BT Broadband services and Netgear FVS318G

[xlrtech]

I have a Netgear FVS318G firewall router, which I am in the process of setting up. Testing it in my home environment, I connected it to a BT Home Hub 3, which is connected to the BT Infinity service; I get 37mb/sec on this connection.

The FVS318G can deliver two separate LAN connections, using the main LAN ports for the first, and a DMZ port for the second. The purpose of this arrangement in my project is to offer internet access to two separate groups of users, while denying them access to each other's LAN. In my home test, this worked perfectly.

I then took the router to the target environment, and set it up in exactly the same way. However, although the LAN connection and the DMZ connection functioned correctly, the internet connection was not delivered to either, as the FVS318G did not appear to register the WAN; the principal difference is that in this case, the internet connection is coming from a Netgear DG834v5 router, with a connection speed of around 1mb/sec.

The WAN port on the FVS318G appeared to pick up the signal from the DG834v5, but occasionally seemed to drop it. The WAN monitoring section consistently showed the connection as DOWN.

Can anyone shed light on this, as I've run out of ideas.

 

[overdrive31]

Did you authenticate both connections with BT using PPPoE? If you're trying to do the same thing using DHCP, it will not work.

 

[xlrtech]

I have not altered the settings on the BT Home Hub, which (AFAIK) uses PPPoE as standard. When the FVS318G recognises it (using Auto Detect), it shows "DHCP source detected".

On the DG834v5, I also used PPPoE (although BT Business Broadband recommends PPPoA). This router is set up not to use DHCP, as I wish the devices on this LAN to have fixed IP; however, I had thought of changing this to see if it made a difference. If I understand you correctly, this will not work.

Is the low speed of the broadband connection a factor? Or is it possible that the DG834v5 not a suitable device for connecting to the FVS318G?

 

[overdrive31]

Could be, there is a IP address conflict. What subnetwork do the two use? If the Home Hub uses PPPoA, chances are it is bridged and would work. The difference being, the DG834v5 is NAT routed, not bridged, and in that case it will not work.

 

[xlrtech]

Thanks for your help on this. My networking expertise is limited (I'm learning!) - but your comments have made me realise that the smart thing to do is test my Home Hub at the target site, and if it works, get one (ebay has loads) and deploy it there.

 

[overdrive31]

Might just be an IP conflict, the default IP for the BT Home Hub is 192.168.1.254, the FVS318G default is 192.168.0.1, and the DG834v5 default is also 192.168.0.1 and conflicts with the FVS318G. Try changing one of the Netgear's to use something like 192.168.2.1

 

[xlrtech]

I tested the FVS318G with different ranges to ensure that I would not have IP conflicts, so I don't believe this is the issue.

 

[xlrtech]

Today I tested your IP theory and my router swap theory; IP theory didn't produce a result - router swap did. Plugging in a Home Hub at the target site produced an instant, sustainable connection, so that's what I'll be doing.

Thanks again for your help, much appreciated.