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I have a network of three Windows 7 computers, all with internet access, and all running wirelessly using a Netgear router and USB adapters. If the "bad" computer (and only the bad computer) is connected to the network, playing online games in the others is almost impossible (in any other tasks I don’t notice anything wrong). It causes massive amounts rubberbanding/warping, but at the same time, my ping is always 40-60.

I have closed every program and process to no avail (so it’s not related to torrents etc.), and also interchanged WiFi receivers, moved them, updated drivers... Also ran Trend Micro scans, and some other antivirus and nothing either. I have run Netalyzr many times, and sometimes when the problematic computer was on, it showed packet loss, but it wasn’t a really consistent trend.

I installed Wireshark, it showed there are a lot of "standard query" entries with the other computers names. Seems like packets are longer when the bad computer is connected. It fills up fast (full screen each 2-4 seconds) mostly with chunks of light blue and green/red. The light blue ones say ARP and Who has 192.168.1.xx? Tell 192.168.1.1.

This Wireshark IO graph shows byte length while online gaming and nothing else running (right side is with bad computer connected, the left side without):

Wireshark IO graph

Connecting it by ethernet makes the problem disappear, but that isn’t workable due to the distance and house layout.

I have no idea what to do next, and while the problem is only evident when gaming, it could be doing worse things without me noticing.

The internal ips:

  • 192.168.1.4
  • 192.168.1.3
  • 192.168.1.7 <-- this is the bad one

After disabling upnp in the router config, I ran wireshark another time (it shows that there is an abnormality), here is the packet lenght vs time graph while a game is running:

Wireshark IO graph

There were a lot of SSDP packets before I disabled upnp, and after disabling it many times less. This seems to have made the symptoms dissapear.

Some patterns I could see, which correspond to spikes in the graphs:

With only the good computer connected there are ARP queries each 10 seconds, looping through internal ips, most sent by the router as broadcasts, and some between the computers. This isnt different when the bad computer is connected.

If the bad computer is connected, there are groups of DCERPC, SMB and SMB2 packets in a pattern of 20-40-20-40... seconds. Most of these have sources and destinations that are ipv6 adresses (I suppose those of the computers). This doesnt happen if another good computer is connected, maybe its just some network function I enabled without noticing...

The graphs:

Wireshark IO graph

  • So what is exactly on the vertical axis? Is it a maximum wireless frame length? – pabouk Dec 21 '13 at 12:01
  • My guess is that radio on that box is causing actual radio interference. Possibly it's failing to "listen" before broadcasting, or otherwise not following Alohanet-style protocols. – Daniel R Hicks Dec 21 '13 at 13:44
  • Please provide the ip addresses of the router, wired and wireless connections in use, might be an addressing conflict. The arp messages you are seeing looks like they are coming from your router, this is normal behaviour. – Jake Dec 21 '13 at 14:53
  • Im sorry but I dont know much about networking. The vertical axis read byte lenght, I know nothing more. How can I get the ip adress and is it safe posting it publicly? Where can I see wired and wireless connections (as I said, they are only connected by a wireless network). – Keratosomo88 Dec 21 '13 at 18:44
  • No problem, nobody knows everything. Posting your home internal ip addresses is not an issue as the 192.168.x.x block is reserved for internal networks (alongside some other blocks) To get the addresses type ifconfig /all in a cmd.exe instance on all your win7 computers and add the results in your question. – Jake Dec 21 '13 at 20:10
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The cause of the trouble was having upnp activated and file sharing enabled (except in one computer, which threw me off). After disabling upnp the problem was gone, but anyways I disabled file sharing as I dont need it.

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The problem is clearly due to the wireless connection between the affected laptop and your router. The fact that it works OK for the other computers and when wired makes this clear.

I had a similar problem that was down to an incompatibility between my router and the particular wireless network card in the laptop. In this case I had to disable wireless-n mode at the router - though it would also work if you disabled it at the computer.

Now it wasn't the same router so it might not be exactly the same solution.

  • My computers dont have a network card, and swapping the USB wifi adapters from the "good" computers didnt solve it (installing drivers etc). – Keratosomo88 Dec 21 '13 at 19:40

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