javascript - Difference between localhost and IP address in Ajax request sending -

i have strange problem native ajax request invoking.

i creating ajax object , sending request follows:

var xmlhttpobj = new xmlhttprequest(); 

....

xmlhttpobj.open("get","http://192.168.16.254:8080/ajax/demoexample.html",true); xmlhttpobj.send(); 

when access servlet url http://localhost:8080/ajax..., not able response in client side. can see response in server side.

pretty similar way invoked request

xmlhttpobj.open("get","http://localhost:8080/ajax/demoexample.html",true); 

and url http://192.168.16.254:8080/ajax..., not able see response in client side.

i know best way fix problem.

i can invoke request

xmlhttpobj.open("get","../ajax/demoexample.html",true); xmlhttpobj.send(); 

then don't have problem either localhost or ip address.

but still think why difference between localhost , ip address in ajax requesting.

it's more of security feature problem :

the same origin policy prevents document or script loaded 1 origin getting or setting properties of document origin.

localhost , 192.168.16.254 considered different origins. same goes 2 hostnames point same address (and will) point different site/application on same server. afaik way around use iframe content or jsonp json. although in case relative urls way go.