FC2 BitTorrent URL's

[Jim Cornette]

Jack Bowling wrote:

>On Tue, May 18, 2004 at 02:21:12PM +1000, Scott Burns wrote:
>  
>
>>Paul D. Brown wrote:
>>
>>    
>>
>>>Quoting from the bittorrent FAQ at http://btfaq.com/serve/cache/25.html
>>>(no doubt elsewhere as well):
>>>Prior to version 3.2, BitTorrent by default uses ports in the range of
>>>6881-6889. As of 3.2 and later, the range has been extended to
>>>6881-6999. (These are all TCP ports, BitTorrent does not use UDP.) The
>>>client starts with the lowest port in the range and sequentially tries
>>>higher ports until it can find one to which it can bind. This means that
>>>the first client you open will bind to 6881, the next to 6882, etc.
>>>Therefore, you only really need to open as many ports as simultaneous
>>>BitTorrent clients you would ever have open. For most people it's
>>>sufficient to open 6881-6889.
>>>
>>>Paul
>>>
>>>
>>>
>>>
>>>      
>>>
>>Let's see if I understand: I download one file by bt, and other people 
>>can connect to 6881 on my machine to download from me.  I start a second 
>>simultaneous bt download of another file.  Others can now connect to me 
>>on port 6882 to download the second file from me?
>>
>>This strikes me as slightly loopy given http seems to be able to serve 
>>many files using just one open port...
>>    
>>
>
>Scott - As an exercise in how quickly BitTorrent works its magic, start up
>a BT download and then fire up iptstate (comes as part of FC2 Golden...not
>sure about FC2T3 and earlier). Becoming part of the swarm is virtually
>instantaneous. You will also see that the connections are persistent.
>  
>
I'm running FC1 and iptstate does not seem to be present. I ran netstat and got the following output.

Active Internet connections (w/o servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State
tcp        0   9800 192.168.1.100:36342     user1.com:6881 ESTABLISHED
tcp        0  37128 192.168.1.100:36458     user2.com:6881 ESTABLISHED
tcp        0  15928 192.168.1.100:36384     user3.com:6881 ESTABLISHED
tcp        0   6883 192.168.1.100:33648     user4.com:6886 ESTABLISHED
tcp        0  14618 192.168.1.100:34383     user5.com:6881 FIN_WAIT1
tcp        0   9763 192.168.1.100:33649     user6.com:6882 ESTABLISHED
tcp        0  60242 192.168.1.100:33356     user7.com:6881 ESTABLISHED
tcp        0  15928 192.168.1.100:33784     user8.com:6881 ESTABLISHED
tcp        0  33304 192.168.1.100:36287     user9.com:6881 ESTABLISHED
tcp        0  21720 192.168.1.100:36450     user10.com:6881 ESTABLISHED
tcp        0  70000 192.168.1.100:36391     user11.com:6881 ESTABLISHED
tcp        0      0 192.168.1.100:36079     user12.com:6881 ESTABLISHED


I don't understand much of the output. It looks like all users except for user4 and for user6 are on the same port. I assume they are all receiving the same bits.
 If I'm able to guess the information on my local address, I check (the torrent actually) their progress using individual ports on my end.
.....
 I just checked the output again and there are 11 users, all but the Send-Q numbers are the same. User7 dropped out of the race, 33356 is no longer in the local address output.

Pretty interesting, but confusing!

netstat |grep tcp


Jim