Network configuration strategy with VLAN

The IBM® OSA-Express VLAN support allows a TCP/IP stack to register a specific VLAN identifier for both IPv4 and IPv6. Note that the VLAN ID for IPv4 can be different than the VLAN ID for IPv6. When a VLAN ID is configured, the following situations occur:

  1. TCP/IP becomes VLAN aware or enabled, and this TCP/IP (IPv4 or IPv6 connection) is considered to be part of the configured VLAN.
  2. During activation, TCP/IP registers the configured VLAN ID value to OSA.
  3. A VLAN ID tag is added to all outbound packets.
  4. OSA filters inbound VLAN ID tagged packets based on the configured VLAN ID.
  5. If this stack is also configured as a router (for example, PRIRouter), the OSA primary router support is extended to this stack, allowing it to serve as the primary router for the configured VLAN ID.

When configuring a z/OS® TCP/IP stack with a VLAN ID, consideration must also be given to how the LAN is partitioned and how the VLAN aware switches are configured.