Generate a vtund.conf on the fly to match changing network conditions.
you’ve just come from the
previous hack [Hack #98], then this script will
generate a working
vtund.conf for the client side automatically.
If you haven’t read the previous hack (or if
you’ve never used vtun), then go back and read it
before attempting to grok this bit of Perl. Essentially, it attempts
to take the guesswork out of changing the routing table around on the
client side by autodetecting the default
gateway, and building the
To configure the script, take a look at the
section. The first line of
the addresses, port, and secret that we used in the vtun hack. The
second is there simply as an example of how to add more.
To run the script, either call it as
vtundconf home, or set
$TunnelName to the one you want to default to. Better
yet, make symlinks to the script like this:
ln -s vtundconf home#
ln -s vtundconf tunnel2
then generate the appropriate
calling the symlink directly:
vtundconf home > /usr/local/etc/vtund.conf
You might be wondering why anyone would go to all of the trouble to
make a script to generate a
vtund.conf in the first place. Once you get the settings
right, you’ll never have to change them, right?
Well, usually that is the case. But consider the case of a Linux laptop that uses many different networks in the course of the day (say, a DSL line at home, Ethernet at work, and maybe a wireless ...