Operating and managing IEDN-enabled HiperSockets interfaces

Internal Queued Direct I/O extensions (IQDX) interfaces are dynamically operated. They are started and stopped when the associated OSA-Express for zBX (OSX) interfaces are started and stopped. Optionally, IQDX interfaces can be separately operated if at least one of the associated OSX interfaces is active. If an IQDX interface fails, the TCP/IP stack dynamically attempts recovery, as it does with other configured HiperSockets™ devices and interfaces.

z/OS® Communications Server dynamically allocates two control channels and up to eight data devices for each dynamically created IQDX transport resource list element (TRLE). TCP/IP stacks that share OSX CHPIDs also share dynamically created IQDX TRLEs; each stack uses one of the data devices for the IQDX TRLE. You should configure sufficient subchannels for the Internal Queued Direct I/O (IQD) CHPID that is configured for the IQDX function. For more information about defining IQD CHPIDs and device types, see z/OS HCD Planning.

Routing, IP security, and packet tracing of the dynamic IQDX interfaces is controlled through their associated OSX interfaces; the IQDX interfaces are generally not visible to these functions.

• Routing daemons such as OMPROUTE are aware of only the associated OSX interfaces; the stack does not report IQDX interfaces to OMPROUTE, and static routes cannot reference the dynamic IQDX interfaces. z/OS Communications Server makes the decision to direct traffic over an IQDX interface after the associated OSX interface is chosen as the route for the traffic.
• IQDX interfaces are not directly visible to IP security. If IP security is enabled, then traffic over an IQDX interface inherits the security class (SECCLASS) from the associated OSX interface. For packets that are sent and received over the IQDX interfaces, IPSec filtering applies to the security class of the associated OSX interface.
• Packet tracing of an OSX interface includes traffic that is redirected or received over its associated IQDX interface. If you perform a packet trace for data over an IQDX interface, the trace includes only inbound packets that are discarded before the stack can determine the associated OSX interface.

You can use Netstat reports to display information about dynamically created IQDX interfaces.

• The Netstat DEvlinks/-d report displays information for each IQDX interface, as it does for any defined interface. The Netstat DEvlinks/-d report for a given OSX interface displays how much traffic was rerouted to the associated IQDX interface. For more information about the Netstat DEvlinks/-d report, see z/OS Communications Server: IP System Administrator's Commands.
• You can monitor which IP addresses are reachable over the OSX interfaces and over the associated IQDX interfaces using the Netstat ARp/-R and Netstat ND/-n reports. For more information about the Netstat ARp/-R report and the Netstat ND/-n report, see z/OS Communications Server: IP System Administrator's Commands.
• You can display information about the dynamic IQDX TRLEs and their associated datapath devices by issuing the D NET,ID=trle command or the D NET,TRL,TRLE=trle command. For more information about the DISPLAY ID command and the DISPLAY TRL command, see z/OS Communications Server: SNA Operation.