Another thing that's been bugging me for a while on the tech side of
things at home is my router. It's a Zyxel 2602 and while the interface
is shiny and the setup is fairly easy, the damn thing has a tendency to
atrophy and die after some days of uptime ... if there's been quite a
bit of traffic going through it. In the spirit of new
energy I wanted to do
something about it.
Now, although I'm clearly a geek and like my gadgets, I'm not loaded
with money, so buying a new shiny toy is not an option. Apart from that,
I have a hard time accepting that it shouldn't be possible to make the
Zyxel do the job properly. Well, maybe not properly - I have no
intension of messing with the firmware (apart from updates whenever
one's available/needed).
No, what I had in mind was scripting the router to reboot regularly. As
I've just moved my company site off the server at home there's no
problem if the router goes down for about a minute a day, in the middle
of the night. So the question became one of: how to script it?
Possible Solution 1
I've been using Selenium for various projects,
testing frontends and general functionality. Selenium allows you to
script actions and it's basically ideal for a task like this: log into
the webclient, find the right tab, click the right button, done.
Only problem is that installing this to run headless on my server every
night means installing SeleniumRC and various other things ... in short,
much too much work for just scripting a router reboot. If I already had
Selenium installed there, then no problem - but unfortunately I don't.
Possible Solution 2
Instead of installing Selenium, one could also give wget a try -
installing is a simple
sudo apt-get install wget
if the program isn't already installed, that is. After that, toying with
various command line options got me logged into the routers webclient
and requesting the reboot ... but no dice. For anyone interested, the
options you'll need are
- --save-cookies file / --load-cookies file
- --keep-session-cookies
- --post-data='blah=blah&moreblah=moreblah'
It didn't particularly look as if Zyxel actually cares about the
cookies, but you never know if they'll come in handy later.
Possible Solution 3
At this point I started looking for alternative ideas - and that's when
I remembered that Zyxel routers provide quite a few different protocols
for access (like most other routers). So I checked out the telnet
interface and quickly found myself wondering exactly what was going on
... the only help provided is lists of commands. No description, no
anything. In my battle to find out how to reset things, this led me
among other things to a factory reset of settings ... fairly annoying
(don't issue sys default unless you've got settings backed up!).
However, googling for info on Zyxel routers finally led me to a pdf with
some goodies, although for a different model. It was worth a shot
though, as the command looked as if it might work - and indeed, the
Zyxel 2602 will happily respond to a sys reboot issued over telnet.
That meant the task was down to scripting telnet - which turned out
quite easy. Here's the oneliner I ended up with
(cat /path/to/passwordfile; sleep 1; echo sys reboot; sleep 1) | telnet 192.168.1.1
The first bit echoes the details needed for the router - after the pipe
there's the actual connection. The sleep commands are there to allow the
router to echo back a response before reacting on it - without them you
wouldn't do anything. To avoid having the password stored in the shell
history I use a file for storing it in ... not that much more secure,
but at least you don't get surprised by where it moves to.
Done
A little bit of researching, some vim'ing and there: a script to restart
my router every night at 5. Only thing left is scheduling the cron job
:)