Device-to-Port Mapping - How?!

[enjay]

I could really use a way of identifying which switch ports all our devices (or rather, all our desktop PCs) are connected to. Any suggestions as to tools which can do this?

 

I have tried Spiceworks, but can't get it to inventory the devices fully enough for that, I think because I have an overly-zealous software firewall on all the PCs - hopefully that won't affect any other auditing tools...

[RichB]

Long way around it you could buy a Fluke tester that will tell you which network port the PC's are plugged into and its also a really useful bit of kit.

[siuko]

LanTopolog Automatic physical network topology discovery

 

Worked well for me

 

Edit: Just realised that isnt freeware anymore... search for Lantopolog 1.3.2 which is freeware and works fine

 

Edit 2 : Looks like softpedia have it > http://www.softpedia.com/progDownload/LanTopolog-Download-89837.html

Edited June 17, 2014 by siuko

[enjay]

LanTopolog Automatic physical network topology discovery

Thanks. That is finding the MAC addresses of the PCs, but not resolving their names. Can that be done, or will I need to manually cross-reference against DHCP?

[mikeyd101]

What switches do you have managed / un-managed?

 

I've recently been exploring this in our environment and discovered a couple of things that may help LLDP (link Layer discovery protocol) which on our extremes wasn't enabled by default but is industry standard. Also ARP tables should show you mac/ip and if your lucky port information.

 

If you happen to have extreme you can do:

 

show iparp

 

which shows ip, mac and port (but can display multiple devices on same port if there's another switch) also

 

show edp ports all

 

shows what other extreme switches are plugged into what port.

[enjay]

What switches do you have managed / un-managed?

HP Procurve managed switches, but it could be that they've had some standard features turned off. What settings should I be looking for?

[mikeyd101]

I'd start with telnet / shh session to the switch then:

 

show arp

 

that will give ip,mac and port and

 

show lldp info remote-device

 

This info is probably available through the web inferface also, i just prefer command line and possibly you might need to look at

 

show lldp config

 

if it doesn't work to enable it, looks like this show the neighbouring switches ChassisId, local and remote ports, that's what our E5406zl shows, also i think (not sure) that lldp will need to be enabled on the surrounding switches in order to talk lldp to each other.

 

I'm still trying to learn and figure this all out for myself so take the info with a large pinch of salt, it could be wrong. But it's help me slowly try and figure out our complex network spaghetti junction my predecessors left.