dynamic-dns version 1.0

these scripts resolve a domain name to a changing ip address without the need to pay for a similar service. you will need a web-accessible website with a domain name or fixed ip to store the server's ip address and act as intermediary.

an example use-case might be to access ssh on your home-pc while at work. if your isp has allocated a static ip to your home network then you will not need this project - you could simply go ssh [email protected]. however if your isp allocates a dynamic ip address then this will not work once the ip address changes, and you will need to use this project or else some other service like dyndns.org (which is no longer free) to do the job for you.

in this project:

• "server" refers to the machine being accessed (eg the webserver or ssh server that you want to connect to)
• "client" refers to the machine which is connecting
• "intermediary" refers to the machine which stores the server ip address and relays it to the client upon request

this project was developed for debian/ubuntu but can be made to run on any flavor of linux.

server setup

 # first install all dependencies:
 sudo apt-get install git-core wget php5 ntp

 # then checkout the files into a common directory owned by root:
 cd /usr/share/
 sudo git clone git://github.com/mulllhausen/dynamic-dns.git \
 mulll-dynamic-dns

 # edit the wget url host in the server.sh script - change
 # intermediary.com to the hostname of your intermediary server.

 # also change the password in the server.sh script to something long and
 # unguessable.

 # ensure the server time is correct:
 date

 # finally, add a line to /etc/crontab to run the server.sh script every
 # minute:
 * * * * * root /usr/share/mulll-dynamic-dns/server.sh

intermediary setup

 # first install all dependencies:
 sudo apt-get install git-core php5 ntp

 # then checkout the files into a common directory owned by root:
 cd /usr/share/
 sudo git clone git://github.com/mulllhausen/dynamic-dns.git \
 mulll-dynamic-dns
 cd mulll-dynamic-dns/

 # remove all files except for intermediary_ip.php:
 sudo rm LICENSE README.md server.sh client.sh

 # edit the password in the intermediary_ip.php file to be the same as the
 # password you chose for server.sh above.

 # set up your favourite webserver with php to run the intermediary_ip.php
 # upon request, eg for apache:
 sudo apt-get install apache2 libapache2-mod-php5

 # now add the following text to /etc/apache2/sites-enabled/000-default
 # between the <virtualhost></virtualhost> tags. use the *:443 virtualhost
 # to avoid man-in-the-middle attacks:

 alias /mulll-dynamic-dns/ "/usr/share/mulll-dynamic-dns/"
 <directory "/usr/share/mulll-dynamic-dns/">
   allow from all
 </directory>

 # finally, ensure the server time is correct:
 date

client setup

warning - the client.sh script will be altering your /etc/hosts file. if the script contains bugs then it may mangle or potentially wipe out this file.

 # before anything else, backup your /etc/hosts file:
 sudo cp /etc/hosts /etc/hosts.backup0001

 # now install all dependencies:
 sudo apt-get install git-core wget php5 ntp

 # then checkout the files into a common directory owned by root:
 cd /usr/share/
 sudo git clone git://github.com/mulllhausen/dynamic-dns.git \
 mulll-dynamic-dns

 # edit the wget url host in the client.sh script - change
 # intermediary.com to the hostname of your intermediary server.

 # change the password in the client.sh script to something long and
 # unguessable.

 # change the server_hostname variable in the client.sh script to be the
 # name of the server

 # ensure the server time is correct:
 date

 # finally, add a line to /etc/crontab to run the client.sh script every
 # minute:
 * * * * * root /usr/share/mulll-dynamic-dns/client.sh

bugs

no known bugs so far :)

author

petermiller1986 [at] gmail.com

copyright (C) 2007 free software foundation, inc. (see LICENSE file in this project for details)