From: Bart Groeneveld > Sent: 28 August 2020 21:40 > > IANA specifies User ports as 1024-49151, > and Private ports (local/ephemeral/dynamic/w/e) as 49152-65535 [1]. > > This means Linux uses 32768-49151 'illegally'. > This is not just a matter of following specifications: > IANA actually assigns numbers in this range [1]. Linux is using the 'historic' values. IANA shouldn't really have 'grabbed' half the port number space. Really the 'problem' of TCP port numbers identifying the service as well as the connection should have been addresses by some other means (eg using port 1023 and a TCP option to select the serivce). Changing the default base from 32k to 48k will break some existing systems if/when a kernel upgrade is installed. You are also changing the numbers for UDP. Anyone doing a lot of RTP (which typically requires 2 adjacent UDP ports) is already constrained by the availability or ports. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
