Page 124 - DCAP602_NETWORK_OPERATING_SYSTEMS_I

Network Operating Systems-I

notes

Task Analyse the use of domain without servers.

Domain-less Dns

If you have a broadband Internet connection with no static IP and have no desire to have your
own domain name, you can use a free service offered by dyndns.org to set up a home Web/e-
mail/ftp server. It offers a dynamic DNS service which will redirect traffic to your server using
their domain name.

With this free service you use your server’s hostname but dyndns.org’s domain name. You’re
mainly just adding/modifying an A record for your server in their zone file. Your Web server
would have a URL like:
http://your-hostname.dyndns.org
E-mail addressed to your server would have to have an address like:

you@your-hostname.dyndns.org
As you’ll be using your hostname with dyndns.org’s domain name, you have to confirm your
hostname isn’t the same as that of anyone else using their service. As a result, you’ll want to come
up with a hostname for your server that’s really unique. Recall that you set the hostname during
the installation. You can always change it by editing the /etc/hosts file. However, you’ll also
need to check for the current hostname in the configuration files of any server applications that
may use it, such as Sendmail and Apache, and edit those files as well.
If you connect your Linux server to the Internet using a modem (we show you how on the
Modems page), you’ll want a way to keep your connection up long enough for any dynamic
DNS changes to take effect and this could take up to 45 minutes. Most ISPs will drop an inactive
connection before that. You can use the ping command to keep your PPP connection up. The
trick is to run it in the background and set it so it only sends a ping once every five minutes. Pick
a Web site and enter:

ping -i 300 www.chosen-site.com > /dev/null &
Just don’t forget to bring it to the foreground and stop it once you’ve disconnected your modem
connection. To bring it to the foreground simply type:

fg ping
and then press Ctrl-C to exit the ping program.
ddclient Configuration File for dyndns.org
If you selected the dyndns.org service when you installed ddclient your /etc/ddclient.conf file
should look something like this:

# Configuration file for ddclient generated by debconf
#
# /etc/ddclient.conf
pid=/var/run/ddclient.pid
protocol=dyndns2
use=if, if=ppp0
server=members.dyndns.org

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