Implementing TCP Stack Affinity

Connect:Direct® for z/OS® supports TCP/IP connectivity through multiple TCP/IP stacks and does not set stack affinity to any particular TCP/IP stack. You might want to run multiple TCP/IP stacks on the same system to provide network isolation for one or more of your applications. Establishing TCP/IP stack affinity binds all TCP/IP socket communications to that stack, which in turn allocates the proper host domain name resolution configuration datasets to IBM® Connect:Direct. These datasets enable host name lookups to have the desired results.

If TCP/IP stack affinity is required, you must specify the stack using one of the following methods:

  • Define the IP addresses and ports specified in the TCP.LISTEN initialization parameter to a particular TCP/IP stack using CINET
  • Add the following step to the IBM Connect:Direct started task JCL before executing the DMINIT initialization module: