Managing SNAplus2 Clients

Client Networking Requirements

Client Networking Requirements

Before you can run SNAplus2 on a client computer, you must configure TCP/IP port addresses on both the clients and servers in your network. If you encounter problems with the default port assignments, you may need to resolve conflicts as described in “Setting Up IP Port Numbers”.

In addition, you may wish to set clients up so that the TCP/IP connection is dropped automatically when the client is finished using SNAplus2, as described in “LAN Access Timeout”.

Setting Up IP Port Numbers

SNAplus2 uses both TCP/IP and UDP/IP communications to send client/server data across the LAN. By default, it uses the port number 1553 for both types of communications. For most installations, this port number should be suitable; you do not need to change it.

If you encounter problems enabling the SNAplus2 software, check the error log file for messages indicating that the port number used by SNAplus2 clashes with the port number used by another program. If you find such messages, take the following steps:

Step 1. Check the /etc/services file on the computer where the error occurred, to see if another program is listed as using the port number 1553 for either TCP/IP or UDP/IP communications. If this is the case, first try to change the other program to use a different port.

Step 2. If you cannot do this, or if no program is listed as using port 1553, find another port number that is not listed in the file as being used by any program. Check the /etc/services file on all other SNAplus2 computers in the same domain, to ensure that the number is not used on any other computer.

Step 3. In the /etc/services file on each computer in the domain, add two lines in the following form:

sna-cs nnnn/tcp

sna-cs nnnn/udp

The nnnn entry is the new port number. This must be set to the same value on all computers in the SNAplus2 domain.

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