Call for volunteers: IPv6 DHT

Discussion of Transmission that doesn't fit in the other categories
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jch
Posts: 175
Joined: Wed May 13, 2009 12:08 am

Call for volunteers: IPv6 DHT

Post by jch »

Hi,

We (The8475, titer and myself) are currently testing the new IPv6 DHT. If you have IPv6 connectivity, please have a look at

http://forum.bittorrent.org/viewtopic.php?id=134

and see whether you can help.

If you don't have IPv6 connectivity yet, get it.

I have a ready implementation for Transmission, I'll attach it under #2576 soon (the version dated 17 September is buggy).

--Juliusz
cherubin
Posts: 6
Joined: Mon Jun 02, 2008 9:23 pm

Re: Call for volunteers: IPv6 DHT

Post by cherubin »

IPv6 Bootstraping with Transmission 1.76+ svn9559 on a Ubuntu miredo 1.1.3 machine seems to work good.
jch
Posts: 175
Joined: Wed May 13, 2009 12:08 am

Re: Call for volunteers: IPv6 DHT

Post by jch »

Yep, it looks like the IPv6 DHT has bootstrapped pretty nicely. There are about 200 nodes in the DHT, most of which are the Azureus "mldht" plugin.

--Juliusz
jch
Posts: 175
Joined: Wed May 13, 2009 12:08 am

Re: Call for volunteers: IPv6 DHT

Post by jch »

x190 wrote:jch, or anyone. How to add ipv6 nodes from dht.wifi.pps.jussieu.fr port 6881 to dht.dat?
It will happen automatically -- Transmission will automatically bootstrap from dht.transmissionbt.com (a large subset of dht.wifi.pps.jussieu.fr) if its regular bootstrap fails. For a manual boostrap, see http://trac.transmissionbt.com/ticket/2280#comment:9 .

But that should not be necessary -- it looks to me that you have some issues with IPv6 routing. Perhaps a firewall in the way?

--Juliusz
jch
Posts: 175
Joined: Wed May 13, 2009 12:08 am

Re: Call for volunteers: IPv6 DHT

Post by jch »

It really looks to me like you have no IPv6 connectivity at all -- your 6to4 tunnel is not working. (The IPv6 nodes you're seeing are just addresses of IPv6 nodes that your node learnt from IPv4 nodes.)

What do the following say?

Code: Select all

ping6 -n -c 10 huponomos.wifi.pps.jussieu.fr
ping6 -n -c 10 www.ietf.org
traceroute6 -n www.ietf.org
tracepath6 -n www.ietf.org
jch
Posts: 175
Joined: Wed May 13, 2009 12:08 am

Re: Call for volunteers: IPv6 DHT

Post by jch »

Actually, it looks like a firewall problem on your local host -- the traceroute result indicates that your packets never reach your router. Since I don't run Mac OS myself, I cannot help you any further -- I suggest you ask on a Mac-specific forum somewhere.

Sorry for that,

--Juliusz
jch
Posts: 175
Joined: Wed May 13, 2009 12:08 am

Re: Call for volunteers: IPv6 DHT

Post by jch »

Glad to hear it works for you. (You do realise that by running a Teredo daemon on your Mac, you're making Steve Jobs cry?)
IPv6 DHT has 72 nodes and announces complete okay.
Same here. That means that there are roughly 4000 nodes in the IPv6 DHT, as opposed to tens of millions in the IPv4 one. (As long as there are enough IPv4 µTorrent peers, though, you'll get your fix of IPv6 peers from PEX.)
I would like to know if IPv6 peer numbers will be shown separately, both in Message Log and Inspector.
Check the address column in the inspector.

--Juliusz
jch
Posts: 175
Joined: Wed May 13, 2009 12:08 am

Re: Call for volunteers: IPv6 DHT

Post by jch »

x190 wrote:I feel like a proud father. My first IPv6 peer!!!
Congratulations! What you're seeing is an address generated by the Windows implementation of 6to4 (which duplicates the IPv4 address at both bit 16 and bit 96).
I see I'm blocking quite a few incoming IPv6 connection attempts,
Why not open just the Transmission port? It shouldn't be any more risky than just running Transmission in the first place.

--Juliusz
jch
Posts: 175
Joined: Wed May 13, 2009 12:08 am

Re: Call for volunteers: IPv6 DHT

Post by jch »

x190 wrote:It seems Transmission makes almost no attempt to make connections to peers it gets from DHT. e.g. Learned 69 peers from DHT, but I'm only connected to the grand total of 1.
There are multiple factors at play here. First, Transmission deliberately prefers peers obtained from trackers to peers obtained from the DHT -- an arbitrary choice, but one that makes sense considering that the user can control the set of trackers, but not the set of DHT nodes. Second, the DHT is much slower than either trackers or PEX, so by the time Transmission has obtained any peers from the DHT, it usually already has plenty of tracker and PEX peers (note that if a peer can be obtained both from the tracker and the DHT, it will be marked as whatever place it was first learnt about).

