Dead gateway detection

C. Ed Felt ed at
Wed Apr 13 10:51:50 MDT 2005

Gabriel Gunderson:

I wrote a Python script (soooo much easier than perl :-) ) that uses 
ping but also has a backoff algorithm built in, (only does what it needs 
to on a 1, then 5, then 10 etc. on up to 40 min. interval).  I also just 
use cron to run the script every minute.  With an RPS-10 (about $90) 
hooked to the COM port on the server, it actually reboots the DSL Modem 
if the ping fails via an expect script.  I also have cron save a log 
file (with ">>") each time so we can look back and see if and when the 
connection is going down.  If I had time I would probably update it to 
use a databse.  If you wanted to watch for a dead gateway in real time, 
you would just have to put what I have done in a while loop and run it 
(no cron).  In short, ping is the only way I know of to watch for a dead 
gateway, unless you want to so some SNMP level programming, (which 
Python has a module for).

Let me know if you would like me to send it to you,


I have some asterisk questions, (IPCentrex, Voice Mail, Call routing, 
H323<-->SIP translation etc.), any Asterisk experts out there?

Gabriel Gunderson wrote:

>I'm setting up a box with two connections going out to different ISPs
>for a small business in town.  The second was just for a backup but they
>wanted to be able add its bandwidth to that of the first for out going
>traffic.  On a failure the traffic goes out the one connection.
>I think I have it all working but I'm still looking for an elegant way
>to detect a dead gateway.  I have a cron job that uses ping to check
>each gw.  It works but it's a little clunky and only checks every
>What have you all done to detect dead gateways?
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