Dynamic IP Script

eur0disciple · 01-10-2009, 05:03 PM

My ISP assigns me a dynamic IP address. I would like to be able to run a script on my Slackbox that sends an email when the public IP address changes. Can anyone point me in the right direction? Has/is anyone used/using a script that performs this task. Any help would be much appreciated.

bgeddy · 01-10-2009, 05:18 PM

You could use the services of no-ip.com or dyndns.com. They have scripts that updates their dns when your ip changes. I'm not sure how these work if you're behing a nat'ed router. Some routers have this functionality built in. If you are behind a router using Nat then it may be difficult, but not impossible, to sense when your public ip changes from the attached pc.

There are other scripts available - Google finds these although the same limitations would apply.

Chuck56 · 01-10-2009, 05:53 PM

I use a few free subdomains from dyndns.com and then use http://ddclient.wiki.sourceforge.net/ as the update program. SlackBuilds.org has a ddclient package builder which makes it easier.

larryhaja · 01-10-2009, 07:37 PM

I've used dyndns.com in the past. Most newer routers have the feature built in so that it takes care of any updated dhcp ip address. Using a client also works but I've never tried it. The only issue I've found with dyndns.com is that when using their free service you have to log in every now and then or else they close your account. I believe it is once every 28 days, which is reasonable for a free service.

amnesiavivace · 01-10-2009, 07:52 PM

Quote:

Originally Posted by eur0disciple

My ISP assigns me a dynamic IP address. I would like to be able to run a script on my Slackbox that sends an email when the public IP address changes. Can anyone point me in the right direction? Has/is anyone used/using a script that performs this task. Any help would be much appreciated.

I have a script that checks the status page of my Linksys router.
curl the status page, parse the IP line, check against a saved file containing the original IP. send email if its different. I also have the script update my zoneedit.com settings for dns.

Chuck56 · 01-10-2009, 09:32 PM

Quote:

Originally Posted by larryhaja

The only issue I've found with dyndns.com is that when using their free service you have to log in every now and then or else they close your account. I believe it is once every 28 days, which is reasonable for a free service.

You set ddclient to force updates every 28 days even if your IP doesn't change which keeps your account current.

mRgOBLIN · 01-10-2009, 10:30 PM

Yep ddclient is the way to go.. been using it for years.

eur0disciple · 01-11-2009, 02:47 PM

Thanks for the replies. Does anyone know a good resource to read up on bash scripting?

I think this will be beneficial in the future.

TSquaredF · 01-11-2009, 02:55 PM

Quote:

Originally Posted by eur0disciple

Thanks for the replies. Does anyone know a good resource to read up on bash scripting?

I think this will be beneficial in the future.

Advanced BASH Scripting Guide

mangec · 09-01-2009, 08:22 AM

Hello,

Did somebody experience connection problem to dynamic.zoneedit.com since less than 2 weeks. Before starting to involve DDCLIENT, I would like to know if I am the only victim since ZONEEDIT already had problems one year ago.

Symptom is :
Aug 29 03:00:27 orinoco ddclient[1394]: FAILED: updating blog.xxxxx.net,xxxxx.net,emg.xxxxx.net,telem.xxxxx.net: Could not connect to dynamic.zoneedit.com.

thanks to all

tux_dude · 09-01-2009, 08:55 AM

Here is a simple little script is used to to check when my ip changes and restart my ftp server.
Bad, bad coding...added comments.

Code:

#!/bin/sh
FILEPATH='/var/run/proftpd'
IPfile='masq_ip'

# Check if ip file exits. Create it if its not present.
if [ ! -r ${FILEPATH}/${IPfile} ]; then
        touch ${FILEPATH}/${IPfile}
fi

# Check if noip is running. NOIP is used for my dynamic dns. Start it if its not.
if [ ! "`ps -ef | grep noip2 | grep -v grep`" ]; then
        /usr/local/bin/noip2 2>&1>/dev/null
        sleep 15
fi

# Get old IP from IP file
oldip=`cat ${FILEPATH}/${IPfile}`

# Get current IP from noip
newip=`/usr/local/bin/noip2 -S 2>&1 | grep "IP Address" | awk {'print $5'}`

# Restart proftpd and update ip file if the IP has changed.
if [  "$oldip" != "$newip" ]; then
        /etc/rc.d/rc.proftpd restart 2>&1>/dev/null
        echo $newip > ${FILEPATH}/${IPfile}
fi