multiple ip for one vps

[mahesh]

I'm new to Linux and ubuntu
I have one vps with two public ip address (both are valid) for example IP1 and IP2, but when I ping them from another pc, only one of theme response to my ping, other one I got time out, can any one help me to fix this?
I setup http server on my vps,
http server response only to IP1, is there anyway to server response to both IP1 and IP2?
regards