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Port forwarding in network configuration problem

Posts: 51
Registered: 30-07-2007

Port forwarding in network configuration problem

I have a network configuration problem.
I want to allow port forwarding. This is the setup.

Modem - Actiontec DSL USB/Ethernet modem (default IP address - can also be used as a router) connected to

Wireless Router - Dell Truemobile 1184 (default IP address

Both have DHCP facilty and both can allow port forwarding.
The problem is the modem will only allow port forwarding on the same subnet (192.168.0.x).
If I assign to the router, nothing works.

So which device do I allow to control DHCP and what addresses should I assign where?
Can I forget NAT - or should this be disabled on one of the devices - if so which one?
I have two PCs wirelessly connected. This works OK if the I allow the Dell router to control DHCP but cannot then get port forwarding.



Port forwarding in network configuration problem

One of you problems is you are using a wireless router in NAT mode. There is no real need for this, however, you can get around it.

Lets define what a router is.

A router is a devices that acts as either a gateway or traffic managment system. It consists of 2 or more interfaces. It takes traffic from one interface, and will route it over another interface based on rules. On an device with more than 2 interfaces, it can route based on traffic load or even the destination of the traffic.

An interface is defiend as each seperate socket on the device. In a DSL router, there are 2 interfaces, 1 the LAN, and 2 to the ADSL socket.

Each interface is assigned its very own IP address.

The ADSL port of the main USB/Ethernet router has the static IP assigned by PlusNet(A), and the LAN side has

The same applies to your wireless router. On its LAN side it has a IP address of The WAN side (where the wire goes to the main router) also has an IP address. This will be one assigned by either DHCP or manualy in the config (D).

Now to configure the port forwards.

As you may note above, I have set each interface with a letter (A, B, C, D). This is so you know what IP address we talk of.

1: In the config of the A+B router, you need to setup your original port forward, to the IP address assigned to interface D.

2: In the config of the C+D router, you need to make a port forward to the machine on the wireless LAN.

The confusion arrises due to having 2 routers when you only need the original ADSL USB/ethoernet router & a Wireless access point.

You WAP is a WAP+Router combined.

This sinply involves a two step port forwarding system isntead.

Port forwarding in network configuration problem

To add to what "acarr" has said, you may find the exchanges in the Wireless Router topic are helpful.
Posts: 51
Registered: 30-07-2007

Port forwarding in network configuration problem

Wow, what a job. Three days but I got there eventually!! Cheesy

This is how I got the port forwarding working through the two devices.

I enabled DHCP on both the modem/router and the WAP/router.

The modem had IP 192.168.01 and this assigned to the WAN side of the WAP/router. (What happened to I do not know).

Port forwarding was enabled to

The WAP/router ( then passed address to the first PC.
In this device, port forward was set to

So, the PC was able to "see" the forwarded ports :-)

I think I tried all other possible combinations but this was the only one that worked for me.
Thanks to all for your help.