Enabling a secondary port
This procedure describes how to configure existing standalone clients to use the NIMSH communication protocol with a secondary port option enabled.
By default, NIMSH uses a reserved port for returning stderr output during command execution. The default setting allows administrators to specify a specific port for opening behind a firewall, but it can cause performance issues when several connections are attempted in a short amount of time.
When TCP connections are closed, the closing sockets enter TIME_WAIT state. The length of time for this state may last up to 240 seconds depending on system settings. The secondary port option allows you to specify any specific range of ports to cycle through during NIMSH operation.
For firewalls, administrators might want to open a specific range on the firewall, and then for each machine on the internal network, ensure that the port range on the machine coincides with the open range on the firewall. When changing the NIMSH secondary port, you should choose a range of ports outside of the range used for system services. Try using ports 49152 through 65535.