Is it possible that one domain name has multiple corresponding IP addresses?

Question

For example, when we connect to www.example.com, at first we try to connect to 192.0.2.1. And if first try fails, then we try 192.0.2.222

Answer 1

You can do it. That is what big guys do as well.

First query:

» host google.com 
google.com has address 74.125.232.230
google.com has address 74.125.232.231
google.com has address 74.125.232.232
google.com has address 74.125.232.233
google.com has address 74.125.232.238
google.com has address 74.125.232.224
google.com has address 74.125.232.225
google.com has address 74.125.232.226
google.com has address 74.125.232.227
google.com has address 74.125.232.228
google.com has address 74.125.232.229

Next query:

» host google.com
google.com has address 74.125.232.224
google.com has address 74.125.232.225
google.com has address 74.125.232.226
google.com has address 74.125.232.227
google.com has address 74.125.232.228
google.com has address 74.125.232.229
google.com has address 74.125.232.230
google.com has address 74.125.232.231
google.com has address 74.125.232.232
google.com has address 74.125.232.233
google.com has address 74.125.232.238

As you see, the list of IPs rotated around, but the relative order between two IPs stayed the same.

Update: I see several comments bragging about how DNS round-robin is not convenient for fail-over, so here is the summary: DNS is not for fail-over. So it is obviously not good for fail-over. It was never designed to be a solution for fail-over.