the "Tant-a01"
workgroup (which I cannot account for anyway) remains.

So my question: Do I have a security issue, or is this some kind of network
weirdness?

 

[Roger Abell]

What shows in the browselist are machines active
on the network segment, although once they become
inactive it can take some time for them to age off of
the list.
Try at a cmd prompt issuing
nbtstat -n
to see if it has been in communications recently (or you
with it)
Try
ping -a <name of machine>
to see if you can get its IP returned.