Ephemeral or dynamic ports are used by every server and client for short lived communications.
When a connection is made _to_ a server via a specific port (in the case of CA Process Automation to an agent using port 7003) we know the port we are connecting to.
But, the server or client that the connection is coming _from_ uses a random available port from its ephemeral port range.
When the communication is complete, the connection will enter a TIME_WAIT state. After the default delay of 4 minutes (240 seconds), it will be able to be reused.
With the change in the range beginning with Windows 2008, port exhaustion is less likely to be problematic, but the symptoms can still be seeing. Prior to Windows 2008, the ephemeral port range was 1025 - 5000. Beginning with Windows 2008 the default start port is 49152 and the default end port is 65535.
Although port exhaustion is less likely to be problematic with a larger range of available ephemeral ports, the symptoms can still be seen.
Network connectivity errors
Inability to access fileshares
High handle counts
Server appears unresponsive or unable to connect
High numbers of connections in the TIME_WAIT state
This is applicable to Windows servers 2008 through Windows 2016.
Please see the additional information below for hotfix and auto-reuse information.
For Windows 2012, there is a hotfix available from Mircrosoft for exhausted ephemeral ports available here:
For Windows 2016, the above page explains how to use the new auto-reuse port range feature.