Re: [RFC 0/2] Delayed binding of UDP sockets for Quic per-connection sockets

[Eric Dumazet]

On 10/31/2018 08:50 PM, Christoph Paasch wrote:

> What we had here is that we wanted to let a server initiate more than 64K
> connections *while* binding also to a source-IP.
> With TCP the bind() would then pick a source-port and we ended up hitting the
> 64K limit. If we could do an atomic "bind + connect", source-port selection
> could ensure that the 4-tuple is unique.
> 
> Or has something changed in recent times that allows to use the 4-tuple
> matching when doing this with TCP?


Well, yes, although it is not really recent (this came with linux-4.2)

You can now bind to an address only, and let the sport being automatically 
chosen at connect()

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=90c337da1524863838658078ec34241f45d8394d