Why "gmail.com" and "www.gmail.com" IPs navigate me to "google.com" homepage?

Question

As you see below I get a ping of www.gmail.com and gmail.com :

C:\>ping www.gmail.com

Pinging googlemail.l.google.com [74.125.232.149] with 32 bytes of data:
Reply from 74.125.232.149: bytes=32 time=118ms TTL=49
Reply from 74.125.232.149: bytes=32 time=119ms TTL=49
Reply from 74.125.232.149: bytes=32 time=118ms TTL=49
Reply from 74.125.232.149: bytes=32 time=124ms TTL=49

Ping statistics for 74.125.232.149:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 118ms, Maximum = 124ms, Average = 119ms

C:\>ping gmail.com

Pinging gmail.com [173.194.39.213] with 32 bytes of data:
Reply from 173.194.39.213: bytes=32 time=93ms TTL=51
Reply from 173.194.39.213: bytes=32 time=92ms TTL=51
Reply from 173.194.39.213: bytes=32 time=92ms TTL=51
Reply from 173.194.39.213: bytes=32 time=92ms TTL=51

Ping statistics for 173.194.39.213:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 92ms, Maximum = 93ms, Average = 92ms

C:\>

Q1: Why I received two different IP? (I think www.gmail.com is the same gmail.com, Isn't it?)

Q2: Why When I use these IPs to open Gmail homepage, I navigated to google homepage? (Try them)

Q3: What is gmail IP? can I open gmail homepage using an IP?

Answer 1

The relationship between a fqdn (a web address) and an IP address can be many to many.

In that many different IP addresses can serve the same websites, and a single IP address can serve many different websites.

When a webserver at an IP address is hosting multiple websites, it uses headers in the request sent from your browser to know which site to send back.

In the absence of a header saying which website is requested, there is often a default one. In Google's case, if a specific site is not requested from a server, it returns the Google search website.

Google has infrastructure world wide, with thousands of servers hosting google.com, gmail.com all its other web assets. This infrastructure changes on a daily basis depending on demand.

If for some reason you cannot use DNS to request gmail.com, your option is to edit your hosts file and add an entry for gmail (http://en.wikipedia.org/wiki/Hosts_%28file%29)

Edit c:\windows\system32\drivers\etc\hosts

Add

173.194.39.213 gmail.com

You may need to add others in case GMail brings in content from other domain names.

Then you can access gmail.com on

https://gmail.com