Document port binds and what they are used for

[jellyfin-archive]

Document port binds and what they are used for

[sparky8251]

1900/udp (SSDP) is another. Its for service discovery and I assume it's for the autodiscovery on your LAN as mentioned in JF #402 but I'll want confirmation before documenting it as such,

[sparky8251]

Seems that it also binds two udp ports that aren't listeners. Unsure if they are required as they are in fact random. Should investigate and remove the binds if they are useless and if they have uses, document them.

[joshuaboniface]

49251/udp

This is an ephemeral port, and changes to a random one at startup. Example netstat output:

tcp6       0      0 :::8920                 :::*                    LISTEN      21520/jellyfin
tcp6       0      0 :::8096                 :::*                    LISTEN      21520/jellyfin
udp        0      0 0.0.0.0:43418           0.0.0.0:*                           21520/jellyfin
udp        0      0 0.0.0.0:7359            0.0.0.0:*                           21520/jellyfin
udp        0      0 0.0.0.0:1900            0.0.0.0:*                           21520/jellyfin

UDP doesn't "listen" since it's connectionless ;-)

[sparky8251]

Ah! So they could very well be listening but there's no way of telling without digging into the code. All the more reason to investigate and find out.

[sparky8251]

7359/udp seems to be part of the DLNA/Chromecast implementation.

In the server implementations, you can see it bind that udp port and this related code:

AddMessageResponder("who is EmbyServer?", true, RespondToV2Message);
AddMessageResponder("who is MediaBrowserServer_v2?", false, RespondToV2Message)

Relevant code references:
First
Second

[sparky8251]

And going by this bit of code, the random udp port is for at least a specific bit of LiveTV support (possibly all).

[sparky8251]

Looks like the random port is what a network tuner is told to send the LiveTV streams to.

[JustAMan]

Closed by #4.