Network Assessment?

Nagios and VISIO has some facilities to map out your LAN..

Probably could use something like SNORT for intrusion detection and WireShark to get you started..

HTH,

Kent

however you can only scan devices on the subnet you are connected to.. if there are vlans or firewalls you typically cant scan past them, and need to physically connect to other parts of the network.

This is the purpose of those firewalls and vlans etc. eg you cant scan the entire internet - and you certainly cant scan from the internet into my network.

Great posts guys.  A few tools I knew of and some I did not but now do.  Thanks for the feedback.

I think I have a better description for what I need.  I may have not enumerated on what I wanted exactly.

I am on a workstation in this network I need to scan.  I want to find out every piece of equipment I touch on the way to the Internet.  Some are switches and appear transparent.  How do I find this info?  Brands, models, etc.  Thanks.

In that case, the quick, cheap and dirty would be Advanced IP scanner.  It will tell you everything on the same subnet.  

But unfortunately the switches might be on their own VLAN, which will not show up on your scan as wolfcamel stated.  If they have an IP on the same subnet, it will show up.  If they haven't been setup at all (which many times I see) or if they are and you have no admin credentials then you may have to do a console session.