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Explanation :

  1. I'm using windows xp sp3
  2. I've public IP (ex. 182.222.333.222)
  3. My ADSL-router IP :, and my static IP
  4. I've enabled NAT setting through my ADSL modem
  5. I've installed wamp server on my computer.

Case :

  1. My friend can accessing my public IP http://182.222.333.222
  2. I'm also can accessing my static ip or

But I can't access my public IP ? whats wrong with my network configuration?

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What you are trying to do here is called hairpinning, and is usually not supported on domestic ADSL routers, and is probably seen as IP Spoofing, as the source and the destination of the packet as it comes "in" to the router would both be 182.222.333.222 . Your source address would be NATted behind the public address of the router, and the destination is the same address.

The firewall sees an incoming packet apparently from its own address and drops it.

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how to avoid hairpinning? any solutions?. My friend using same ADSL modem, and same ISP, but he can access public IP through his LAN. – oknoorap Sep 27 '11 at 7:12
What is the router - has he disabled the firewall perhaps? – Paul Sep 27 '11 at 10:01

Many routers don't do 'loopback' like this. You're trying to essentially 'exit' your LAN, then re-enter it from outside. Works with some routers, not with others.

And @Paul answered it better, I wasn't aware there was a better term for it, but it works.

Be thankful your friend can see your machine, remember that you probably have a dynamic IP address and it'll change at some point, so you'll really want to set up some sort of DNS resolution. (free account @ works nicely, there are others).

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okay I'll try using dyndns, thanks. – oknoorap Sep 27 '11 at 7:14
using dyndns won't help resolve your present issue of not being able to connect to your public IP. But it'll help OTHER people to be able to always find your machine. You'll have an address like '' or something, rather than a string of numbers which will likely change at some point. Dyndns will not help resolve your question posted here. It's just a convenience for you. – lornix Sep 27 '11 at 7:22

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