torrent never starts when peers/seeds are not initially available

[GoogleCodeExporter]

What steps will reproduce the problem?
1. create custom torrent
2. try to download torrent on one client
3. later seed torrent on another client

What is the expected output? 
client that tries to download should begin to download the torrent when its 
being seed.  

What do you see instead?
Torrent download never starts. (waited 5 hours)

What version of the product are you using? On what operating system?
Using version 1.0.1 on Kubuntu 14.04

Please provide any additional information below.
I need to restart the torrent client to start download. This is bad for 
automated processes that use torrents with low number of peers/seeders.

Original issue reported on code.google.com by Pa.Trick...@gmail.com on 26 Aug 2014 at 4:53

[GoogleCodeExporter]

do you have any more details about what might be going wrong?

do you know if either the seed or the peer ever find each other?
do you have a tracker? is it working? or do you rely entirely on the DHT? is 
the DHT enabled?
if the peers find each other, does the downloader ever get unchoked? does it 
ever send a request?

Original comment by arvid.no...@gmail.com on 26 Aug 2014 at 5:59

[GoogleCodeExporter]

Hello, sorry for the delay.

Maybe it is because of my setup. I'm testing a distribution system locally on 
one PC. I have a tracker on a virtual machine from which i know is accessible. 
The torrents are private and DHT is disabled. I have 2 different torrent being 
seeded: one on the virtual machine, with which i have no problems. Another on 
the PC. And then some other torrent clients on the same PC who try to download 
the torrent.
The listening port range in libtorrent is set to (0,0), so the system selects 
the port.
I tried to check something out with wireshark, but the only thing i noted was 
that i never see the port where the torrent clients are listing too... but i 
now realized that i'm using an host only adapter plus NAT. Maybe this causes 
problems?  But it is strange that it sometimes works and other times not.
I will try a bridged adapter

Original comment by Pa.Trick...@gmail.com on 21 Sep 2014 at 12:56

[GoogleCodeExporter]

how long do you wait for the download to start? if you only have two peers, one 
of which is not connectable (behind a NAT without any forwarding), and the one 
behind NAT announces first, the download won't start until it announces the 
second time to find the seed (because the seed can't connect to it). Did you 
wait one full tracker announce interval? (that's typically 30 to 60 minutes).

If this is a common case for you, you may want to make the announce interval 
shorter for swarms with fewer than 2 peers on it.

Original comment by arvid.no...@gmail.com on 21 Sep 2014 at 8:09

[GoogleCodeExporter]

I only have the tracker behind a NAT. Then a seeder and a peer on the same PC.
Now i'm also seeding with uTorrent but it remains the same,  i let the peer run 
3h.
Also on uTorrent i can see that the tracker correctly reports 2 seeders and one 
peer.

Original comment by Pa.Trick...@gmail.com on 23 Sep 2014 at 10:14

[GoogleCodeExporter]

It seems it happens when i start the seeder a second time. Maybe it is caused 
how the tracker works?
If i restart the tracker then start the peer and afterwards the seeder it works 
after the second announce of the peer.

Original comment by Pa.Trick...@gmail.com on 23 Sep 2014 at 11:10