Common INET PFS

If you want to run multiple z/OS® Communications Server TCP/IP stacks concurrently, you must use the Common INET (CINET) configuration. In this configuration, up to a maximum of eight TCP/IP stacks can be active at any time.

When the CINET configuration is used, the CINET PFS is inserted between the LFS and the TCP/IP PFS for each stack. The CINET PFS maintains an internal copy of each TCP/IP stack's IP configuration, so that it can preroute a socket call to the correct TCP/IP stack. This allows most socket programs to run with multiple stack support with no change to the application. In addition, CINET supports IPv6, and is capable of supporting underlying TCP/IP stacks in IPv4/IPv6 dual mode or in IPv4-only mode.

You can specify your choice of INET (single stack) or CINET (multiple stack) support on the NETWORK, DOMAINNAME, FILESYSTYPE, and SUBFILESYSTYPE statements of SYS1.PARMLIB(BPXPRMxx). For more information about the BPXPRMxx statements, see Specifying BPXPRMxx values for a CINET configuration and z/OS UNIX System Services Planning.