Being sent IP of eth0 when it changes???

[slewis1972]

I use the dyndns.org and the webmin module to update it when my ip changes onmy Redhat8 server. I ahve been finding that this is failing - it cannot connect to dyndns.

What i would like to do while I fix the above is get a email sent me at x address when the ip address of eth0 changes.

The thing is - i have not a clue on how to do it.
Otherwise, I could always setup a cron job to email me the ip every hour.

Can anyone help?

Scott

[Alex Cavnar, aka alc6379]

Yes, you could, actually.

Just set the crontab job to run

ifconfig eth0 > ~/ip_addy

every hour, and then have your favorite mailer (I don't do mail on my box, so I can't help you here) mail you the file ~/ip_addy every hour.

I used to make a lot of cron jobs, but I've forgotten how to. Fortuantely, the info and man pages on cron and crontab are pretty good.

[bruce1271e1271]

I had the same problem.

I wrote a few scripts to
1) Every night(3am) take down eth0 and then Bring it back up.
2) Compare the New IP to the previous IP and email me if there is a difference.
3)I also added the script to my boot-up files to run on every boot-up to compare to previous shutdown.

I used Perl to write the simple scripts..took ~1/2 Hour.

Do something like this and then you can be notified.

Good luck.

[z0mbix]

Create a script something along the lines of:


#!/bin/bash

IP=`/sbin/ifconfig eth0 | fgrep "inet ad" | cut -f2 -d":" | cut -f1 -d" "`

echo $IP > .currentIP
mail -s "New IP: $IP" foo@bar.com < .currentIP

Obviously change the eth0 to whichever interface is required.

Just add this to the script that is run everytime you connect. This differs from distro to distro.