Logging in through Public IP for troubleshooting port forwarding...possible?

[klwilbur2]

Hello all,

I have a security system that I've opened up port 443 for and a camera/DVR system I've opened port 80 for.

When I'm within my home network, I can ping each of these and log into them fine (using their local IP addresses).  However, I am having some issues with logging in remotely and confirming the ports are open.

Question 1: is the public IP of my router static? 

Question 2: is there any way from within the home network to log in through the public IP address for troubleshooting purposes?  I need to do this to confirm my port forwarding is working correctly and I'll be able to connect remotely.  Otherwise, I'd need to leave my house and log in somewhere else for each troubleshooting step.  However, in the past this has failed (timed out) and I thought I read something on the forums that this might not be possible for some unknown reason.

Thanks for any help you all can provide.

Kelly

[SomeJoe7777 ACE - Geek]

Which modem/gateway do you have?

The 2Wire/Pace gateways will allow loopback connections to the external IP address if you're not using DMZ mode.

The Motorola modem/gateways will not.

[klwilbur2]

I have a 2Wire 3801HGV.

[SomeJoe7777 ACE - Geek]

If you have the ports opened properly, then you should be able to browse to the public IP address, and the 3801 will loopback the connection to the proper computer.

Example: If you have opened a firewall port for port 80 to the computer at 192.168.1.40, and your outside IP address is 99.99.99.99, then you should be able to browse to:

http://99.99.99.99

which would bring up the web server from 192.168.1.40.

[klwilbur2]

Thanks...just a few more quick questions...

When I get everything working and type in my public IP address, how does the request know which local device to access?

For instance, my DVR requires port 80 to be open.  I believe that configuration allows for it to be accessed remotely by simply typing in http://[public IP address] (because that protocol selects port 80?).  My security system requires port 443 to be open.  I believe that configuration allows for it to be accessed remotely by using httpS://[public IP address] (because that protocol selects port 443?)

My questions are:

1): are my assumptions about internet routing correct?

And more importantly...

2): what if I had two DVRs (with different local IP addresses) with port 80 open.  When I typed in http://[public IP address] how would the public IP address know which local IP to route the traffic to?  Would there be a conflict?

Thanks,

Kelly

[SomeJoe7777 ACE - Geek]

The 2Wire knows which local device to route the request to because you've opened that port and told it what local device to use when you created the firewall pinhole.

Because of that, 2 devices cannot use the same port. If you have two devices that both need to respond on port 80, that will not work. One of the devices will have to use a different port number, such as 81.

[klwilbur2]

SomeJoe7777...thanks for your responses.

There are some things that are not clear to me...I must be missing something.  Maybe if I try to break it down like this...

When you type in http://[MY PUBLIC IP] from an external server, where is that request routed?  Since you are adding nothing else to the address, how would it even know what port you are specifying?  So how would the router even know where to route such a request?

Same thing with https://[MY PUBLIC IP].

My assumptions were that anything starting with http would be automatically routed through port 80 and anything starting with httpS would automatically be routed through port 443.  However, I wanted to check and see if this was true.

If those assumptions are true, then I wanted to see if there was anything you could add on to the address to get it to route to a different port.

Thanks,

Kelly

[SomeJoe7777 ACE - Geek]

Yes, by default, any address that starts with http:// connects to the specified server (either directly by IP address e.g. http://192.168.1.254 , or by DNS lookup to an IP address, e.g. http://www.google.com ) on port 80. Port 80 is the default for http.

Similarly, https:// by default connects to port 443.

If you want to specifically connect to a different port, you do that by appending a colon and the port number to the end of the address, e.g. http://192.168.1.254:8080 will connect to the web server at 192.168.1.254 on port 8080. However, the server MUST be specifically configured to listen on that port. By default, servers do not listen on non-standard ports, you must configure them to do so.

So, if you have two web servers behind the RG for example, and you need to connect to both of them, you do this:

1. For web server #1, you leave it's settings at default (it will listen on port 80). You configure the RG with a firewall pinhole to route port 80 to web server #1.

2. For web server #2, you configure it to listen on a different port (say, port 81). Once that's done, you then go back to the RG and open a second firewall pinhole to route port 81 to web server #2.

Now, from outside, you can connect to both web servers using:

http://[public IP address]

(connects to web server #1)

http://[public IP address]:81

(connects to web server #2)