ping - Difference between pinging with and without http://

I am trying to ping my website http://www.example.com/ and it resolves to an unknown IP address and times out.

PING http://www.example.com/ (198.105.254.228): 56 data bytes
Request timeout for icmp_seq 0
Request timeout for icmp_seq 1
Request timeout for icmp_seq 2

but when I ping example.com it works

What is it that I'm missing out here?

Answer

I am trying to ping my website http://www.example.com/ and it resolves to an unknown IP address and times out.

PING http://www.example.com/ (198.105.254.228): 56 data bytes
Request timeout for icmp_seq 0

The argument to ping is a hostname (or an IP address).

So the following will all work:

ping example.com
ping www.example.com
ping 127.0.0.1

On the other hand,

ping http://www.example.com/

will not work as http://www.example.com/ is an HTTP Uniform Resource Locator (URL) not a valid hostname (although part of it is a hostname).

A HTTP URL is made up of 4 parts:

• Scheme — always present


• Hostname — always present


• Path or Stem — always present but sometimes is null


• Parameters — optional

Ping will not normally recognise URLs as a valid destination hostname.

Notes:

• Not all URLs have the format mentioned above.




• A complete URL consists of a naming scheme specifier followed by a
  string whose format is a function of the naming scheme.




• The format of a URL is defined in the IETF specification Uniform Resource Locators (URL)

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DNS Hijacking

An exception to the above can happen if the DNS server (which resolves hostnames to IP addresses) is configured to return a valid IP address even if an invalid hostname is supplied.

This can happen if an ISP is hijacking your DNS queries.

From the answer Why is ping resolving to an IP 198.105.254.228 for any random hostname that i type? by Michael Hampton:

They are trying to be "helpful" by redirecting requests for
nonexistent domains to a white label service that provides search
results and advertising, from which everyone but you gets a cut of the
revenue.

Fortunately they do have a preferences page where you can
supposedly turn it off.