Sorry, another NTL cable modem questin

landmonster

Hi there,

first post so forgive me if it's been covered tons of times before. I did search but didn't quite find the info I'm looking for.

I have broadband through an NTL cable modem which is connected to either my old, old iMac with no wireless card or I can use it with my iBook which does have a wireless card.

What I want to do though is have the cable modem connected to the iMac and then the wireless router connected so I can use the iBook wirelessly.

The cable modem has only got one ethernet port. The 3com router has 4 ethernet ports and was previously used as an ADSL router.

How do I configure it because NTL's technical support were about as much use as an ashtray on a motorbike?

Any help much appreciated.

Foxwood

landmonster wrote:

What I want to do though is have the cable modem connected to the iMac and then the wireless router connected so I can use the iBook wirelessly.

The cable modem has only got one ethernet port. The 3com router has 4 ethernet ports and was previously used as an ADSL router.

How do I configure it because NTL's technical support were about as much use as an ashtray on a motorbike?

Is the 3com router that was previously used as an ADSL router an actual ADSL router, or is it a broadband router that was plugged into a seperate ADSL "modem"?

If it's a broaband router, just plug the 3com into the cable modem, and connect the iBook and iMac to the 3com. If it's actually an ADSL router, then it's probably not going to work for you.

landmonster

Foxwood wrote:

Is the 3com router that was previously used as an ADSL router an actual ADSL router, or is it a broadband router that was plugged into a seperate ADSL "modem"?

If it's a broaband router, just plug the 3com into the cable modem, and connect the iBook and iMac to the 3com. If it's actually an ADSL router, then it's probably not going to work for you.

It's an ADSL router so I don't have anything to plug the ethernet cable from the cable modem into apart from one of the 4 LAN ports at the back.

I assume I need a new piece of kit so if anyone had any suggestions for that I'd appreciate it.

Foxwood

landmonster wrote:

It's an ADSL router so I don't have anything to plug the ethernet cable from the cable modem into apart from one of the 4 LAN ports at the back.

I assume I need a new piece of kit so if anyone had any suggestions for that I'd appreciate it.

The Linksys WRT54G is widely recommended. Personally I'm a fan of D-Link - I'm using a DI-524 at the moment.

irlrobins

I really should add an FAQ about ntl and dsl routers. What's the correct answer? "No, it won't work. It will only act as a switch, not a router"? That a good summary?

Foxwood

irlrobins wrote:

I really should add an FAQ about ntl and dsl routers. What's the correct answer? "No, it won't work. It will only act as a switch, not a router"? That a good summary?

If you have a "wired" router (on any broadband service) that already handles NAT and DHCP etc, and you happen to have a wireless "ADSL Gateway" lying around, you can use that as a Wireless Access Point by just using the LAN ports - traffic comes in on a wireless port, and is delivered to the "wired" router, which the ADSL box just sees as another LAN device. The "ADSL Gateway" never does any routing, because, as far as it's concerned, it only sees "LAN" traffic. (A diagram might help, but I can't draw to save my life!)

As I understand it, the NTL modem isn't a router - it doesn't do NAT, and it doesn't allow you to have multiple devices connected via a switch/hub. And the ADLS router will ony route from it's LAN ports to it's WAN port - and you can't plug the WAN port into the NTL modem, because it's an ADSL port, not an ethernet port.

Botttom line, you need a "Broadband router" with NTL. You can't use an "ADSL Gateway/Router" with an NTL modem (or with the equipment provided by most "Wireless Broadband" services).

landmonster

Thanks all for your help. Much appreciated.

landmonster

landmonster wrote:

Thanks all for your help. Much appreciated.

*bump*

Ok, I now have a LinkSys broadband router.

I have the cable modem plugged into the router and then the router into the iMac.

The network control panel shows I'm getting an IP address provided by the DHCP server but I don't have any internet connection.

The config page in the router has space for a host name and a domain name. Do I need to fill in anything here?

Also, at the bottom there is space for static DNS. I assume these would be NTL's dns servers but I can't find them anywhere on their website. Does anyone know what they are?

Thanks.

landmonster

Update: Just noticed the IP address is not being provided by the server. In the setup page of the router it asks me for a starting IP address based on the IP of the router.

The router's IP is 89.100.10.1

The starting IP looks like this: 89.100.10.x where x = a value I put myself.

If I put 50, for example, that's what shows up as the DHCP IP in my network control panel. If I put 200 that's what shows up.

So the router doesn't seem to be obtaining the DHCP IP from the cable modem or my config is wrong.

