BitTorrent on a Mac (Specifically, Transmission)

[Ledgem]

After a bit of looking around, I've gone with Transmission as my client of choice. It's not as good as uTorrent, but I'd rather have a decent client that I can use without having to start up Parallels (and Windows). If anyone has any other recommendations, please give them. I'm avoiding Azureus as it is rather system-intensive, but it may be the only client on the Mac that has features rivaling those of uTorrent.

My specific issue with Transmission is this: in the message log, I noticed about five "ERR Could not connect socket (Can't assign requested address)" messages. The client performance doesn't seem adversely effected, as far as I can tell, but I was wondering about those messages.

I'm running behind a router that has UPnP enabled, and Transmission seems to be set to use UPnP. Its little indicator states that my incoming TCP port is stealthed (with a red dot; I presume this is bad), but that "Port is successfully mapped" (with a green dot). Below that, it says that NAT transversal uses either NAT-PMP or UPnP.

In the Mac firewall, I only have "Network time" allowed, and "Stealth mode" is enabled (UDP traffic is not being blocked, however). I can probably troubleshoot the stealthed port issue myself, but I figured I'd ask anyway: is this something that I need to forward on the router, or on the Mac firewall? Are there any ports besides the one listed in Transmission that I should create a rule for?

Edit Created a rule in the firewall to allow the port, and it removed the "port is stealth" error. It wasn't anything on the firewall end. Feedback about which client to use would be appreciated, though. I don't want to unknowingly be using a "selfish"/harmful BT client.

[WanderingKnight]

Seriously speaking, I've been an Azureus user for as long as I can remember, and I never experienced a noticeable system hog on me. Even while it is Java, and it certainly shows a kinda whooping use of RAM (60 MB), I never actually felt hit by it. I don't know how does OS X handle it, though, and granted, I never took the time to download uTorrent and test it around. But, even with my modest PC specs, I'd be daring to tag the system-intensiveness of Azureus as heavily influenced by myth. I've gamed around with 3D applications back in my Windows XP days while having Azureus open, and even then, with my humble AMD Athlon XP 1.5 GHz, my 512 MB of RAM and my old FX 5200 128 MB, and I certainly didn't feel any downsides to it.

Maybe my experience is too limited, or I should have really checked out uTorrent back then (it's useless now that I'm on Linux ), but seriously speaking, I never felt any true downsides to it.

[Kyuusai]

I enjoy Azureus, but on OS X it is, indeed, a system hog. Not to mention that after running for a period of time (especially, for some reason, if I leave the computer locked at the login window), it memory and CPU consumption grows to crippling levels. I resign myself to restarting it occasionally. Since I don't need the advanced features, perhaps I should use Transmission... Oh, if only it worked as well as it did on other OSes.

As for the firwall issue:
If Transmission is making the UPnP connection, you shouldn't have to forward any ports on the firewall, but you WILL need to open the port up on the OS X firewall. Stealth mode shouldn't make a difference, though, as it should only affect ports the firewall is blocking.

If you're behind a hardware firewall, though... Aren't you being extra paranoid running the local firewall?

[Ledgem]

Originally Posted by Kyuusai

If you're behind a hardware firewall, though... Aren't you being extra paranoid running the local firewall?

Never! I'm an ex-Windows user (still use it under Parallels); I can never have enough security!

[onitake]

there are plenty of other clients for mac os x.
i can particularly recommend those that use libtorrent, and from those, BitSlug and BitRocket.
bitslug (http://bitslug.sf.net/) was written be myself and still has a long way to go, but does its duty nicely and without unneccessary and resource-eating features like azureus
bitrocket (http://www.bitrocket.org/) looks much nicer and is more maintained, but offers not many more functions than bitslug atm
have a look at http://www.rasterbar.com/products/li.../projects.html for more clients that use libtorrent.

[Ledgem]

I'm recycling this thread somewhat, although the issue is new.

