Date : Sat, 11 Mar 2006 00:44:43 GMT
From : Pete Turnbull <pete@...>
Subject: Re: Them pesky case stickers (was 1MHZ SCSI/ATA board.)
On Mar 10 2006, 12:16, Jules Richardson wrote:
> philip pemberton wrote:
> > What about tracerouting the machine?
>
> Hmmm, not sure - we were primarily on token ring (better performance
under
> load and yadda yadda) so I don't know if it'd work there.
>
> I suppose for Ethernet it'd be enough to pin down which segment a
machine was
> on...
You wouldn't use traceroute, it would only tell you what subnet the
machine was on. Most LANs only have one or two. You want something
like switch digger (http://sdig.sourceforge.net/ ) which tracks MAC
addresses to switch ports. Then if you have a database showing what
wall sockets the switch ports are patched to you can locate things
easiliy and quickly. You don't even need the database if you can
easily go and look at the switch ports and physicaly trace the cables.
You do of course need managed switches to do this, but no network of
any size ought to be using unmanaged switches.
You don't even really need sdig. We track machines for various reasons
by hand. ping the target, check the ARP table to get the MAC address
if we don't already know it, and look that up in the forwarding
database of the nearest switch. That gives us a port number; if there
are other addresses on the port it means it's connected to another
switch or hub, so repeat the process on the other switch. sdig merely
automates that process (once you tell it how your switches are
interconnected).
> I suppose for Ethernet it'd be enough to pin down which segment a
> machine was on...
Well, yes, because strictly speaking a segment is (at most) a single
switch port :-) But I doubt that's what you meant. I think you meant
a subnet, and that probably isn't helpful unless you have a very finely
subnetted network.
--
Pete Peter Turnbull
Network Manager
University of York