Strange issue with network connections

Hi, I had a strange issue with network connections.We have a Mail and an Application cluster (3 servers each). However, one Domino Mail Server got some strange errors after a period of time:

The TCP/IP protocol stack reported that it ran out of memory. Consult your network documentation to increase configured memory, or reduce Notes connections by limiting clients (see SERVER_MAXSESSIONS parameter in Notes Admin Guide). - Automatically reducing TCPIP port maximum sessions to 4000. Currently, 1 sessions are in the process of being recycled.

I searched the web for this errors and found some hints to use “netstat -a -n” on the command line. There I got a huge list wish connections to out second mail cluster server in the state CLOSE_WAIT. I then used the command again with -b switch (“netstat -a -n -b”). I then saw, that the CLOSE_WAIT mainly were caused by nrouter.exe and nclrepl.exe.

I restartet the two tasks and the connections then were closed. However, after a period of time, the same problem occured again.

After a “little” investigation I found out, that the second mail server had encryption enabled for the tcpip port (all other servers have not). I disabled it, and afterward the problem no longer occurs.

I hope, this will help someone with the same problem.

Greetings

Markus

Subject: TCP/IP error

Hi Markus,

I think i have the same issue.

Can you tell me where is the parameter to verify (modify) the encryption on Domino server?

Thanks by advance.

Subject: See in Domino Administrator…

Sorry for the late answer…

If you open the server in the Domino Administrator und go to the Server tab you find the point “Ports” and there you can setup the ports of this server.