Is this mode needed if you’re using a VPN to hide your IP address? The page states only the following:
If you’re using VPN, proxy or I2P, you probably want to enable Anonymous Mode.
What I would like to know is why the developer statement is true? And does it affect download/seeding speeds?
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.
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.
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:
Xen0Man Tuesday, December 3, 2019 at 6:31:21 PM EST in response to somebody stating VPN is enough:
Okay, that’s useful additional info, I figured I was probably a bit out of date on the technical details :p
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.
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/
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 :)