Lets say I have a router that is connected to the Internet. An WAN IP address is given by ISP. It is using PPPoE ADSL, the IP address is not static, every time it connected, assigned a different IP address.

There is an web server running in the LAN.

I heard something like DMZ + DynDNS can do the job? But not sure what these are and how they work.

Any there way(s) to access the local node via WAN, so that I can reach that node even I am not home.


By default, most routers will block traffic from outside the local network. If you want to have access to something on the LAN side of the router, you have to configure the router to allow that traffic to pass through.

One way is to open up specific ports (like, say, 80, if you are hosting a website). Traffic hitting the router on port 80 would then be allowed into the LAN. The second part of the port-forwarding configuration is to tell it which computer that port 80 traffic should go to. If you were hosting a website on, you'd forward 80 to that address.

Another way is to use a DMZ. This is functionally equivalent to opening up ALL the ports on the router, and sending all that traffic out a LAN port. It has its uses, but this is probably not ideal for you.

DynDNS, as Alen mentioned, is an online service that will pay attention to what your public facing IP address is, even as it changes. Instead of needing to know that IP, and entering that into a browser or terminal, or whatever, you enter a domain name (like myhouse.dyndns.com, or something like that) that is always pointing at your public IP.

In your case, I would set up a free DynDNS account, and configure port-forwarding on your router.

  • I've done this - it works well. – Mike Christiansen Sep 27 '12 at 7:59
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    Also note, some Cable/DSL routers will allow you to input your dyndns details, and it will automatically update. The normal way to do the updates is to run a service on your computer. – Mike Christiansen Sep 27 '12 at 8:00
  • Hey, I'm having the exact opposite problem. I can't access my server via the WAN IP address from my LAN. I've come across a lot of similar posts online, but none of their answers have been sufficient. I've heard lots about NAT. NAT looping, NAT reflection, etc. Not sure what to do exactly? Any help would greatly appreciated. – oldboy Aug 19 '17 at 7:49

You can use remote control software like TeamViewer. Software like this you just install and run without much configuration. You can login to you computer then from any computer either by using the Teamviewer on the other computer or by going to https://login.teamviewer.com/ in your browser and work on your computer from there.

There are other remote control applications, but TeamViewer is most widely use. It is free for personal use.

You can use VPN, either directly on you router (ISP suplied routers for ADSL usually don't have this), or on computer inside your LAN which you then map to the public IP. If you wan't to go with the VPN you can use OpenVPN, but like I said, you then need to map that computer on your ADSL router.

You can also map your computer to the public IP and connect using remote desktop.

If you just want to access the webpages that are on the web server, and you don't need to access the machine itself (login into the OS). then just map the machine on the router on port 80 and use DynDNS to access it.

DynDNS works that you install the client on your computer, which then updates you dyndns record with your current address when it changes

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