Wireshark-users: [Wireshark-users] Vanishing interface

From: M K <gedropi@xxxxxxxxx>
Date: Sun, 23 May 2010 09:22:06 -0700
Currently I am using this low-end machine (Windows 2000 OEM, dial up)
for passive monitoring to debug application, firewall, security and
LAN issues via the generic adaptor & the WAN (PPP/SLIP) interfaces
working in tandem.  This has worked very well.  Or, at least, until
yesterday.

Yesterday, somehow I lost the WAN (PPP/SLIP) interface.  Without that
interface, there was no capturing - unless one performs the
installation of the virtual loopback adapter.

Here is what I did.  When the WAN interface vanished yesterday, I
attempted to restart the box and then log on with WS.  No Wan
interface.  Today I booted up and again started up WS.  Today both
interfaces were back.

Here's my question:  Why did I loose the interface in the first place?
 Since this interface originates from the WAN (for which I have no
visibility) could this be a DCHP lease issue or an ACL issue or ?

Many thanks.