Vista - Sudden loss of internet connection

About 5 days ago, I lost internet connectivity on my Vista Premium desktop
machine. This is an older, hand-built machine with a MSI Neo-4 motherboard,
NVIDIA nForce 4 chipset. I've been using the built-in NVidia NIC. Vista has
been on regular updates so I believe I just got the SP1 update a week or two
ago. This setup has been working flawlessly for about 6 months.

My network hardware consists of a Linksys WCG200 cable router (firmware
1.1.2.9.4-1104) and a WRT54G router (firmware 8.00.2). The WRT54G is
operating as an AP/router, hardwired (ethernet cable) into the WCG200 (which
is in the basement). I had to do this because the wireless range on the
WCG200 just wasn't enough to reach the top floor of my house. This desktop
is wired directly to the WRT54G. It is the only active wired connection into
the router. All other machines in the house are connecting wirelessly and
have no issues with internet connectivity. All other machines are XP, this
desktop is the only Vista machine in the house.

From this desktop, I can reach the admin interfaces for both routers
(192.168.0.1/wcg200 and 192.168.0.200/wrt54g). From the ipconfig output I
post below, it looks like the desktop is receiving a DHCP address of
192.168.0.105 (the wrt54g is set up to assign addresses from 100 to 149)

From IE, I tried the "diagnose problem" link and I believe I get "the domain
name server could not be found".

I assigned DNS addresses to the IPV4 interface - no change.

I assigned DNS addresses in the wrt54g router - no change.

I used System Restore to restore to a previous known working point and each
time received errors that the restore point was not successful.

I have restored from a working backup (prior to the connectivity problem).
When the system rebooted, the safe mode screen appeared so I chose "safe mode
with networking". CONNECTIVITY WAS RESTORED at that point. I then rebooted
normally and then CONNECTIVITY WAS LOST. Same errors. Rebooting into safe
mode, connectivity is STILL LOST.

I rolled back the NVIDIA ethernet driver - no change.

I disabled the Vista Firewall - no change.

Using Control Panel, Network and Sharing Center, I see the picture of my
computer, my network and the Internet. There is an X between "my network"
and Internet. Clicking on "my network", I get a new window and I can see the
other computers in my house.

From ipconfig /all:

Ethernet adapter Local Area Connection 2:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Bluetooth PAN Network Adapter
Physical Address. . . . . . . . . : 00-10-60-E9-E3-5A
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes

Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : NVIDIA nForce Networking Controller
Physical Address. . . . . . . . . : xx-xx-xx-xx-xx-xx
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::7141:445d:3f60:8f28%8(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.0.105(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : Monday, April 28, 2008 7:50:14 PM
Lease Expires . . . . . . . . . . : Tuesday, April 29, 2008 7:50:14 PM
Default Gateway . . . . . . . . . : 192.168.0.200
DHCP Server . . . . . . . . . . . : 192.168.0.200
DHCPv6 IAID . . . . . . . . . . . : 201608064
DNS Servers . . . . . . . . . . . : 192.168.0.200
NetBIOS over Tcpip. . . . . . . . : Enabled

Tunnel adapter Local Area Connection* 6:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft ISATAP Adapter
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Local Area Connection* 7:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
Physical Address. . . . . . . . . : 02-00-54-55-4E-01
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Local Area Connection* 9:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . :
isatap.{F91FD099-9BE1-4654-9BE6-356E6875B
0B9}
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes

did you try assigning your ISPs DNS addresses statically to the
connection as well as the local gateway address of 192.168.0.200?

On Tue, 29 Apr 2008 01:01:01 -0700, Paul
<Paul@xxxxxx> wrote:
--

Barb Bowman
MS-MVP
http://www.microsoft.com/windowsxp/e...ts/bowman.mspx
http://blogs.digitalmediaphile.com/barb/

You say you could not do System Restore.
Are you using Norton?
Norton stops SR, and also can block all Internet connection!
--
Mick Murphy - Qld - Australia


"Paul" wrote:

Thanks for the replies. Norton is out of the picture because this PC was
installed with an OEM version of Vista. I double-checked the DNS addresses
and found that they weren't working. I regained connection - here are the
steps I took:

1. Assigned proper, working DNS addresses to the router (wrt54g) - no change
2. Assigned same DNS addresses to PC - no change
3. Assigned static address to PC with gateway assigned to cable router
(wcg200) - works!
4. Changed PC config to have gateway assigned to router (wrt54g) - no
connection
5. Changed PC config back to DHCP and dynamic DNS, connection good.
ipconfig /all shows that dns addresses have been changed (first two nodes are
the same)
6. Reboot - no connection
7. Set config back to Step 3 and leave it.

Note that I cannot assign DNS addresses in the WCG200. Although my guess is
that I'd be able to if I switched to static routing on that unit. Any reason
why DHCP and dynamic DNS stopped working? This happened after I created a
full backup of the machine.