A script to run a quick network device inventory
Wed, Oct 13 2004 at 9:45AM PDT • Contributed by: MartySells
Wed, Oct 13 2004 at 9:45AM PDT • Contributed by: MartySells
I've written a script that I call netinv which uses the ARP cache to identify devices on the network segment. For each device, it looks up the vendor name based on the MAC address and also tries to get the remote system's netbios name. For small (i.e. home) networks, the vendor and netbios name are usually enough to remind you what a particular device is.
To use it, start by downloading the script from my page; you can do this in the Terminal by typing:
Sample Output:
To use it, start by downloading the script from my page; you can do this in the Terminal by typing:
curl -O 'http://www.studiosells.net/msells/netinv'Sample Output:
$ ./netinv IP MAC DNSname NBname Vendor ---------- ---------- ---------- ---------- ---------- 192.168.3.1 0:a0:c5:e2:4a:16 ? ZYXEL COMMUNICATION 192.168.3.3 0:0:39:8:4:1a ? PIZZA TOSHIBA CORPORATION 192.168.3.4 0:4:e2:52:4e:11 dell CANADA SMC Networks, Inc. 192.168.3.40 0:50:e4:99:2c:39 meatloaf MEATLOAF APPLE COMPUTER, INC. 192.168.3.52 0:b:db:a7:4c:5 ? STACY Dell ESG PCBA Test 192.168.3.60 0:4:76:da:47:1d dell DELL 3 Com Corporation 192.168.0.110 00:03:93:bf:17:c0 eyeBook EYEBOOK Apple Computer, Inc. 192.168.3.200 0:3:93:bd:26:1e fatmac FATMAC Apple Computer, Inc.Notes:
- Since this works from your ARP table it will only include hosts that you've ARPed for:
- The host you run it on will not be included. I considered this a big enough non-feature that you can specify the -l option to have the the local system included. The code for doing this is quite sketchy, but I didn't want to add more module requirements.
- You can ping hosts to get them added to your ARP table, or one way to quickly populate is to do a scan of some sort.
- Assuming you have nmap installed, just do nmap -sP 192.168.0.0/24
- If you don't nave nmap, here's a slower method:
Note that port 22 does not have to be open on the system. I just found that using nc was faster than using ping -c 1.perl -e 'for $i (1..10) { system qq!nc -z -w 1 192.168.0.$i 22!; }' - There are command line options to disable the vendor and netbios lookups, as well as to produce non-justified tab separated output without the header. See netinv -h for details.
- If you don't have the Perl module Net::MAC::Vendor, then netinv will use a built-in vendor lookup that seems to work OK, but is probably not as robust. Try installing the module with perl -MCPAN -e 'install Net::MAC::Vendor'. There's also a web page where you can do MAC-to-vendor lookups.
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