Connecting new computer to existing ISP

Fanny Cradock

I was wondering how i would go about connecting a new laptop to my existing BB connection. I assumed that it would be as simple as placing in the ethernet cable, but alas....

irlrobins

TBH

Fanny Cradock

both my desktop and new laptop run xp home sp2. what else do you need to know?

irlrobins

Who is your ISP?
Are you connecting to modem/router using wireless or ethernet cable?
What error messages do you get?
Do you assign ip address by dhcp?
Do you get an IP address, etc?

Etc.

28064212

For a start, who's your broadband provider?

Fanny Cradock

ok, i see now that i'm missing some info. my apologies!

ISP: NTL.

Connection: via modem with ethernet cable.

Error: limited or no connectivity.

Not sure what dhcp is - though i've not changed any settings.

when i run "ipconfig" i get:
nothing for connection specific DNS suffix;
i DO get an auto-connection ip address and subnet mask;
and again nothing for default gateway.

when i try renew the ip it is unable to connect to the dhcp server.

irlrobins

Switch off modem for 10-15 mins. Connect it to new PC, then switch PC on. Switch modem on. See if it gets an ip now.

yoyo

Have you installed the cd accompanying your router?, your NTL details should be saved in your router but the pc will need your router software installed, this is deffo the case with my Eircom Netopia router

Hope this helps

Nick

irlrobins

Nope, entirely different setup. I think the problem is that the modem assigns an ip address according to mac address. So the ip is linked to the mac address of the old PC. By switching off the modem for a period of time it will forget this mac address/ip association and will assign an ip to the new mac address that it connects to on restart.

edit: Some info about the above taken from Microsoft Xbox connection guide.

Cable Modems
The majority of cable service providers offer their customers devices that are configured
to provision one IP address to one device (for example, an Xbox or a PC) in a user’s
home. These devices provision an IP address to the first Ethernet MAC address the
device “sees” or is connected to. That MAC address will be written to the internal table of
the cable modem and that MAC address will always be able to connect to the provider
network. Given that only one entry in the table is allowed, to connect a new or different
user device to the provider network, the entry within the cable modem table must be
updated.
Cable modems that fall into category one (as defined above) accomplish this table
updating by simply powering off the cable modem. As an example, Data Over Cable
Service Interface Specification (DOCSIS) cable modem plants follow this protocol. The
time a cable modem must be powered off varies amongst cable modems. In most
cases, however, powering off the cable modem for five minutes performs a full clearing
of the internal MAC address table. Once the table is cleared, a new user device (PC or
Xbox) can be connected to the cable modem. The new user device will populate the
MAC address table in the cable modem and receive an IP address from the provider.
Category two cable providers (User IP Reset/Release) present a different set of
challenges for users. These providers have cable plants that do not release their IP
addresses upon cable-modem reset. Instead, they require that a user gracefully release
the IP address from any device that has been provisioned with an IP address. To
accomplish this task, the user must engage the winipcfg utility (for Win9x and Millennium
PCs) or type (from a command prompt) ipconfig /release for Windows NT, 2000 and XP
based PCs.

There is no way to manually perform an IP release on the Xbox console. Therefore,
if a user has a category two service provider and his or her Xbox (not his or her PC) has
received an unwanted IP address, the user must contact his or her service provider to
release the address.
Category three cable providers (Service Provider IP Reset/Release) also have cable
plants that do not release their IP addresses upon cable modem reset. However, unlike
category two providers, the customer must contact the service provider to remove the IP lease from the cable system for any device (including PCs).

Fanny Cradock

thanks! it was as simple as unplugging the modem for a few. should have figured that out myself

irlrobins

Don't NTL modems come with a sticker on them saying something like "if you have a problem, switch modem off then on again as this resolves most problems"?

mac_leinn

irlrobins wrote:

Don't NTL modems come with a sticker on them saying something like "if you have a problem, switch modem off then on again as this resolves most problems"?

Every piece of electrical equipment should have a sticker like that