Windows 7: Flaky TCP/IP or Ethernet Controller?

Just over a week ago I took delivery of a new Windows 7 PC I had built (Win 7 Pro 64-bit with a Core i5 3450)

The motherboard is a Gigabyte one with a Realtek Ethernet controller.

Have quite a few issues with DNS lookup failures (completely random) which I didn't have on the previous machine (XP Pro with Pentium D and Nvidia nforce networking) and am using a Netgear DGND3300 V2 on a wired link.

NAT is disabled as I have an IP block and the router is set to distribute this via DHCP. (also have an access point with Xbox and freesat units connected but they are not switched on.

Now on my previous system the first board it had had a Realteak controller and this exhibited the same behaviour until it died.

I've tried resetting TCP/IP, disabled DNS client service and even rebuilt the Windows install from the provided OEM DVD.

Also upgraded the drivers but this does not work, been back to system builder who say its a popular board and they aren't aware of iissues and suggested adding a network card if its not suitable for my network which is of course nonsense as Ethernet is an agreed standard.

So has anyone had issues with this chip (first board from old system was an Asus) or is Windows 7 a bit prone to this issue?

It's not gonna be a native WIndows problem.

Exactly what issues are you having besides DNS lookup? if your NIC was going bad it would be causing more issues than DNS, have you tried running a continuous ping for a while to see what happens?

What about an MTU issue perhaps?

Are the TCP/IP settings that its picking up from DHCP indeed correct?

Is the DNS pointing towards your router or your ISP, or something else?

Hi thanks for the reply.

DNS is set to auto so is currently using the router as a proxy, will try setting Zen's DNS servers in the network options.

router is indicating correct MAC for the board and this corresponds with the IP its allocated to the PC, will try a ping test tomorrow.

disabled all power saving for the NIC too.

Nothing else apparent.

Interesting. I'm having extremely similar problems.

Gigabyte A75M-D2H motherboard with onboard RealTek LAN and wired connection to Netgear DGND3300 v2 router. New Win7 install.

The other PCs in my home all work fine. Good speed, network map works, etc. But this new PC is slow, the network map won't show, frequently loses connection.

Tried downloading the most up to date drivers, etc but no luck.

Have you installed the latest RealTek drivers? Don't rely on Windows Update to do it for you.

In reply to a post by techguy:

The motherboard is a Gigabyte one with a Realtek Ethernet controller.
...
NAT is disabled as I have an IP block and the router is set to distribute this via DHCP. (also have an access point with Xbox and freesat units connected but they are not switched on.
...
suggested adding a network card if its not suitable for my network which is of course nonsense as Ethernet is an agreed standard.

Just to mention, although Ethernet is an agreed standard, this in no way means all network cards perform equally.

Network cards can have onboard processors which depending on their spec can have larger buffers and offload aspects of packet processing from the computer's CPU, most commonly header data such as checksums (cards for servers usually also handle stuff like VLANs and link aggregation onboard). Whereas cheaper cards (including some of the Realteks) interrupt your processor more often, especially at gigabit rates because they just pass more of the processing on.

However you would not usually notice this unless your computer has an older or slower processor while under high packet-per-second rates. I doubt it would account for intermittent DNS lookup performance.

How are you determining you have DNS lookup problems (a web browser error message that may mention "DNS" or "resolve" is just a generic cover-all message for any number of problems)?. I assume you have also tested the network patch cable or tried a few others.

At the very least you do a visual check for nicks into the cable and wiggle the cable and monitor if the speed / duplex glitches as an intermittent break in the cable would also cause a "cannot resolve this website host" type browser error.

You mention you have NAT disabled but also that you have an "access point". So how big is your public IP block as do you have enough public IPs for every wired and wireless device for the duration of the DHCP lease - regardless if the device happens to be off at some time. This would include smartphones, tablets and any visitors you happened to let on your Wi-Fi as a guest.

Is every other device (including the freesat) correctly picking up valid network settings (they might be expecting private addresses or otherwise causing a conflict)?

Personally for IPv4 I would be tempted to only have public IPs on the things that needed to run internet-facing services, which would not generally include mobiles or indeed Wi-Fi devices generally.

Edited by prlzx (Thu 30-Aug-12 21:34:31)

In reply to a post by micksharpe:

Have you installed the latest RealTek drivers? Don't rely on Windows Update to do it for you.

In addition, you can consider booting from a non-Windows CD. I'd expect nForce boards and/or Realtek network cards to be well supported on any linux live CD which would normally include a web browser and GUI "Network Tools" (as well as terminal network commands as standard).

If it's of any help, I have a Gigabyte GA-P55-USB3 which is fitted with a Realtek RTL8111E ethernet controller running Windows 7 Professional 64-bit. The network driver I use is Realtek version 7.48.823.2011 (23/08/2011) from file Install_Win7_7048_09162011.zip.

Apart from the fact that when installing Win 7 it didn't have a suitable network driver so I had to get one via my netbook. But since installed it's not given me any problems. LAN settings are all set to default / automatic.