SAS^® components that perform network communications use TCP/IP ephemeral ports. These ports are typically used only within the host system where they are allocated and therefore usually do not need to be opened on a firewall.

SAS features that use ephemeral ports include the following:

• SAS code that acts as a client:
  • FILENAME FTP engine
  • FILENAME EMAIL engine
  • the HTTP procedure
  • a SAS/CONNECT® client that issues a SIGNON statement
     
• SAS Spawner environments such as the following:
    - SAS/CONNECT Spawner
    - SAS® Integration Technologies Object Spawner
    - the servers that they spawn
   

Controlling Ephemeral Ports on z/OS

Beginning with z/OS 2.1, IBM introduced the TCP/IP EPHEMERALPORTS parameter ​​​​​​. When you configure this parameter, SAS clients, Spawners, and Servers will use the ephemeral port range defined by EPHEMERALPORTS.

If you need to restrict the range further, or if EPHEMERALPORTS is not implemented, you can set the following TK environment variables in the TKMVSENV file allocated to the SAS session:

•   set TCP_EPH_MAP_ENABLED=1 
•   set TCP_EPH_MAP_FIRST=beginning-of-port-range 
•   set TCP_EPH_MAP_LAST=end-of-port-range
   

Notes:

• Starting with SAS 9.2, the default setting is TCP_EPH_MAP_ENABLED=1.
• The SAS/CONNECT Spawner’s SASDAEMONPORT does not honor the SAS environment variables TCP_EPH_MAP_FIRST and TCP_EPH_MAP_LAST. To dedicate the SASDAEMONPORT, use the Spawner’s -SASDAEMONSERVICE parameter.
• If the SAS environment variables (TCP_EPH_MAP_FIRST and TCP_EPH_MAP_LAST) specify a port range that differs from the TCP/IP EPHEMERALPORTS parameter, SAS client code and SAS servers will use the SAS defined range.

Operating System and Release Information