IP question

is it possible for an internet IP to be in the range 10.x.x.x, 90.x.x.x, 172.16-31.x.x ,192.168.x.x. which are reserved for intranet used?

thnks

No, I don't think so, as long as all of those are used for Internal use.

(If I still remember what I'd studied in MCSE)

First , there is ano Organization that handle this which called "The Internet Assigned Numbers Authority (IANA)"

Second ,IP addresses are classified into 5 classes . Class D is reserved for multicasting , Class E is reserved for future use .

Third ,127.0.0.1 : is reserved for pinging and testing functionality of your LAN Card .

I refered back to my resources and it says : These IPs are reserved for LANs :
10.0.0.0
172.16.0.0
192.168.0.0

You can use other IPs on the internet .

Hope this help you out !

yes i found that also but my real problem is the following i have a project a web site that i was been asked to put a password when viewed from the internet and no pass when viewed from intranet .so i m asking by checking the referer ip am i going to accomplish it or there is a better way of doing it

I think this way is the only and best way I can think of right now .

Not all LANs use the internal addresses. If it's an internet-connected network, and your organisation has an IP block, the individual computers will have proper, routable addresses.

Having "local" addresses requires the use of NAT (a horrible solution to the problem of too few IPv4 addresses) on the gateway.

If they're local addresses, this will work fine. Other than that, you'll have to find out your IP block, and verify addresses based on this.