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Seperate Netgear ADSL Modem and Router Port Fordwarding..???


Seperate Netgear ADSL Modem and Router Port Fordwarding..???

hopefully someone can help me, its been driving me nuts for weeks now.
I have a Netgear DM602 ADSL Modem and Netgear RP614 router.
The problem is trying to get the relevant ports to forward to my local IP address, specifically

I think I've tried every configuration possible, DMZ on the modem set to local IP aswell as the routers DMZ, modem in modem and router mode, tried different subnet masks on the internal network....any help really appreciated.
It used to run fine when I was with NTL, cable modem straight into the router and it would forward ports no probs. What am I doing wrong with ADSL.?

many thanks


Seperate Netgear ADSL Modem and Router Port Fordwarding..???

Both your DM602 and RP614 do NAT processing. This is not a problem, as such, but you need to be aware of it in order to configure your network correctly.

There are a couple of recent topics which have dealt with similar network configurations to your own, and I suggest you read through these, and if you find you're still stuck, post back here for more help, but hopefully they will get you on your way.

I think both the other posts dealt with wireless devices, but don't be put off by that -- your RP614 is doing exactly the same thing as the wireless router in those topics.

Port Forwarding in Network Configuration problem
Wireless Router

Seperate Netgear ADSL Modem and Router Port Fordwarding..???

thanks taskforce9, i'd read those and got even more confused.
my main problem seems to be understanding how the modem translates the external IP into the private IP. so if the modem is, how can the routers IP also be which it is in my case.
the DHCP settings for the internal network start by default, shouldnt be the router address?

also, in order for me to access the internal config for the modem I must disconnect the router and plug straight into the modem. even re-configuring the router to be set to still wont allow me to access the modem at

should the router be on a different subnet?
i've also tried just using the modem in modem mode and logging into with the router software, but that wont work?

I used to think that I was pretty good at all this until I started getting into the depths of subnet masks and things.....

any more help appreciated.


Seperate Netgear ADSL Modem and Router Port Fordwarding..???

Ok, you've got two devices, the DM602 and RP614, which each have two IP addresses, a "WAN" address and a "LAN" address. The "WAN" address of the DM602 is your public IP address, and is the only one which is visible to the Internet as a whole.

The "LAN" interface of the DM602 is attached to the "WAN" interface of the RP614. This creates one network, and the addresses you use for the interfaces in this network must indicate that they are in the same network. So, if you use for the LAN interface of your DM602, you must use a 192.168.0 address -- say, -- for the "WAN" interface of your RP614. The subnet mask for both of these interfaces will be (which actually imples no subnetting, but we won't go into that), and for the "WAN" interface on the RP614, the default gateway, or default route (whatever they call it) must be (ie the LAN address of the DM602).

Turning now to the LAN side of the RP614, you have one or more cables connecting the RP614 to your PCs. The LAN interface of the RP614 and the other PCs are in a second network, and their addresses must indicate both that they are not in the same network as the first network and that they are in the same network as each other. So you cannot use 192.168.0 addresses for any of these network devices.

You could use 192.168.1 addresses, though, since this is a different network. So you could assign as the address on the "LAN" interface of the RP614 and addresses and upwards to each of your PCs connected to the RP614. Again, all of these should have a subnet mask of, and the PCs should have a default route ("default gateway" or whatever it's called) of (ie the LAN address of the RP614).

With this arrangement, from the PCs connected to the RP614, you should be able to access the webpages of the RP614 by specifying address You should also be able to access the DM602's web pages by specifying

If you add DNS addresses of and to the configuration of each of your PCs, you should then be able to access the Internet by using hostnames.

So that's taken care of connections initiated by you.

You now want to configure your DM602 and RP614 to allow incoming connection requests.

The only device on your network the DM602 is aware of (other than itself) is the RP614, which it knows as So port forwarding on the DM602 involves configuring it to forward to This will get the incoming connection request to your RP614 router.

You now need to configure your RP614 router to forward the request to the local PC you want it to end up on. This is exactly as you used to do it in your ntl days. (But the PC will now have a 192.168.1 address, according to the outline I've given).

Seperate Netgear ADSL Modem and Router Port Fordwarding..???

i cant thankyou enough for the clear and concise instructions, it now works a treat.
after changing the IP on the router, all I had to do was change the the modem to DMZ to the router and port forward as normal from there.

wish that netgear would have something similiar in their router instructions...

again, many thanks.