Anyone?! Please?!

Foxwood

landmonster wrote:

The config page in the router has space for a host name and a domain name. Do I need to fill in anything here?

No.

Also, at the bottom there is space for static DNS. I assume these would be NTL's dns servers but I can't find them anywhere on their website. Does anyone know what they are?

The router should be getting an address, and DNS settings automatically from NTL - you should not be setting them manually.

If your router isn't "logging in" to NTL, turn off the NTL modem for 15 minutes and then try it again - apparenly, the NTL modem remembers the MAC address of the device it's connected to and won't talk to another device.

landmonster

Foxwood wrote:

If your router isn't "logging in" to NTL, turn off the NTL modem for 15 minutes and then try it again - apparenly, the NTL modem remembers the MAC address of the device it's connected to and won't talk to another device.

That didn't work either but thanks for the reply.

What did work was noticing the 'automatic set-up' button on the front of the router which sorted everything out :rolleyes:

Thanks again.

dloob

Foxwood wrote:

As I understand it, the NTL modem isn't a router - it doesn't do NAT, and it doesn't allow you to have multiple devices connected via a switch/hub. And the ADLS router will ony route from it's LAN ports to it's WAN port - and you can't plug the WAN port into the NTL modem, because it's an ADSL port, not an ethernet port.

Botttom line, you need a "Broadband router" with NTL. You can't use an "ADSL Gateway/Router" with an NTL modem (or with the equipment provided by most "Wireless Broadband" services).

Just a quick note on this.
I had NTL working with my old ADSL router.
I disabled DHCP on the router, connected the modem to a lan port.
The modem assigned an ip to devices that connected over the wireless or those connected to another of the lan ports,
It doesn't seem to do NAT as such as everthing got a public internet from the range registered to chello.
But it was routing everything correctly.

So my connections were
modem to router lan port.
PC to router lan port.
Laptop over wireless.
DHCP on router disabled.

I have since changed to a Broadband router to give me more controls over things.
All the ADSL routers firewall settings etc. are bypassed by the setup I had as the router thinks it's all lan traffic.

Foxwood

dloob wrote:

It doesn't seem to do NAT as such as everthing got a public internet from the range registered to chello.

In the past, NTL users stated that the NTL cable modem would only provide a single IP address - that you couldn't plug multiple devices in without using a NAT router to share a single IP address between mltiple devices. I don't hve access to an NTL account at the moment to confirm whether or not that is the case.

I would also suggest that it's foolhardy for anyone to plug a computer directly into a broadband service, without using a NAT router. There are enough zombie PCs out there already.

(This is one thing that the Irish DSL market got right from very early on - the supplied customer equipment used NAT from pretty much the beginning of DSL in Ireland. It's scarey to see that the wireless providers didn't learn anything useful from that - it'd be interesting to know how many users of "wireless broadband" have been hacked in the last year or so, because they are wide open to inbound connections from the 'net).

dloob

I have the NTL:250 modem.
I noticed this setting on the modems operation config page
Maximum Number of CPEs : 3
I think it means up to three devices may connect through the modem.

I was surprised at the lack of NAT too, I imagine that a lot of NTL modems are connected to pcs without even a software firewall.

antoinolachtnai

I believe that setting things up in this way (i.e, without NAT) is what is recommended by the DOCSIS and other relevant international standards.

In many ways it is tidier than delivering as NAT from the point of view of a network engineer, but you make a very good point as regards security for the average home user.

hightower1

landmonster wrote: »

Hi there,

first post so forgive me if it's been covered tons of times before. I did search but didn't quite find the info I'm looking for.

I have broadband through an NTL cable modem which is connected to either my old, old iMac with no wireless card or I can use it with my iBook which does have a wireless card.

What I want to do though is have the cable modem connected to the iMac and then the wireless router connected so I can use the iBook wirelessly.

The cable modem has only got one ethernet port. The 3com router has 4 ethernet ports and was previously used as an ADSL router.

How do I configure it because NTL's technical support were about as much use as an ashtray on a motorbike?

Any help much appreciated.

Well ass, If you knew more about i.t than sarcasim you would know that your enet port on your modem can link to the wifi router and from there use another enet lead to the pc tower and connect then wireless with the ibook?????? From there out ntl only give you net access so why would they be able to help you with a router YOU bought? Thats like taking your car to the dealership cause your new panasonic radio doesn't work?
Use the sarcasim when its needed not just when you dont get the facts ok.

irlrobins

And you raised a year old thread just to give abuse? You're the ass. A banned one at that.