Broadband works on one PC - not on other!

[DragonQ0105]

Hey, I have a PC and Laptop. I just reformatted my PC last night and reinstalled XP Pro SP2. I cannot get the internet to work correctly. If I install the Modem and activate the connection, it gives no errors and everything seems to be fine. However, when I go to google or any other site, it stays at "connecting to xxx.xxx.xxx.xxx" for 10 seconds or so, then it works.

Then, I can normally have the internet working for about a minute (although it's slow), then I'll just get "Page cannot be found" for everything. It's not even TRYING to find the site I don't think - it comes up straight away.

Sometimes resetting to modem gets it working slowly for another minute or so, then it happens again.


Strangely, when connected to the Laptop (also with XP Pro SP2), it works fine.

Here's some more specific info:

PC:
- MSI KM2M Motherboard
- AMD Athlon 1700+ (266MHz FSB)
- 512MB PC100 SDRAM
- 64MB GeForce2 MX 400 Graphics Card
- 52x52x32 CD-RW
- 50x CD-ROM
- 19GB 5400RPM ATA100 HDD
- 75GB 5400RPM ATA100 HDD
- Netgear Ethernet Card
- On-Board LAN Ethernet
- 6x USB2.0 Ports

On the PC, I've tried:
- Connecting to the Ethernet Port on the Netgear Card
- Connecting to the Ethernet Port on the Motherboard
- Connecting via USB
- IE6 SP6
- Firefox 1.2
- Uninstalling + reinstalling the modem and ethernet interfaces
- Disabling + Enabling the connection many times
- Repairing the Connection many times

No luck.

Laptop:
- Toshiba Satellite Pro 4320
- 6GB HDD
- 32x CD-ROM
- 1x USB1.1

Works perfectly on the laptop, suggesting something is wrong on the PC. However, I've tried all 3 available drivers on BOTH computers (Windows XP ones, the ones on the CD they gave me, and the updated ones on the internet - that are supposed to fix "intermittent connections"!!). They do not affect it at all.

Oh, last thing, it's a Scientific Atlanta WebStar 100 Series Modem on Blueyonder 1Mbps Broadband. I've tried Blueyonder's phone help when I had a similar problem before, and they were useless and told me they couldn't think of anything else to fix it than what I'd already tried.

Can anyone here help me please??

 

[DragonQ0105]

What does that have to do with the fact that it was working before the format, and not after?

 

[LloydSev]

That's what I would lean towards.. but very odd as he can ping the sites..

Computer/Network Technician
CCNA

 

[LloydSev]

I think what he's saying is, he would like you to try to change your MAC to match your laptop's to see if it works.

Computer/Network Technician
CCNA

 

[DragonQ0105]

1) What is the MAC Address of the Laptop? Is it the part that says "Physical Address" when I do 'IPCONFIG /ALL'?

2) How do I go about changing this on the Desktop?

 

[LloydSev]

yes, it would be the physical address.

In UNIX it is just as simple as adding a line into the config..

in windows is requires the use of a 3rd party app.

http://www.klcconsulting.net/smac/smac12_download/SMAC12_Eval.exe

This is an evaluation version. Obviously you don't have to buy it to test this theory once.

Computer/Network Technician
CCNA

 

[DragonQ0105]

That program won't work. I cannot change the new MAC Address that it assigns to the Card...it's stuck at the default 0C-0C-0C-0C-0C-01. Maybe because it's an evaluation version?

 

[bcastner]

What matters is what the cable system authentication system wants.

See my earlier notes.

 

[DragonQ0105]

What? I cannot change the MAC Address with the program that was suggested...so what can I do?

 

[LloydSev]

iptables can do this for you, though frankly I have never had the need to spoof a MAC addy so I'm not entirely sure how to do it. If you can get iptables to do it for you then it probably wouldnt be too hard to make a shell script that brings up the interface and a different mac address, keeping in mind the advice above.

From another forum. BTW, IPTables is a firewall program.

Computer/Network Technician
CCNA

 

[DragonQ0105]

OK well it seems it's not necessary...both Physical Addresses are already the same. It appears the MAC is determined by the actual Modem since it's connected via USB, so it's the same on both PCs.

It seems MAC is not what's causing the problem....

 

[LloydSev]

You've verified that both MAC addresses are physically the same?

Computer/Network Technician
CCNA

 

[DragonQ0105]

Yes

 

[bcastner]

The MAC addresses are not going to be the same. If you do an ipconfig /all look for the line "Physical address"

 

[LloydSev]

he's using the USB connection from the modem to the computer, it is possible that the MAC could be from the modem could it not?

Computer/Network Technician
CCNA

 

[bcastner]

On a cable system the modem will be queried for the end point MAC address of the connected workstation, so the modem MAC is not in play here.

 

[LloydSev]

ok making sure..

so the question is.. what MAC address is it responding with if it's using a USB connector?

Computer/Network Technician
CCNA

 

[gx3]

Has anyone bothered to ask the modem what it thinks is going on. I think you will find therein your mac address answers.

 

[LloydSev]

ask the modem?

I think he should call his cable company to make sure they don't filter based on first MAC after the cable modem.

Computer/Network Technician
CCNA

 

[bcastner]

An excellent question, for which I have no good answer. Note though the original posting:

"On the PC, I've tried:
- Connecting to the Ethernet Port on the Netgear Card
- Connecting to the Ethernet Port on the Motherboard
- Connecting via USB
- IE6 SP6
- Firefox 1.2
- Uninstalling + reinstalling the modem and ethernet interfaces
- Disabling + Enabling the connection many times
- Repairing the Connection many times
"

What matters to most cable systems is that whatever MAC address was first used, can be identified at startup unless you call them and change it. Some cable systems have web pages to make this easier. Around my area, you can unplug (do not use the power on/off switch) the cable modem itself and wait an hour. Do a cold restart of the modem and it will re-read the new MAC for the attached PC and re-authenticate. In most areas you need to all tech support for the cable company. This is why way earlier I suggested to the user to purchase a broadband router and use its "cloning" feature to avoid this p.i.a. behavior.

 

[aquias]

Okay, let's try this, I doubt we'll see anything differnt but who knows.

Go to Network Places and right click on the cable connection, choose status, and then click on the details button. The top line will layout the MAC address. Verify whether or not these two addresses are the same.

As for me, I'm still not sold on this being the problem. If this was an issue of traffic being denied based on MAC address, his ping wouldn't work, filtering out a connection based on MAC address should allow no traffic not just deny specific port traffic (in this case traffic moving over port 80).