I used to have this application on my Windows computer that could scan the network and identify all devices via level 2 and level 3 scanning. I initially learned about it at a SANS conference. The problem is, NMAP and ZenMap don't seem to show the network switches that I know are on my network. I'm looking for suggestions on a free utility that can perform this type of scanning and provide a detailed map of both TCP/IP level 2 and 3 addresses. Any ideas?
5 Answers
It’s important to note that unmanaged switches won’t show up in scans since they operate at layer 1. If NMAP isn’t detecting your switches, make sure they’re managed types; those should definitely appear on your scans.
You could try using NMAP along with arpwatch. If you're patient, you can capture MAC addresses by just listening for a while. You might even get them from the managed switches on your network.
Netdisco is another solid option. It tends to give nice insights about what devices are on your network. Have you given it a shot?
I’ve used Advanced IP Scanner before, and it’s pretty reliable. There are definitely better tools out there too, but for free, it gets the job done!
You might also want to check out Lantopolog. They have a low-cost license, and it’s pretty useful for mapping out your network. Here’s their download page if you’re interested!
Thanks for pointing that out. That makes sense! I should check which type of switches I have in my setup.