"If you use your laptop in many different locations, you must be
tired of having to configure your network manually every time.
Dynamic Host Configuration Protocol (DHCP) is a nice alternative,
but what can you do in places where DHCP is not an option. Guessnet
is the right tool for that job.
"As its name implies, Guessnet tries to guess the network you
are connected to based on a list of candidate profiles and a test
pattern for each one. To make a long story short, it tries to match
the static IP of a host, usually a router or a server, with a
specific MAC address, which is unique for every network card. If it
succeeds, it prints out the name of the profile, and you can use
that to configure your Ethernet interface accordingly using a shell
script, or, if you use Debian (or any Debian-based distribution,
such as Ubuntu) directly from /etc/network/interfaces and ifupdown.
Other test methods that can be used are described in the guessnet
man page, but I prefer the IP-MAC matching method, because it's
easy to set up and just works..."