The short answer: if you are particularly concerned about anonymity, then yes, enable it AND use a VPN. But be aware some people may consider this leeching, because anonymous mode may compromise your ability to upload (and download) to some extent. But there are some circumstances in which this is entirely justified.

Public tracker scenario

For most people using public trackers, just a VPN without anonymous mode is fine and recommended, and gives you the maximum speeds in this scenario, while giving you an adequate level of protection from your ISP (if configured correctly). If you do enable anonymous mode, then you'll likely find your upload/download speeds are slower, mainly because DHT & uPnP are typically disabled. And anonymous mode without a VPN is NOT recommended.

WARNING: anonymous mode doesn't provide strong privacy guarantees on its own. If you are concerned about legal authorities and copyright trouble, for example, consider using a VPN instead (or in addition to it).

Private tracker scenario

If you are using private trackers then you would usually not be using a VPN or anonymous mode because many of them explicitly ban such things so they can track your download/upload ratios server-side against your IP address to ensure you are following their policies. While some private trackers allow exceptions to this (e.g., you may be able to get a dedicated VPN IP address whitelisted for your account after signup), many don't.

I'm not claiming to be any great expert on this topic, and so this is just my general-level understanding. If anyone wants to contribute any useful expert info or to correct anything I may have wrong here, please feel free to comment.

[–] weirdo_from_space@sh.itjust.works 8 points 7 months ago (1 children)

In my experience most entry level private trackers allow using VPNs. I don't know about anonymous mode, I have never heard about it before.

[–] drunkensailor@lemmy.dbzer0.com 1 points 7 months ago (1 children)

prety sure MAM dont allow vpn

[–] weirdo_from_space@sh.itjust.works 2 points 7 months ago

I didn't take the MAM interview so I can't speak on that front. All of my stuff is from OpenSignups.

[–] slighting4295@lemmy.dbzer0.com 6 points 7 months ago* (last edited 7 months ago) (1 children)

I'm quoting from https://www.reddit.com/r/Piracy/comments/cpzix0/qbittorrent_anonymous_mode_useful_with_v_p_n/

AtlanticJack Wednesday, August 14, 2019 at 4:11:29 AM EDT who wrote about the topic:

That's not how I understand it. In older versions it does disable LPD DHT etc but in versions since v3.3.0 it disables the client's fingerprint, creates an empty string for the user agent and doesn't expose other identifying information directly yo the public such as IP, port etc.

The LPD DHT etc is now covered in the proxy section by "Disable connections not supported by proxies".

I use anonymous mode and also disable connections not supported by proxies, still seem to get plenty of seeds and peers via DHT and PeX though.

I know that copyright trolls have used modified versions of torrent clients to join swarms and log the participants IP. Well they wouldn't get my IP because I'm using a proxy or vpn but they also wouldn't get any fingerprints or user agent info from my qBittorrent client if I'm using Anonymous Mode.

Xen0Man Tuesday, December 3, 2019 at 6:31:21 PM EST in response to somebody stating VPN is enough:

Mmh not really... Anonymous mode is meant to be used together with VPNs. It blocks libtorrent advertising facts about you. For example, client's fingerprint (in peer ID) or user-agent.

You should never disable anonymous mode, unless you want to connect to some private trackers that uses the peer ID and user agent to identify white-listed clients.

[–] Flatworm7591@lemmy.dbzer0.com 3 points 7 months ago

Okay, that's useful additional info, I figured I was probably a bit out of date on the technical details :p

[–] slighting4295@lemmy.dbzer0.com 2 points 7 months ago* (last edited 7 months ago) (1 children)

you’ll likely find your upload/download speeds are slower, mainly because DHT & uPnP are typically disabled

If anonymous mode was disabled for a public tracker, are having DHT & uPnP still enabled dangerous? And what if qbittorent is bound to a network interface (the VPN), wouldn't all qbittorent data still have to passthrough the VPN regardless?

I kind of get that uPnP can open up ports without user intervention, but I've seen VPNs offer specific ports during connection so I'm not to worried about that.

[–] Flatworm7591@lemmy.dbzer0.com 1 points 7 months ago

I think it's generally recommended if you are security conscious to manually forward ports rather than allow uPnP to be enabled on your router. There's been cases where IoT devices or apps can open sensitive ports to your network without your knowledge. And the uPnP protocol itself was found to be flawed a few years ago: https://arstechnica.com/information-technology/2020/06/upnp-flaw-exposes-millions-of-network-devices-to-attacks-over-the-internet/

Çadırcı reported his findings to the Open Connectivity Foundation, which maintains the UPnP protocol, and the foundation has updated the underlying specification to fix the flaw. Users can check with developers and manufacturers to find out if or when a patch will be available. A significant percentage of IoT devices never receive updates from manufacturers, which means the vulnerability will live on for some time to come.

But you know, it depends on your risk profile. For most people, it's probably fine. Depends how paranoid you want to get.

Binding your VPN connection to qbittorrent is a good idea, for sure, if you use a VPN. I usually keep DHT enabled with a bound VPN connection and a manually forwarded port using Proton VPN. I'm going to try out anonymous mode to see if it affects speeds any, since it looks like it doesn't impact uploads or connections any more. That's a bonus :)

[–] antlion@lemmy.dbzer0.com 1 points 7 months ago

I was just wondering if Anonymous mode could be responsible for the false hits on iknowwhatyoudownload.com from my static IP