I recently tried using Transmission under a new netwok setup, and now with OS X 10.5 (note that the original post that started the thread was made while I was under 10.4). It consistently said that the port it listened on was closed. I tried everything - I ensured that UPnP was enabled on my router and on the modem-router it connects to; I disabled UPnP listening and manually forwarded the port; I did both of those with the Mac OS X firewall set to "allow all" - nothing changed it, and my performance was pretty horrific. I opened Windows XP in a virtual machine, set its network type to "bridged" (it takes on its own IP from the router as though it were a separate physical machine), and the torrent is currently blasting away at full speed, with µTorrent stating that the network connection is all good. No ports are being forwarded for µTorrent - UPnP is functioning as it should.

Does anyone have any ideas what to do? In theory, a final test to do would be to set the virtual machine to run its network through the Mac OS X network (taking an IP via NAT), but I'm not sure what that would accomplish - it seems that the issue is either on the part of Transmission, or on the part of the operating system. The next logical step would be to test with a different BitTorrent client, but I don't particularly care to go with another one. What I'd like to know is, has anyone heard of this issue before, and does anyone have any ideas for how to solve it? Mac OS X 10.5 made some changes to the firewall. In my opinion they removed a number of configuration options. I wonder if it has something to do with that, although again, I noted no difference when setting the firewall to "allow all."

Any help or advice is appreciated

[SeijiSensei]

Is it possible to simply turn off the firewall entirely instead of choosing "allow all?" I don't know anything about OS X other than it has *nix roots. If so, how does it determine what services to start at boot? On *nix, there are usually start up scripts in /etc/rc.d. If there's no setting to disable the firewall entirely, maybe you can find the startup script that runs and disable that.

[Ledgem]

The options for the firewall are: allow all, allow only essential services (previously this was misleadingly called "block all"); and set access for specific services and applications. I use the last option, which lists programs that have tried to access the internet and gives the option of either "allow incoming connections" or "block incoming connections." Nice and simple, I suppose, but it's a pretty anemic firewall.

The advanced options deal with logging and also allow for "stealth mode" to be turned on or off. I keep it on.

Since I wasn't able to turn up a multitude of posts related to mine on Google I presume this isn't a Mac OS X-wide issue. I may try taking it to the Transmission forums to see if it's something on their end. I guess I'll just keep using µTorrent through Windows XP for any serious torrenting that needs to be done, for now.

[Epyon9283]

To verify that the OS X firewall is indeed allowing everything, open up a terminal and type this command:

sudo ipfw list

You should see this:

65535 allow ip from any to any

10.5 also has some funky per-application firewall but if you see the above it should be off AFAIK.

My router is a POS and doesn't deal with UPnP all that well so I manually forward a port of my choosing. I set up both Transmission and Azureus to use that port. Never ran into any issues.

I would use some firewall testing site like http://www.grc.com/default.htm (look for shields up) to test to see if the specific forwarded port is indeed open. Make sure Transmission is running while you do this. You can't always trust the built in thing in the app to tell you if the port is open.

Transmission has other more serious issues on OS X like causing machine hangs. Generally happens to me when using speed limit mode. Something about the network buffers filling and OS X taking a dump.

[gunshottrigun]

I've found that Transmission runs best, at least until uTorrent is out of beta. Transmission has its fair share of problems though. At times it is a memory hog, freezes everything, and lacks some features.

[chikorita157]

I have run Transmission with a Buffalo Wireless 54g router with DD-WRT firmware and I haven't had any problem with download speeds and upload speeds. A software firewall is unnecessary when you are behind a router since most of the time, hackers won't be able to access your computer unless ports are open. I don't even bother with the default Mac OS X firewall and just use Little Snitch as my software firewall and Bittorrent works perfectly fine.

If your router is compatible, I recommend installing DD-WRT onto your router... It will solve most of the Bittorrent problems and they have helpful features like monitoring your bandwidth usage and other stuff.

[sk3]

i have a WRT54GL running utorrent on windows and transmission when needed on my mac without any problems. i usually use transmission (when out of home on my laptop) in a friends house which has the same router as myself and runs beautifully.

Oh, and both routers run Tomato firmware, an alternative firmware like DD-WRT. No problems here, as far as i noticed

[Prinny]

I use Transmission myself and I think it's probably the best bittorrent client out there for the Macintosh. (I used Azureus and I found it really slows down my comp. and uTorrent really wasn't for me.)