How to host your own domain from a broadband connection

Dynamic IP and ZoneEdit.com
First things first: I am assuming that you have a DSL or Cable Modem connection. If you are

like 95% of the broadband world then your home network IP address is assigned dynamically,

meaning that it changes periodically. This is not a problem if you just want to "get on" the

internet, but this is a huge problem if you actually want to HOST your own domain (like

spencerstirling.com) on a server in your house. Many people will probably opt to just pay

somebody else to host their site - that's fine, but not nearly as fun.

Here's the problem with a dynamic PUBLIC IP address: when somebody types

www.spencerstirling.com, the DNS name resolver doesn't know where to go (because the actual

address keeps changing). This is where so-called "dynamic DNS" comes in handy. I use a free

service available from www.zoneedit.com. Here's how it works: you can buy a domain name from

several "official" domain registries, like "www.000domains.com" or "www.godaddy.com". These

companies just provide the NAME, not a place to actually PUT your website. This is the job

of your domain "host". If you are reading this document then I assume that you want the host

to be - YOU (a server on your home network)!

The domain registry usually only provides the barebones of services. For example, maybe you

already have a hosted website, but it has a terrible name like:

www.yahoo.com/users/imanidiot/complicatedurl/nobodywillrememberthis/blahblah.html

then your domain registry will often provide a service called URL forwarding. This just

means that somebody can type in your easy new domain name (like www.spencerstirling.com) and

they will be automatically forwarded to the terribly-named site above. For this to work you

will already have to have your website hosted somewhere, you just don't like the name (so

you're going to choose an easier name to point to it).

Another possibility is that your home network might have a static IP, in which case you can

just set up your website on your home server and tell your domain registry to point

www.spencerstirling.com to the address of your home server. That's REALLY easy.

Unfortunately, most people don't want to pay the extra $$$ that it takes for a static IP

(usually requires an upgrade of your DSL to a small business account).

In comes Zoneedit! You can configure your official domain registry to use the DNS servers

provided by Zoneedit (a third party company). That means that whenever anybody asks where to

find www.spencerstirling.com, your official registry will say "I don't know" and ask the

servers over at Zoneedit. The beauty is that the servers over at Zoneedit can be updated

with the latest information rather often - meaning that you can update your latest IP

address whenever it changes. This is called "Dynamic DNS". In fact, *some* official domain

registries also provide this service (but mine doesn't), so you may be able to avoid

Zoneedit altogether!

The instructions available on www.zoneedit.com for "dynamic DNS" are pretty much self-

explanatory. You will need to obtain an account with them. There they will assign you a

couple of nameservers to use. In my case they told me to use

ns3.zoneedit.com
ns17.zoneedit.com

Hence I logged on to my domain registry (www.godaddy.com) and told it to use the DNS servers

over at ZoneEdit (instead of using Godaddy's nameservers) whenever anybody asks where to

find www.spencerstirling.com.

The ONLY issue left is that you need to know how to update the ZoneEdit nameservers with

your latest IP address periodically. On their "dynamic DNS" howto they have a method using

"lynx" - this is the one that I'm using. So I wrote the following script and put it in

"/root/update_zoneedit/update_zoneedit" UPDATE April 2006: modified script slightly for

better error checking (still sucks)


#!/bin/sh
# Make sure that you have "lynx" INSTALLED!!!
# This script tries to update your Zoneedit profile whenever
# your IP address changes

GATEWAYIPADDRESS="${HOME}/report_gateway_ip_zoneedit/ipaddress"
GATEWAYIPADDRESSOLD="${HOME}/report_gateway_ip_zoneedit/ipaddress.old"
TEMP="${HOME}/report_gateway_ip_zoneedit/temp"
GATEWAYPAGE="http://www.whatismyip.com"
KEYPHRASE="Your IP"
USERNAME="zoneeditusername"
PASSWORD="password"
MYDOMAIN1="foo.com"
MYDOMAIN2="foo2.com"
MYDOMAIN3="foo3.com"

# get the ip address of the gateway
lynx -dump $GATEWAYPAGE &> $TEMP
if [ $? -ne 0 ]
then
echo "Cannot browse to $GATEWAYPAGE"
exit
fi
cat $TEMP | grep "$KEYPHRASE" > $GATEWAYIPADDRESS

# make sure the browse was 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 $GATEWAYIPADDRESSOLD | grep "$KEYPHRASE" > /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=${MYDOMAIN1} 2> /dev/null
# 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=${MYDOMAIN2} 2> /dev/null
# 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=${MYDOMAIN3} 2> /dev/null
# 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

I put this in my "crontab" file to be run every hour. A few comments are in order here. This

script checks the IP address hourly, but it only updates with ZoneEdit.com if the address

has CHANGED!!! This is the least we can do to preserve a free service. My only other comment

concerns the use of "http://www.whatismyip.com" hourly. This can be considered net abuse.

Although this will work, we don't want to make unnecessary demands on free services. In fact

I browse to a page on my router that gives the IP address. This keeps the traffic down.