Internet > How
the Internet works > Domain Name System >
Domain Name Aliases
IP addresses and
10 decimal digits are sometimes used in place of domain names,
usually in a web URL.
This is a bad, error-prone idea for anything but the most
transitory information, since the whole point of using a domain
name is that
it won't change
if the IP address does,
so these types of numeric URL's should not be used for long term. The two
types of domain name aliases are described below:
addresses. You sometimes see a web URL with the
IP address specified instead
of the domain name, as in the following:
You can convert a domain name to an IP address by pinging it,
as in "ping www.yahoo.com", and reading the response provided. In this
case, you can convert an alias IP address to a domain name by doing an NSLOOKUP,
the mapping is not one-to-one -- more
than one domain may point at the same IP address.
- 10 digits. You
sometimes see just a 10 digit number for a domain name, as in the following:
The number 3124567890 is just the decimal representation of an IP address,
usually represented by 32 binary bits divided into 4 sections and
for human consumption like 126.96.36.199.
The fastest way to find out the regular IP address of a domain specified
with a decimal number is to ping that decimal
number, which will then display the IP address in the ping response, whether
or not it reaches the site. Mathematically, you can also convert a decimal
IP to a regular IP with
- Hexadecimal. Convert the number into Hexadecimal
by hand, with a calculator, or with the dec2hex
function in Excel.
- Truncate. Take the right-most eight hex digits.
- Decimal. Convert the digits in sets of two into the four decimal
IP numbers, by converting each set of two hex digits into decimal by hand,
with a calculator, or with the hex2dec function in Excel.