Help needed with NTL cable modem, OS X and iMac

Dazzla

Dazzla

Icon specialist
My iMac came today so I've been playing around with it, then I decided to get it connected to the net. At the moment, I have a 64k cable modem, connected to my ethernet port on my laptop. I turned off the laptop, unplugged the power for the cable modem for a few minutes, plugged the ethernet cable into the iMac, plugged the power back in to the cable modem then powered up the Mac.


Now the iMac is set to DHCP in network preferences and all 3 lights (power, cable and PC) are all on, on the modem itself.

When I start up the mac, it hangs a bit on "initialising Network" (or something like that) and then proceeds t boot as usual.

Can anyone help me here?


Thanks

Dazzla
 
When it's initializing the network at boot up, it's actually talking to your cable modem servers to get it's DHCP info. There is nothing you can really do to speed it up as it really depends on your cable company's servers. My advice is to just not shut down so it doesn't have to go through the boot up daily.
 
How long is the hang? I use NTL, and I don't really notice any problem with a delay.

Are you using the surfboard? (that is the one that NTL supplied me). If so, then it acts as a DHCP server itself. When you turn on the cablemodem, it will login to NTL. When you turn on your iMac it will login to your cablemodem, not NTL, which should keep things quite quick. Make sure that all the lights are lit on your cablemodem before turning on your iMac.

NTL is made up of many companies and networks in reality, so your service may be slightly different to mine.

Roger.
 
The problem isn't with the booting, it's a problem I had before when trying to use the cable modem on another PC. It's as if the XP laptop isn't releasing it properly.

I get a problem where on any other computer the IP address begins with 169, This isn't a valid IP address for NTL.

the IP address on my Laptop is always the same and begins with 80


Is there a way to release the IP address from XP, I know there was on 9x (I suppose this is the wrong forum really).


But is there anything I need to do additionally to the iMac settings other then set it as DHCP?
 
Dazzla

I don't know if this will be any help as I'm not sure that you have the same set-up as me. I'm using a broadband connection via an ethernet cable through NTL's cable TV box which gives me a 512K connection. Like you I sometimes need to connect a Windows XP laptop up instead of my iMac. The importent thing is that after I connect the laptop to the cable, I have to disconnect the cable box from the mains power for 40 seconds or so, then plug it back in. After that it always works fine. I then have to do the same thing after re-connecting the iMac. I'm guessing the reason is because the cable box remembers the address which is hard-coded into the network cards or adapters in each machine. Resetting the box causes it to re-check the number.

BTW. To release the ip address in XP enter

ipconfig /release

into a dos box.

The 169. x.x.x address is a 'default' address that the machine selects for itself if it can't talk to a valid DHCP server. The correct address you should be given is a class 'A' 80.x.x.x address as you have already found.

The 'hang' for a few seconds on startup, as dricci correctly states is the machine negotiating either a new ip address or renewing and existing lease with the DHCP server.

Hope this helps
 
It isn't that XP is holding on the IP, it is the lease on the cable modem.

As I already mentioned the cable model also acts as a DHCP server. This means that is will distribute IPs to the computers attached to it. These are distributed on a lease basis associated with the network adapter's MAC address on each computer. These leases are granted for a period of time (configurable normally).

I think that what is happening is that the cablemodem is granting the IP to your laptop, but when you plug another computer in (with a different MAC address), it cannot give any more IPs away (because none are available) so you get the default 169.x.x.x. Turning off the cablemodem for 40 or so seconds may clear the lease information and allow another computer to be re-assigned.

The delay may be that the cablemodem is negotiating with NTL for another IP, but is not being granted one (you are only allowed one).

It is a good idea to release the IP from the XP machine - perhaps you could set the DOS command to be a logout or shutdown script? Might save you some typing.

Hope that this helps,

Roger.
 
hi

have had the same problem, rang ntl and they said that the ip address is changed every 4 hours to you have to plug in the modem to the imac and have everything switched on, and when the ip address is released the modem will work. Its a pain ti have to wait up to 4 hours but ntl don't seem to know any other way.
 
The is with win XP they do not release the IP properly. Plug it into the mac and you have to wait at least three hours until it starts working there. I know what as i used to have to do the same thing!
 
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