Finally, the DHT has no mechanism to discard unreachable hosts. According to some estimates, up to 2/3 of DHT peers are unreachable.

I'd suggest the following test: choose a torrent, and in its inspector pane, manually remove all of the trackers. Then stop transmission, remove this particular torrent's resume file, and restart transmission. You'll see how fast the torrent is able to get up to speed from the DHT and PEX only.
Can you [...] tell me if Transmission can use it's loaded blocklists against IPv6 addresses.
A quick glance at the code in r10539 seems to indicate it's IPv4-only. I could be wrong, I've only looked in the most obvious place.

I'm not going to implement IPv6 support in the blacklist, since (1) I happen to think that manually maintained blocklists are a silly idea, and (2) in the rare cases when I do want to blacklist a range, I prefer to do it at the lowest layer possible -- in a host specific firewall, or, better yet, in my router's firewall.

(Before anyone accuses me of being a "rotten apple" again -- the above does not mean I'm opposed to the feature, just that *I* am not going to implement it. I'll be happy to review patches if somebody else writes them.

--Juliusz
jch
Posts: 175
Joined: Wed May 13, 2009 12:08 am

Re: Call for volunteers: IPv6 DHT

Post by jch »

x190 wrote:Was dht.transmissionbt.com down on the IPv6 side?
Something has changed on the server side -- dht.transmissionbt.com used to be a pool of two addresses, it is now just a single address. I'll try to get it sorted out.

Temporary outages like that are not too worrying, though. Transmission implements four different techniques for bootstrapping a DHT, and using dht.transmissionbt.com is just a last-resort technique for when the DHT hasn't reached critical mass yet (and the IPv6 DHT hasn't).

(FWIW, Skype had their DHT collapse a couple of years ago. It took three days for the DHT to recover, three days during which every node was hitting the Skype servers for bootstrapping.)

--jch
jch
Posts: 175
Joined: Wed May 13, 2009 12:08 am

Re: Call for volunteers: IPv6 DHT

Post by jch »

x190 wrote:Allw- 254.245.190.156:51413 -> 180.97.107.22:49718 udp6 'Transmission (584)
Something's definitely fishy -- there shouldn't be any traffic from class E addresses. I suspect that it's simply the logging software that's buggy, and mis-printing IPv6 addresses.
Can't seem to block these addresses.
X190, if you think that by manually blocking addresses you're increasing your anonymity, you're mistaken. BitTorrent is intrinsically a noisy protocol -- please assume that your wife, your neighbour and your friendly local law enforcement agency know exactly what it is that you are downloading.
jch
Posts: 175
Joined: Wed May 13, 2009 12:08 am

Re: Call for volunteers: IPv6 DHT

Post by jch »

Guess the Chinese have their own way of doing things and perhaps aren't very concerned about our protocols.
Nonsense. There is no evidence whatsoever of China not obeying Internet standards (except for the Great Firewall playing weird tricks with DNS). I actually trust the Chinese to do things right much more than Verizon.

What your log shows is packets exchanged between China and Class E space. First, there is no such thing as Class E -- a packet to Class E space should be shot on sight by any half-competent ISP. Second, even if your ISP did let such packets through, there's no reason why they should go through your machine.

I'm fairly confident that your log is incorrect. Please file a bug with whoever produced whatever software you're using for logging.

--jch
jch
Posts: 175
Joined: Wed May 13, 2009 12:08 am

Re: Call for volunteers: IPv6 DHT

Post by jch »

x190 wrote:Would you say anyone with a bit of smarts can connect to T via my Teredo tunnel and DHT and then use Firefox to phone home?
I certainly wouldn't. Please stop reading the marketing materials of the so-called "security experts".
x190 wrote:Is there a logical explanation for this observed behavior?
That a little knowledge is a dangerous thing? Please stop reading the marketing materials of the so-called "security experts".

BitTorrent is a fundamentally noisy protocol, and no amount of cargo-cult behaviour will change that. Using Teredo doesn't make things any worse than they already are -- please stop reading the marketing materials of the so-called "security experts".

The only advice I can give -- if you really care about your privacy, do not use BitTorrent. Anyone who tells you he can mitigate the privacy issues in BitTorrent is lying, please stop reading the marketing materials of the so-called "security experts".

--jch
jch
Posts: 175
Joined: Wed May 13, 2009 12:08 am

Re: Call for volunteers: IPv6 DHT

Post by jch »

X,

I'm not sure that you are not listening to what I'm saying.

Your logs don't make sense. Please discard whatever software is producing these logs, and do not propagate any further FUD based on these logs.
using firefox-bin to call home
If your computer is "calling home" using firefox-bin, this has nothing to do with your use of Teredo.
hooking up with local port 0
Port 0 is reserved. No operating system known to me will allow an application to bind to port 0.

X, I suggest we stop this discussion. None of your observations make any sense whatsoever.

--jch
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