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Help! Need to stop one user's (ab)use of port 6881 on WLAN

Discussion in 'Cisco/Linksys Wireless Routers' started by crimsonchalk, Feb 13, 2006.

  1. crimsonchalk

    crimsonchalk Guest

    Hi there,

    I joined this forum because I am at the end of my tether - and there will be a bloodbath soon in my apartment if we cannot resolve this issue with our shared wireless connection, so if anyone can help I would really appreciate it.

    To explain the setup:

    There are 3 of us living together in an apartment: me, my boyfriend, and our new flatmate - let's call him 'Sam'.. We share a 2MB cable broadband connection via a WRT54G v2.2 router (firmware upgraded to most recent - October 2005). My boyfriend uses a PC with a wired connection into the router; myself and 'Sam' have wireless cards (me on my laptop, he on his PC) to pick up the connection.

    We have had this setup for months without any problem. Before our new flat mate moved in 4 weeks ago, we had a different guy living with us. He had a laptop with a wireless card, and for 6 months we all happily shared the connection. But ever since our new flat mate moved in it's been nothing but heartache - constant connection problems, having to reset the router at least 7 times - and of course plenty of arguments. The problem is basically this:

    My boyfriend installed Azureus (bittorrent) about 4 months ago, when the other guy lived with us. Occasionally, when he used it, myself and the other guy would notice a *slightly* slower connection with our wireless connection, so my boyfriend decided to only ever leave it downloading at night time when we were all in bed, or during the day when we were all at work, so as not to destroy the internet for everyone else. He would only use the Bittorrent maybe 3 times a week, so there was never any issue.

    4 weeks ago our new 'roomie' arrived. When we were telling him about the internet, and we mentioned how bittorrent slowed down the internet connection, as a way to 'hint' at some house rules.. he immediately started saying we would have to open port 6881 for faster downloads - as if he had found the solution to all our problems. I decided not to let him near the router password, because I was content that everything had been working OK beforehand with a simple system of respect for other people's rights, and since I'm not that savvy with routers, I didn't want him doing something sneaky to the settings to advantage himself.

    Anyway, ever since he moved in, we have had constant connection failures - and it always goes the same way:

    I will suddenly notice my internet connection is slow as hell. I will log into the router via the browser (which is also suddenly just as slow) and by the time I have loaded the logs, which show Sam's IP repeatedly making multiple connections to 6881, then the internet will finally die, and even when Sam finally turns off his PC, the connection is still gone for everyone, and the only way to get it back is to reset the router.

    The only slight improvement occurred last week, when we managed to sustain the connection for a whole week (whoopee) - purely because I added port 6881 in the Application & Gaming configuration (forget exactly which section) and added a 'low priority' to port 6881 and a high priority to port 80 (hoping that this would stop his downloading spoiling basic web browsing). I don't know if this made any difference, but I had no connection problems and Sam would occasionally complain about his 'slow' connection (although I could hear Yahoo Messenger buzzing away all night from his room, so obviously his connection wasn't dead - it was just his bit torrent that 'suffered'.. but a few days ago bam! Internet was bol***ed again.

    This guy seems to be a total net addict - never leaves the house, always having to download games or movies *every* *single* *night*. But I don't actually care about his hobbies - it's not my business - but when his greed for the bandwidth means i can't even open my gmail account or ftp-upload some tiny pictures to my website, then yes - his 'addictions' become my business.

    Because the ISP bill comes directly to me, I am in charge of the password to that router, and I refuse to give it to 'Sam', despite his frequent requests. This means that every time we have a router crash, it is me who has to reinstall the damn thing - and its every 3 days now. The whole situation is causing tension, even between me and my boyfriend who is threatening to throw the router through the window if the constant arguing continues.

    What is most strange us that problems ONLY occur when Sam is using port 6881 on his wireless PC. When my boyfriend uses the same program, there is absolutely no problem for anyone with the connection. Nor is there any problem when Sam uses a different P2P application - like Gnutella. I have been monitoring his port connections for a while now and even when he uses gnutella (port 6435 or something) there is no problem. It's always 6881 that causes connection problems. The problem is I cannot just 'ban' users from using port 6881 because my boyfriend uses Azureus too - the difference though is that when he uses it nobody else suffers a loss of service. That's what I can't understand - the only explanation it's because that my boyfriend uses a wired connection to the router ..?

    I am past the point of asking Sam to take steps to help the situation. I am sick of nagging him to configure his Bittorrent to limit uploads and downloads - he says he has done it, but after one day of a normal connection it's back to the same crap again, until eventually we have to reset the router again. He's gambling on my ignorance - hoping that I'm too dumb to realise I am being ripped off, and I've had enough of this.

    He probably thinks I am such an idiot - sitting her with the router password and in 4 weeks I haven't figuted out a way to curb is bandwidth theft. He pays one third of the internet bill, so kicking him off totally is a last restort - I would like to try simple good old fashioned network admin rules and restrictions.

    I have noted his MAC address and I am at the point now where I will unashamedly impose restrictions - I just need to know how to do this. Is there anyway I can ban just his PC from using port 6881? Or, as has been suggested, is there some way I can limit the upload or impose 'quotas' of bandwidth per machine in our network to be shared equally?

    Sorry to be a pain - but this problem is actually causing arguments between me and my boyfriend over how to handle it..! :-(

  2. NateHoy

    NateHoy Network Guru Member

    Actually, you can solve it a different way...

    1. Install aftermarket firmware on that router. That will solve the stability problems. For that model of router, I'd go with Tofu 13c. The native firmware has a lot of problems with heavy BitTorrenting.


    2. Configure QoS upstream properly on the router, so QoS will work.


    3. Set your BitTorrent buddy's MAC address at LOW and yours and your boyfriends to MEDIUM. Set Web surfing and other ports at MEDIUM.

    Once you do this, your BitTorrent buddy can use all the bandwidth he wants, but whenever you and your boyfriend want to use the connection, you get priority.

    If the actual bandwidth amounts become an issue, you can impose upstream limits, or simply artificially lower the upstream data rate in the router's QoS, which means there's less upstream to go around and you won't be pushing your upstream allocation so hard.

    EDIT: I'd also be concerned with WHAT he is Torrenting. If the Internet bill goes to you, so does the RIAA lawsuit if he is pirating music, etc. If he's doing TV shows or Open Source programs, that's OK, but if he does a lot of movies and/or music, you could be opening yourself to a lawsuit that could easily eat up several years' rent sharing.
  3. jgutz20

    jgutz20 Network Guru Member

    i used to have similar problems with azureus. Make sure he upgrades to the latest firmware. Also make him set the number of simultaneous connections down from unlimited, this can also overload when trying to connect to hundreds of peers for a single file. and last but not least make sure he doesnt have upload speed set too high. Im guessing when he closes azureus the problem is still there, and it will remain there until all those other connections that azureus makes time out. If you waited a few minutes i bet it would get back to normal.
  4. jgutz20

    jgutz20 Network Guru Member

    sorry, not firmware.... but updates the program to the latest version. Also, theres a little plugin for azureus called safepeer. It makes the program take a little longer to open up but keeps you safe.. :)

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