How is the "Private IP address" field supposed to work?

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How is the "Private IP address" field supposed to work?

I have been trying to forward port 25565 using an Airport Extreme. I know how to forward ports, and I know my IPv4 address is 10.0.1.2. The router (Airport Extreme)'s address is 10.0.1.1. However, when I go into the AirPort Utility and try to configure this, it gives me a field after "10.0.1.2" asking for some mysterious extra number on the end of this already complete address. It will not let me continue without filling this box out, but what do I put in it? ipconfig clearly shows that 10.0.1.2 is the extent of my computer's private IP. What do I put in this box? How is this supposed to work at all?

Also, the "Browse..." button to the right of the mysterious field is utterly useless; it opens a window showing nothing in particular.

AirPort Extreme-OTHER, Windows 7

Posted on Sep 15, 2011 10:26 PM

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Answer 1

Tesserax

Level 10

148,327 points

Sep 16, 2011 12:04 AM in response to noremakk

Configuring port mapping on the Extreme typically takes two basic steps. Configuring the host with either a static or DHCP-reserved IP address, and then, assigning the appropriate UDP & TCP ports to the host.

AEBSn - Port Mapping Setup

To setup port mapping on an 802.11n AirPort Extreme Base Station (AEBSn), either connect to the AEBSn's wireless network or temporarily connect directly, using an Ethernet cable, to one of the LAN port of the AEBSn, and then use the AirPort Utility, in Manual Setup, to make these settings:

1. Reserve a DHCP-provided IP address for the host device.

AirPort Utility > Select the AEBSn > Manual Setup > Internet > DHCP tab

On the DHCP tab, click the "+" (Add) button to enter DHCP Reservations.
Description: <enter the desired description of the host device>
Reserve address by: MAC Address
Click Continue.
MAC Address: <enter the MAC (what Apple calls Ethernet ID if you are using wired or AirPort ID if wireless) hardware address of the host computer>
IPv4 Address: <enter the desired IP address>
Click Done.

2. Setup Port Mapping on the AEBSn.

AirPort Utility > Select the AEBSn > Manual Setup >Advanced > Port Mapping tab

Click the "+" (Add) button
Service: <choose the appropriate service from the Service pop-up menu>
Public UDP Port(s): <enter the appropriate UDP port values>
Public TCP Port(s): <enter the appropriate TCP port values>
Private IP Address: <enter the IP address of the host server>
Private UDP Port(s): <enter the same as Public UDP Ports or your choice>
Private TCP Port(s): <enter the same as Public TCP Ports or your choice>
Click "Continue"

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Answer 2

noremakk Author

Level 1

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Sep 16, 2011 1:56 PM in response to Tesserax

Unfortunately, my AirPort Utility looks nothing like you've described. Here is what my DHCP tab looks like:

This is what the window under Port Mapping I was describing looks like (complete with the mystery field):

And here's my ipconfig -all output, just for information:

How do I find what AirPort Utility claims is my "Private IP Address"? My computer seems to claim it is just 10.0.1.2, while the program seems to want something along the lines of 10.0.1.2x.

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Answer 3

Tesserax

Level 10

148,327 points

Sep 16, 2011 2:51 PM in response to noremakk

Hmm, I pulled up some AirPort Utility screenshots of when I had a 802.11g AirPort Extreme Base Station (AEBS), and my Port Mapping window was different as you will see below.

... so I'm not sure which exact version of the AirPort Utility you are using. Regardless, in your case, 10.0.1.2 would be the correct Private IP Address. Were you not able to create the mapping without entering a value in the window to the right of the Private IP Address field?

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Answer 4

noremakk Author

Level 1

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Sep 16, 2011 4:02 PM in response to Tesserax

I'm using AirPort Utility version 5.5.3 on a Windows 7 machine. I was not able to create the mapping without entering a value: when I leave it blank, I get an error saying "Some fields were left blank or contain invalid values. Make sure all fields are filled in with valid values and try again." I also get this error if I try putting a 0 in the field.

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