Member Avatar for Chico13

Hi,
I'd be really pleased if someone could give me guidance on this problem.
I'm trying to connect a Dell Inspiron laptop to my friends NTL/Virgin cable modem.
I took it to my local computer shop, who supplied and installed a Pluscom 10/100 PCMCIA adaptor card, plugged in their ethernet cable and demonstrated internet connection ok.
Brought it home and plugged an ethernet cable into my Belkin router and connected to the internet ok. Took it to my friend's and plugged in the ethernet cable which goes from her cable modem to her PC and - no connection. Back to mine and did the same - plug in direct from the modem - no connection.
I've aslo tried a Ten base-T ethernet hub and an Ethernet/USB adaptor which I had lying about and I can't get any of them to connect to the internet direct fron the cable modem,although the USB/Ethernet adaptor works fine when connected via my Belkin router. Is this something to do with the fact that my router has its own IP address, whereas the PCMIA adaptor and USB/Ethernet link don't ?.
The laptop is running Windows 2000 SP4.

Thanks in advance for any help on this,

Chico

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Two different fixes appear in the replies: one pointed at a browser-level setting () and the other at a system-level network configuration (). Both show this type of problem is often not a faulty cable or NIC but a mismatch between what the modem/ISP expects and what the laptop is presenting. The notes below give a concise troubleshooting path and what to watch for next time a machine works behind a router but fails when plugged straight into a cable modem.

Quick diagnostic checklist to run before changing hardware or swapping adapters:

  • Verify the physical link lights on the modem and the PC adapter when you plug in the cable.
  • Check the TCP/IP state so you know whether DHCP succeeded or failed.
  • If DHCP failed, try releasing and renewing the lease and then power-cycle the cable modem (the modem often needs to forget the previous device).

Useful commands (run from a command prompt):

ipconfig /all
ipconfig /release
ipconfig /renew

What to look for in ipconfig /all: a valid IPv4 address (not 169.254.x.x), a default gateway, and a DHCP server address. If the client shows a 169.254.x.x address, DHCP did not respond and the problem is upstream (modem/ISP or cabling). If DHCP succeeds when behind the router but fails when direct, the modem may still be holding the previous lease or the ISP may restrict registration to a single MAC.

Other practical items to try: test the laptop with another known-good modem, update the PCMCIA/USB NIC drivers, temporarily disable extra network adapters or VPN/virtual adapters, and check for firewall/third-party security software that could block traffic. If the ISP enforces a single MAC, either power-cycle the modem when switching devices or use MAC cloning on a router.

If these checks still leave the connection broken, capture the ipconfig /all output and compare it between the router-connected and modem-direct cases to isolate whether DHCP, gateway, or driver behavior is the root cause.

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Member Avatar for confusertech

This is what I had to do in Internet Explorer:

Go to Tools at the top of the page
Internet Options
Connections Tab
LAN Settings
UN-CHECK Automatically Detect Settings

Member Avatar for Chico13

This is what I had to do in Internet Explorer:

Go to Tools at the top of the page
Internet Options
Connections Tab
LAN Settings
UN-CHECK Automatically Detect Settings

Thanks for that - it set me thinking as to why Firefox wouldn't work either. Anyway I finally stumbled across Properties by right-clicking on My Computer which revealed a Network ID tab, then Network ID button which opens a Wizard, which reveals that the lap-top had been set up for an office network. Selecting the button for Home Computer - solved the problem.
:) Happy Bunny !

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