[MLB-WIRELESS] [OT] Vista desktop can no longer connect to Internet via Netgear CGD24N cable gateway

[Michael Borthwick]

On 29/10/2011, at 10:17 AM, Denis Cheong wrote:

> My thoughts ...
>
> 1. Delete ALL NICs from Vista, reboot and allow them to be re- 
> detected from scratch.
The NIC (there is only one) is onboard.

>
> 2. Uninstall all NIC drivers from Vista, and install only the  
> original ones you want (having conflicting drivers installed can be  
> an issue because you don't know which ones it's using)

Already tried - with new drivers from the Acer website. But note that  
the problem persists when booted into Linux on the PC. Can't get a  
direct lease anymore (regardless of OS).
>
> 3. Ensuring that when you set a static IP address you also set a  
> default gateway.
Good suggestion but I'm using DHCP - I will have another play with  
static IP's though if you think it's worth it.
>
> 4. When you have a static IP address, doing a tracert to see where  
> packets are dropping out.  Also ping other machines on the same  
> subnet.
There are no other machines on the subnet - I have only created the  
subnet as part of the test methodology - to create an opportunity to  
insert another networking device the PC and the Netgear- but I could  
put another machine on the subnet to try. It has no problem pinging  
the RB.
>
> 5. On the Mikrotik (or another linux machine), in the same layer 2  
> network, doing a Torch (or tcpdump) to see if any packets are  
> getting onto the network from the PC (DHCP specifically)
OK that's good thinking.
>
> 6. Replacing the patch / flylead cables, or connecting with a  
> separate cable directly to the switch
>
> 7. Doing a cable fault test on the switch (if it has one) or on the  
> NIC (if it has it)
OK. I will look into testing the switch. Not sure how to do a "cable  
fault test" on an onboard NIC. Note that that connectivity is fine  
when going via the RB. Would seem to indicate the NIC is fine and the  
setup was working fine for around 6 months before the spontaneous  
failure of connectivity.
>
>
> If the PC can get a lease from the RB but not the cable modem, this  
> says to me that in reconfiguring the physical layout you eliminated  
> the point of failure (most likely one of the cables), i.e.
> 	• Did you patch the PC directly into the RB with a different patch  
> lead?
no. I am using the same lead that previously went from the PC into the  
wall - suggesting it's OK.
> 	• Was the RB using the PC's old network cable to get to the switch?
no. a different cable.
> 	• The 532 is only 10/100 - was the Acer previously running gigabit  
> to the switch?
no. the one and only NIC is onboard and is only 100Base-T
> If so by putting the 532 in between you have just dropped out two of  
> the pairs on the ethernet cable, one of which could be faulty, and  
> would explain why the 532 eliminates the issue - try dropping the  
> NIC back to 100mbit if you can't test the cable.
thanks good thinking but I'm only ever adding extra h/w - never  
eliminating anything - so I'm only adding points of failure. Unless  
something is cancelling something else out - like a cross-over issue.

Really appreciate your input Denis.

Cheers,

Mike