How can the same TCP port show in netstat as BOUND and ESTABLISHED in Windows?

Question

I'm investigating an issue of port exhaustion in Windows, and the output of netstat shows many ports both as BOUND and ESTABLISHED

...
TCP    10.0.1.9:64318         10.0.1.9:8400          ESTABLISHED     10348
...
TCP    0.0.0.0:64318          0.0.0.0:0              BOUND           10348
...

How could that happen ?

Update: from my understanding BOUND is a transitory state for a socket, that normally should not appear in netstat's output (and in fact it almost never appears).

In the example above there's an established connection between 2 programs in the same machine.

Port 8400 is bound to a listening socket in the server program. Port 64318 is bound (by the system) to a connected socket in the client program.

I can see no logical explanation for how can port 64318 also show up as a BOUND socket.

But it does.

Answer 1

netstat output describes it very well. Basically, an ephemeral port brought up for a connection then removed from the listening state once a connection has been established.