NTL Modem & Netgear Firewall

Netgear / Fvs336g
August 3, 2009 at 07:40:47
Specs: XP, 2GB
Hi Everyone,

Quick question, I have a NTL modem which is connected to my netgear pro-safe firewall then my computer upon others are connected to a switch.

I am looking to open some ports and forward them, all settings are ok and nothing seems to open (i.e. my DVR) i looked at the setting and the firewall is taking the ip address of the cable modem, so the ip address of the firewall states is: (which is the cable modem) but the real IP address i can see is on the cable modem.

I have tried setting the netgear up on the static ip address ntl gave me but then the internet stops working.

Any help would be fantastic.

See More: NTL Modem & Netgear Firewall

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August 3, 2009 at 09:29:11
"firewall is taking the ip address of the cable modem"

So what you mean is the cable modem is giving the firewalls wan port an ip address. That means the wan port is set to dhcp and the modem or a device beyond is suppling an ip address [dhcp server]

"the ip address of the firewall states is: (which is the cable modem) but the real IP address i can see is on the cable modem."

What do you mean by "real" ip address on the cable modem? is usually the LAN subnet [that is the side of the router the switch/pcs connect to]

ISP supplied static ips usually cost you more per month than the standard package. Have you talked to NTL about the static ip assignment on the wan interface of your router?

What exactly do you mean by internet stops working?

Can you ping the router lan and wan ips? Yahoo.com? Where in the chain is the break?

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August 4, 2009 at 01:03:03
Hi, Firstly, thanks for your response.

Yeah that's correct, the ntl cable modem is giving the netgear firewall an IP address from the cable modem.

When i say real IP i should have said the public IP. So, i log into the cable modem from and i can see the static IP address that NTL supplied (i am paying extra for the static) but the point im getting at is that the firewall should be getting the public static ip address shouldnt it & this is the reason why no services and ports if forwared will work.

When the internet stops working is when i change the Netgear firewall settings to the static IP and set it up as it should be, i.e. Internet IP Address: "Static IP" Subnet & gateway. Then when i press accept the internet will disconnect & i can ping the router & the IP address.

I hope this is enough info.

Sorry for the confusion.

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August 4, 2009 at 11:47:24
I know what you write makes sense to you... but you need to make sense to me if I am to help you.

For example you say you logon to the modem [so I am assuming you are direct connect to it from your pc] and you see the ip address you say you have been assigned.

WHERE do you see this? On the modems wan interface?

If this is the case the modem needs to be put in bridging mode so it passes that thru to the routers wan interface either by isp provide dhcp [check the modems wan properties] or static assignment.

You can not assign a subnet to the routers wan interface when the modems lan side is different at Router wan would be for example.

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August 5, 2009 at 01:09:20
The modem is connected to my WAN port of the Firewall router & then from a lan port into the switch.

the computer i am on at the moment is connected to the switch.

I log into the ntl modem & then see the static ip address that my ISP has assigned for me:


Gateway MAC Address: 00:02:8a:6e:5d:91

Internet IP Address: 86.**.***.***

Subnet Mask:

Default Gateway: 86.**.***.***



Gateway IP Address:

Subnet Mask: 255.255.255. 0

DHCP Server: Enabled

NAT : Enabled

Operating Mode: NAT mode

Private IP Range: through
Public IP Range:


Shouldn't the Firewall Router be picking the internet ip address up? At the moment this is how the firewall router looks:

Connection Type: DHCP
Connection State: Connected
IP Address:
Subnet Mask:
Primary DNS:
Secondary DNS:

Thank You.

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