OSA VLAN

The IBM® Open Systems Adapter provides support for IEEE standards 802.1p/q, which describes priority tagging and VLAN identifier tagging. Deploying VLAN IDs allows a physical LAN to be partitioned or subdivided into discrete virtual LANs. This support is provided by the z/OS® TCP/IP stack and the OSA-Express feature in QDIO mode.

When you use VLAN IDs, the z/OS TCP/IP stack can have multiple connections to the same OSA-Express feature. One connection is allowed for each unique combination of VLAN ID and IP version (IPv4 or IPv6). Each connection is defined by an INTERFACE statement and uses one channel unit address for communication, which is assigned by VTAM® from the DATAPATH parameter of the TRLE definition. To configure one or more VLANs for a single OSA-Express feature, take the following steps:

• Configure each IPv4 interface for this OSA-Express feature in the TCP/IP profile by using the INTERFACE statement for IPAQENET, rather than the DEVICE, LINK, and HOME statements. Configure each IPv6 interface for this OSA-Express feature in the TCP/IP profile by using the INTERFACE statement for IPAQENET6.
• Configure a VLANID value on each IPv4 INTERFACE statement and each IPv6 INTERFACE statement on this stack for this OSA-Express feature. Within each IP version, these VLANID values must be unique.
• Configure the VMAC parameter on each of the INTERFACE statements with the default ROUTEALL attribute. You can specify the VMAC address or OSA can generate it. If you specify a VMAC address, it must be unique for each INTERFACE statement.
• Configure a unique subnet for each IPv4 interface for this OSA-Express feature, by using the subnet mask specification on the IPADDR parameter on the INTERFACE statement.
• If you are using OMPROUTE and OMPROUTE is not configured to ignore this interface, ensure that the subnet mask value that you configure on the INTERFACE statement in the TCP/IP profile matches the subnet mask that is used by OMPROUTE for this interface. The subnet mask that OMPROUTE uses is the subnet mask value that is defined on the corresponding OMPROUTE statement (OSPF_INTERFACE, RIP_INTERFACE, or INTERFACE) for this interface. If no OMPROUTE statement is specified for this interface, the subnet mask that OMPROUTE uses is the class mask for the interface IP address.
• Ensure that a DATAPATH device is available in the TRLE definition for each IPv4 interface and for each IPv6 interface for this OSA-Express feature.
• Ensure that you understand the fixed storage requirements for this configuration; each interface requires its own DATAPATH device, and each DATAPATH device requires fixed storage for read processing. For more information, see Fixed storage requirements for OSA-Express QDIO and HiperSockets interfaces.