LAN problem - can anyone help?

blackworx · Post by **blackworx** » Sun Jan 18, 2009 2:18 am

Hi folks,

Networking is definitely not my strong point. In fact I hate it; always have.

Ok, here's the story:

Home LAN: Wireless router with 3 x PCs (all wireless, all Windows, all with manually configured IP addresses)
PCs 1 & 2 (192.168.1.101 & 102) both run XP and both have shared folders which are frequently connected to by the other.
PC 3 (192.168.1.103) runs Vista, does not share any folders, nor does it connect to any shares on PCs 1 & 2. This PC belongs to our lodger, and I don't have access to it for testing.

Often, when PC 1 is on standby/off, PC 2's INTERNET speed slows to a crawl, and vice versa. When this happens, even accessing the router manager web interface from either of these machines takes > 15 seconds.

PC 3 never has any internet speed issues.

I just KNOW this is something to do with Windows file sharing on these machines, but I don't have a clue how to fix it or where to start looking. I did a fresh install of XP on PC 1 about two weeks ago to try and fix the problem, and it went away completely... until I started sharing folders again last night.

If anyone has any bright ideas I'd be very grateful to hear them as I hate being beaten by technology.

nick705 · Post by **nick705** » Sun Jan 18, 2009 5:21 am

I'm not a great networking enthusiast either, but maybe it's something to do with the way XP searches for scheduled tasks and resources by default on local network machines which share data - if it's constantly trying to get a response from the switched-off PC (and failing, obviously), it might keep the network tied up if your wireless LAN interfaces don't have enough bandwidth to cope.

I guess it could well be another problem entirely, but it might be worth applying the registry fixes here and see if it makes a difference...

andyb · Post by **andyb** » Sun Jan 18, 2009 5:23 am

Very strange problem, that I have not seen before.

Are your PC's password protected.?

Andy

blackworx · Post by **blackworx** » Sun Jan 18, 2009 6:08 am

Thanks for responses guys.

nick705 wrote:if it's constantly trying to get a response from the switched-off PC (and failing, obviously), it might keep the network tied up if your wireless LAN interfaces don't have enough bandwidth to cope.

That's what I'm thinking.

I guess it could well be another problem entirely, but it might be worth applying the registry fixes here and see if it makes a difference...

I will try them shortly, thanks

andyb wrote:Are your PC's password protected.?

One of them is (PC 1)

vertigo · Post by **vertigo** » Sun Jan 18, 2009 6:47 am

You can try using DHCP on your router, just to see if it make a difference. PC3 should be able to keep using its fixed IP.

angelkiller · Post by **angelkiller** » Sun Jan 18, 2009 6:56 am

This is just a guess....

Open any folder and go to Tools --> Folder Options --> View. Then uncheck "Automatically search for network folders and printers".

andyb · Post by **andyb** » Sun Jan 18, 2009 7:26 am

The easiest thing to do with windows sharing/network access is to have all PC's with the same username and password, this way all PC's instantly have access to all others because they will be logged in due to the fact that the username and password is the same as the other PC's.

This obviously isnt much good from the security standpoint, but I guess that wont be much of a problem for you. This isnt the cure for your problem, but I thought it was worth mentioning. I would expect that the problem is probably the Vista PC or something to do with your router.

You can test this really easily by simply pulling network cables. Simply turn all 3 PC's on, then turn one off, see that the slowness occurs, then pull the lan cable to the PC that has been turned off, and repeat until you have a better idea of whats going on.

Andy

xan_user · Post by **xan_user** » Sun Jan 18, 2009 7:48 am

Can you tell us more about the network?
Is dhcp turned off at router also?
have you tried turning using dhcp in router and pc 1&2?
what router?
any mapped drives/folders?
any remote desktop/programs or media sharing apps ?
does this happen when pc 1&2 are connected to router via cat5? or is the problem only wifi related?
default network workgroups?
default wireless ssid?
are there other wifi signals in the area?

Windows system error logs might tell you what process' are failing , if any..

blackworx · Post by **blackworx** » Sun Jan 18, 2009 11:01 am

I've been bashing away at this on and off for weeks and I think I've tried pretty much every combination of DHCP/manual/DHCP with IPs pre-assigned by MAC address, mapping drives to shares vs not mapping, default vs non-default workgroups, password vs no password.

DHCP is on at the router; the manual IP address thing was a kludge for a previous problem (like I say, networking not my forte). Not using any remote desktop/media sharing apps at all. Default workgroup, non-default SSID. At the moment I am seeing one other wireless network in the area, but there's usually more (block of flats).

I'm not helped by the router, which is a Netgear WNR854T. It's been flaky in the past and one was RMA'd after it locked up with the green ring of death common to the model. Plus it generally takes almost two minutes to apply any settings change, dramatically slowing down any experimentation with its config to the point where it just becomes frustrating. What's more, the lodger doesn't appreciate frequent interruptions to his constant P2P use/video streaming.

I'm also hobbled as far as testing goes, since I've only one spare CAT5 cable in the house which I keep for fallback use, and I'm unable to access the Vista PC, making it an unknown quantity.

Our lodger is moving out in two weeks, so I think it might be best if I just put up with it for now, then reset everything and rebuild the network from the ground up when he goes. If the problem doesn't go away when he does then I'll at least be able to test properly by then and resurrect this thread if necessary.

