BitTorrent: can't upload after download is done!

[bbernardini]

Well, mostly. :) It seems as though I am unable to upload data amounts of any significance after I am finished downloading. During downloading, no problem. But when I am seeding, I seem to be unable to connect to any peers. This is happening with torrents from several sites, but seems most obvious with one in particular.

Here's as many details as I can think of:

-Running 2.5.0.0 on a Mac running 10.4.8.

-Mac firewall is off.

-Linksys router BEFSR41, with a variety of ports in different ranges forwarded to the Mac. Azureus sees all of these as being forwarded, and the website with the most problems does NOT see me as firewalled.

-Motorola SB5120 Modem

-NAT OK

-Super-seeding off

-Lazy bitfield on

-Transport encryption on

-UpNp disabled

-Many variations on allowed number of users per torrent and globally have been tried.

-Upload speed capped at 40 kB/s.

-Problem seems to happen on torrents with both many and few seeds. For example, here's what my list looks like:

0 (48) 0 (6)
0 (21) 0 (1)
0 (1259) 0 (5)
0 (545) 1 (53)
0 (22) 1 (1)

The first four are from the same site, the last is from a different one. Despite one peer being connected on the fourth one, the last one is the only one that is getting any upload activity at all.

-Connecting the modem directly to the computer results in a complete loss of Internet connection. When connected in this way, I am also unable to reach the modem through http://192.168.100.1/. When connected through the router, I can connect to the modem for a split second, after which I get a "The connection to the server was reset while the page was loading" error.

-Tried uninstalling 2.5.0.0 and reinstalling 2.4.0.2. Same problem.

Again, this only happens with files I am seeding after download. One of the ones in the list above had a ratio of 99.3% when the download was complete, so I know uploading is possible. I'm at a complete loss as to how to solve this problem. Any assistance would be greatly appreciated. Thanks!

[htuttle]

1. I've had the same problem when others were 'torrenting' on my network

Also, and this might have something to do with it, we use a Linksys router at work and have to reboot it fairly often (we have a script do it now).

What happens is that the router only has about 500 'NAT slots' that remember the mapping between addresses inside the network and those outside the network. If you connect to a great many host/port combinations in a short period of time, ie., shorter than the default timeout for those mappings, you will find you can't connect to the outside network anymore. Oddly enough, when it's in this state, I've had no trouble connecting to the inside (via a forwarded port) from the outside -- it's connecting to the outside from inside that becomes a problem. Rebooting the router fixes things.

I don't know that much about the bittorrent protocol, but I'd imagine that their distributed sharing system would indeed create a large number of host/port mappings in the router in a short period of time. Maybe your router just doesn't have enough RAM to handle it. Most of them don't have very much at all.

If you can turn NAT off (and if your ISP won't freak out if you do that), and make your router act more like a bridge, that might fix it. However, I wouldn't put a lot of money on being able to get your router to do that, and also be able to get a DHCP address from your ISP without your router. It's the only idea I have about fixing this, though.

[bullimiami]

2. i use azureus. works without a problem. i like it a lot better than bittorrent

or tomato or any of the myriad others ive used.

i have a very similar setup.

[remfan]

3. Only thing I can think of that you didn't mention...

but that you may have already done - I had to give each computer on my little network its own IP address and then set that number in the router before it worked properly - if you've done that then I don't know what else to suggest. FWIW, I'm running 2 Macs and a Windows laptop with a Linksys router and DSL modem with different torrent clients on each machine. The client should be uploading as you're downloading, too - is that not happening?

[stepnw1f]

4. I Prefer Azureus (nt)