Extremely Frustrating Network Problems

Combat squirrel

Combat squirrel

Combat squirrel

Soldato
Joined
7 Aug 2004
Posts
11,263
Hi all,

My main PC is connected to a 1gb switch (which is connected to my server, and other hard wired PC's)

All the other PC's run at 1gb no problems, but my main pc just IS NOT playing ball, the network issues are as follows:

1) If I connect with my Z77 Extreme 4 As rock (broadcom netlink) the internet runs at 3mb down 20 up - yet it is network connected at 1gb and I can transfer files from server at 90-100MB/sec (as expected).

2) If I connect with my intel gigabit CT PCI-E desktop adaptor it works ok for like a day, then the internet crawls to a halt and its 3mb down again, then the network just crawls.

3) I recently had all sorts of the well known issues with intel gigabits on my server also and so i installed from OCUK a TP-LINK TG-3468 PCI-E x1 adaptor in server......works perfectly (server 2012)

4) So all the WEIRD problems with the onboard internet running slow on my main rig, Ii got one yesterday for my main rig (TP-LINK TG-3468), this seems to now ONLY connect to the network at 100mb....... :mad: I have tried FORCING it to connect at 1gb and it just goes into a cycle of saying the network cable is unplugged for 30 seconds until if finally connects again at 100mb.

5) I connected a 2nd network cable to the on board broadcom and enabled it again and not ITS only connecting at 100mb, I forced it again, same result no connection as it trys to connect then defaults to 100mb again.

I have updated ALL drivers on ALL cards, I assume the intel card is the one suffering with the known intel bug so scrapped that.

What on earth is going on with my network?

FYI I have tried both network cables on my laptop and it instantly connects at 1gb and the internet runs at 77 down 20 up as expected.

What the chuff is wrong with my pc ? tried forcing it, tried drivers whats wrong? :(




EDIT: Just installed the intel card again to see what happens, connects at 100mb........forced it to 1gb and now its working at 1gb.........and the internet is 40 down 20 up, but previously this will drop to near zero within hours, still cant understand these issues, any idea?
 
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Sounds like a bad cable. I know you said you tried a 2nd and even plugged it into a different machine and it worked, but I had the exact same issue with one of our servers in work. Forcing it to 1Gb worked, but then it dropped down to 100Mb. Replaced the cable it and worked fine.

Can you test it by running a long cable to the switch, or even moving the PC beside the switch? Just to fully rule out the cable as the problem.
 
Nymins said:
Sounds like a bad cable. I know you said you tried a 2nd and even plugged it into a different machine and it worked, but I had the exact same issue with one of our servers in work. Forcing it to 1Gb worked, but then it dropped down to 100Mb. Replaced the cable it and worked fine.

Can you test it by running a long cable to the switch, or even moving the PC beside the switch? Just to fully rule out the cable as the problem.
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Yeah the cable is 2m long and the switch is about 1m away, the cable is very high quality Cat 6, but using this cable in other computers makes it work at 1gb instantly no problem, I tried with a 2nd unmarked 'normal' cat cable , an old grey one and its the same on the main rig or testing with different computers.................anything but the main rig connects instantly at 1gb with either cable not a problem.............yet in main pc it all of a sudden starts to crumble
 
Just out of interest, what Anti-Virus software are you using? I've seen certain AV products murder the network card throughput

Try starting the machine in safe mode (with networking) & see if it still has the same issue
 
Faulty switch? Faulty port on the switch? Or could be software (virus, spyware) on the PC? i.e. you've ruled out the NIC and the cable, just trying to think of other things.

You mentioned "well known issues with Intel gigabit" -- what issues are those?

Usually when someone has this number of problems, there is something fundamentally wrong in the environment. Is your electricity supply faulty (e.g. full of spikes or interference)? Is your carpet synthetic and generates a much higher amount of static electricity than normal? Are you one of those people that tweaks every single Windows installation within an inch of its life with dozens of registry tweaks "to make it better/faster"?

These are just some things that spring to mind.

Here is what I would try:

Using a spare disk (disconnecting your current one), do a clean Windows build, no tweaks. Leave the built-in drivers if they come with Windows (i.e. don't install the Intel ones unless the NIC shows up as unrecognised). Does it still fault?
 
It may be worth trying a live Linux install to run some tests and see if you get the same under linux. That will rule in/out an OS issue.
 
Rebooted PC today and intel card is again running at 3mb, connecting with a wireless card now, will try all of the above suggestions tomorrow and get back to you.

Also and this might sound silly, I have an AC capable router, might just get a wireless AC adaptor and hopefully get near 1gb speeds?
 
Had an idea:

Is there a way of 'forcing' the computer to access the internet via the wireless adaptor yet make it access the local network via hard wired lan ? This way I could have fast internet and fast local network access which is important to me.
 
Combat squirrel said:
Is there a way of 'forcing' the computer to access the internet via the wireless adaptor yet make it access the local network via hard wired lan ? This way I could have fast internet and fast local network access which is important to me.
Click to expand...

There's not an easy way to set this up.. You could potentially set up a guest wifi network (restrict guests from connecting to the LAN & have a seperate IP subnet) & have your 802.11ac card connect to that & then configure your NIC with a static IP address (with no default gateway) for LAN side access

Personally focus on getting the NIC issue resolved as it'll will be the best way to access both LAN & WAN when working
 
Probably not your issue but I had a most frustrating one recently with poor network speeds where the capacitors had started going in both my main switch and the identical model backup which was a nightmare to troubleshoot as I'd made the assumption that atleast one of the switches would be fine :S

Bit strange both went at the same time when one was only really used for LAN parties, etc. and was fine 2 weeks before the problems started with the main one when it was last used, but both were from the same batch so I guess those caps must have naturally degraded over time.
 
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