Thanks again for the help guys.

xan_user · Post by **xan_user** » Sun Jan 18, 2009 11:53 am

I would scan with netstumbler and see what channels the other wifi APs are on and choose one as far as possible from the others nearby.

When the second laptop is on it might be enough to over power the interference..?

(it will only disconnect your guest for about 90 seconds when changing this, and wont require any action on the pcs.)

Nothing more frustrating than a flaky router! Id bite the bullet and get a new one.(that runs dd-wrt)

sjoukew · Post by **sjoukew** » Mon Jan 19, 2009 12:55 pm

If somebody is uploading heavily on a shared connection, in case of an p2p client, all other users suffer greatly. When the p2p client is using all the bandwidth, there is (almost) no bandwidth left for other communication, such as web browsers asking for websites etc.
Also some cheap routers can be overwhelmed by p2p clients and just stop functioning quickly.

A quick way to diagnose is the ping command.
In an command prompt type ping [ipadres] for instance ping 192.168.1.1.
The result is a "test" of time it takes to send a ping message to 192.168.1.1 and the time it takes before the machine which executes ping to get the answer.
a response time < 1 ms is normal on a wired network.
10 ms is OK for an wireless connection.
based on an "idle" network.
Far greater numbers indicate a capacity issue somewhere, or heavy use of the network.
If you can ping your router and your other machines and the response times are good, the problem is not your internal network.
You can also ping a lot of websites (some do disable ping services)
To test your internet connection, you can always try to ping silentpcreview by typing "ping www.silentpcreview.com" (without the quotes ofcourse) if this is also quick, your internet connection is OK.
If it is slow, somehwere there is a problem, your connection to your router, your router, your internet connection, "the internet" or silentpcreview.

I wish you all the luck in finding your problem.

blackworx · Post by **blackworx** » Mon Jan 19, 2009 4:26 pm

Hi sjoukew, I tried pinging my router using -t switch and get some strange results...

I get ~1ms response mostly, with occasional >1000ms (every 25 pings approx).

When I disable MS client/file and printer sharing protocols, I get the same occasional >1000ms pings, but much less often (about every 50 pings).

In general, internet speed seems noticeably faster with MS client/file and printer shring protocols disabled on this machine.

sjoukew · Post by **sjoukew** » Sat Jan 24, 2009 5:23 am

When using a wireless network sometimes a packet gets delayed, due to several technical things. (I won't go into details here).
This looks normal and fast.
Have you tried your internet connection already?.

blackworx · Post by **blackworx** » Sun Jan 25, 2009 5:45 am

Hi sjoukew and cheers for the pm

.

Have you tried your internet connection already?

Not sure what you mean there. If you mean my actual internet connection, it seems to be working fine. When I attach a pc directly to the cable modem with cat5 there are no internet speed issues.

When the problem manifests itself and I get a very slow connection on PC1 or 2, it can always be relieved by disabling MS file and printer sharing protocol and MS client protocol on the wireless connection for the affected PC. Do you think this is likely to be related to our lodger's P2P use? i.e. Is there a possibility that he may be causing local network congestion which is being alleviated somewhat by me disabling these client/sharing protocols on my two machines?

thejamppa · Post by **thejamppa** » Sun Jan 25, 2009 8:07 am

What encycription do you use for your connection? WEP? WPA? Or WPA2? I storngly recomend that you firstly protect your connection with WPA2 and 64 character hexadecimal key, you get random generators all over internet.

That is starter. Wireless connection slowing down without parent reason usually mean someone is using your bandwith illegally if you do not have basic security options put for wireless connection.

I doubt that is the problem it its always good to check security things. The problem seems to be related synchronization. You probably have to define that you don't use IP filtering internal connections and you look the windows synchronization programs UDP and TDP ports and open them manually from router configuration.

What seems that someonething is blocking the PC2's access. Its either firewall or then you have some overlapping in Manual IP settings in which case you could try to put deifferent IP for Machine 2.

blackworx · Post by **blackworx** » Wed Feb 04, 2009 4:09 am

After our lodger left and the problem didn't go away, I did a bit of further digging and found that both affected machines were reporting warnings and errors with the browser service, a few issues including a lot of excess polling and repeated forced elections for the "browser master". After a bit of Googling I found a couple of registry tweaks to establish a permanent heirarchy to avoid the issue. Fingers crossed it seems to have solved the problem.

@ thejamppa: I'm using WPA2 with a fairly strong password (not quite 64 character hex, but good enough

) and there are plenty unsecured wifi networks popping up in the area, so any freeloaders would probably have much easier pickings to choose from.

sjoukew · Post by **sjoukew** » Wed Feb 04, 2009 12:15 pm

Good find!!. I hadn't thought of that one, although I have had similar issues a long time ago. I found a description on the microsoft website, describing the thing, for the interested readers.

vertigo · Post by **vertigo** » Wed Feb 04, 2009 4:13 pm

The thing with networks is that they work if everything is correct but if one thing is odd then it manifests errors all over the place. Over time you learn the symptoms and fixing them becomes easier, although this browser master thing is something I've never heard of.

One of the strange things about windows XP is that sometimes you configure the network settings and it doesn't work, and you run the configuration wizard which undoes the settings, redo the settings and then it works. The wizard has some unseen effects sometimes. Windows is really messed up like that.

I take it that it works now, but if it didn't, I was going to suggest running that "Network Setup Wizard" and then reconfiguring.