They say "connection" but really mean a "state". Handshake completed or
not, a state must be created. Most torrent clients also self limit the
number of "half opened" connections, as not to kill your $200 firewall with
a flood of new states. I've seen a default of between 10 and 50.

On Sun, Jun 21, 2015 at 10:39 AM, Juliusz Chroboczek <
jch@pps.univ-paris-diderot.fr> wrote:

>
>> https://torrentfreak.com/popular-torrents-being-sabotaged-by-ipv6-peer-flood-150619/
>>
>
> That's really strange — it looks like µTorrent is using up a connection
> slot even before the peer has performed the µTP three-way handshake.
>
> -- Juliusz
>
>