Port 8090 and 8091

[teddyrogers]

Is there any particular reason why Tribler uses ports 8090 (UDPIPv4) and 8091 (UDPIPv6)?

Would there be any advantages or disadvantages using alternative private ports. Examples are; IANA assigned ports like 1027 and 3784 or unofficial Bittorrent ports; 6881-6887, 6889–6900, 6901–6968?

[qstokkink]

This is mostly historical. At some point (well over a decade ago), our Tribler ancestors decided on these ports, because nobody else seemed to use them. I think back in 2006 Tribler still used to use a port in the 50000's range (because it was also free).

The one downside to lower port ranges, is that there is more competition. So, a higher chance of not getting the port you want.

[teddyrogers]

@qstokkink would you consider changing the default ports in Tribler to zero (0) and letting the operating system decide? I can raise an issue to track as an enhancement.

[qstokkink]

As the default, I see no reason to change this. We already have port re-allocation if binding fails and if you really insist on it being set to port 0, you can change your configuration file.

[teddyrogers]

@qstokkink can these ports be made accessible to configure in, "Settings -> Connection", as it seems everything else is captured except for these ports?

[qstokkink]

Technically, yes. Practically, it wouldn't really make sense for normal users to change the port and this would only clutter our interface. I consider this part of the "just because you can, doesn't mean you should"-types of features.

By default, our settings are compatible with "normal" firewall setups. It would only make sense to set these ports if whomever is setting them can guarantee that the port is free anyway. Otherwise, the setting is ignored and a different port is chosen. This is really only meant for advanced usage, such as people running with strict sandboxing rules (like Docker or Flatpak setups). Essentially, anyone with a legitimate use for this knows how to edit the configuration.json file.