[ale] Comcast DHCP

[Scott McDonald]

>Atlanta Linux Enthusiasts wrote:
>> So I
>> wrote a script that runs every few minutes, it checks ifconfig output,
>> hacks it up with grep and awk, writes it to a tmp file, compares with
>> the old tmp file, and IF my ip has change it then uses lynx to call a
>> zoneedit.com url to update my zones with my new IP.
>
>I'm sure that was fun, but why not use http://ddclient.sourceforge.net/
>, http://zoneclient.sourceforge.net/ , or http://inadyn.ina-tech.net/?
>
>-Brian

Well... ddclient and zoneclient I had not heard of before...

I had heard of ez-ipupdate, so I started there.  Looking for docs to
set it up I saw a lot of hits from people saying not to use it, to use
inadyn.   So I tried apt-get install inadyn and there it was.   Then I
started looking for docs on getting inadyn to work with zoneedit, and
didn't get very far... so I dropped back to man inadyn, and there was
a ton of stuff to read, and I'm lazy... so instead I had 10 mins of
fun throwing this together, which works great for me.

Thanks,
-Scott

-----
#!/bin/sh
#
# JSM: dydns.sh - quick zoneedit.com update for dynamic ip when it changes
# JSM: drop this script in /root/dydns/ directory and run it from cron
every 5 mins
# JSM: change the UsErNaMe:PaSsWoRd and host in the update urls
#
GATEWAYIPADDRESS="/root/dydns/ipaddress"
GATEWAYIPADDRESSOLD="/root/dydns/ipaddress.old"

/sbin/ifconfig | /usr/bin/head | /bin/grep "inet addr" | /usr/bin/awk
'{print $2}' | /usr/bin/awk -F: '{print $2}' > $GATEWAYIPADDRESS
if [ $? -ne 0 ]
then
  echo "Cannot ifconfig beyotch"
  exit
fi

# make sure successful
if [ -f $GATEWAYIPADDRESS ]
then

# assume at first that IP address has not changed
IPCHANGED="no"

# check if there is an old address to compare to
if [ -f $GATEWAYIPADDRESSOLD ]
then

  # checks to see if they are different
  diff $GATEWAYIPADDRESS $GATEWAYIPADDRESSOLD | grep "." > /dev/null
  if [ $? -eq 0 ]
  then
    # OK, we know they are different
    # set the change variable appropriately
    IPCHANGED="yes"
    rm $GATEWAYIPADDRESSOLD
    mv $GATEWAYIPADDRESS $GATEWAYIPADDRESSOLD
  fi
else

  # else just create the old $GATEWAYIPADDRESSOLD file
  mv $GATEWAYIPADDRESS $GATEWAYIPADDRESSOLD
  # set the change variable appropriately
  IPCHANGED="yes"
fi

# Now send the message if the ip address has indeed been changed
if [ $IPCHANGED = "yes" ]
then
lynx -source -auth=UsErNaMe:PaSsWoRd
http://dynamic.zoneedit.com/auth/dynamic.html?host=twopeanuts.com
    # what to do in case of failure
    if [ $? -ne 0 ]
    then
      echo "Error browsing to Zoneedit"
      rm $GATEWAYIPADDRESSOLD
      exit
    fi
lynx -source -auth=UsErNaMe:PaSsWoRd
http://dynamic.zoneedit.com/auth/dynamic.html?host=dancestuffetc.com
    # what to do in case of failure
    if [ $? -ne 0 ]
    then
      echo "Error browsing to Zoneedit"
      rm $GATEWAYIPADDRESSOLD
      exit
    fi
fi

# Problems reading/writing to the file
else
  echo "Cannot access $GATEWAYIPADDRESS"
fi