Network Device Finger Printing
Sometimes I lose track of all the devices on a network and need a reminder of everything that is there. Under IPv6, you won’t scan the entire subnet – it would take millions of years – but under IPv4, you still use a scan. nmap is good for this and running it with operating system finger printing goes quickly (relatively speaking).
nmap OS finger print command
$ sudo nmap -O 192.168.0.0/24
- the -O above is an “oh”, not a “zero”.
- root/Administrative privilege is required for this to work.
- nmap is cross-platform. It is available for all the popular platforms – it even runs on my Nokia N800.
Save the Output to a Log File
You may want to save the output even if you have just a few devices to scroll back and read it easily. It goes by too quickly.
$ sudo nmap -O 192.168.0.0/24 | tee log
This tip fits with the tip to User a Router to Centralize Your Network Device Management from earlier this week.
GUI – Zenmap
If you prefer GUI interfaces, there’s a GUI for nmap called zenmap. If you load that tool, after running the scan, be certain to check out the topology tab for a visual representation of your network. Get it. Zenmap is available for most popular platforms too, including the N800.
