HP UX Auto Port Aggregation (APA) Software Link Aggregate Advanced Parameters, Priority, Cost

Priority

The port priority in a failover group (LAN_MONITOR mode) using priority-based failover or cost-based failover. If you assign a priority value to one link, you must assign a priority value to all links in the failover group. Leave this blank if you do not want to assign a priority value; HP APA will assign it. For the December 2005 and later releases of HP APA for HP-UX 11i v1 (B.11.11.20) and PHNE_33116 (B.11.11.17) patch release.

Cost

The port cost in a failover group (LAN_MONITOR mode) using cost-based failover. A link that has a lower normalized cost (cost divided by the link speed) is preferred over one with a higher normalized cost. When both links have the same normalized cost, the one with the higher priority is preferred. If you assign a cost value to one link, you must assign a cost value to all links in the failover group. Leave this blank if you do not want to assign a cost value; HP APA will assign it.

Link Aggregate Advanced Parameters

Load Distribution Algorithm

The algorithm to use for outbound data transfer. Inbound load balancing and data flow distribution are strictly determined by the link partner and have no affect on the outbound algorithm. For a complete description of load balancing, see “Load Balancing” (page 14). Check the algorithm you want to use. The following choices are available:

LB_MAC	This algorithm uses the least significant byte of the link level destination
	MAC address of the data flow as an index into a table of 256 possible entries.
	The physical port selected will be used to send packets for the duration of
	the specific data flow.
	This is the default algorithm for all link aggregates.
	Recommended Configuration: Server-to-Switch
LB_IP	This algorithm uses the least significant bytes of the source and destination
	IP addresses of the data flow as an index into a table of 256 possible entries.
	Recommended Configuration: Server-to-Router
LB_PORT	This algorithm uses the TCP/UDP source and destination port numbers to
	distribute traffic across the ports in a link aggregate.
	Recommended configuration: Server-to-Server
HOT_STANDBY	This algorithm uses one link in the link aggregate on which to send all
(MANUAL mode	outbound traffic; there is no actual load balancing across the network physical
only)	ports in the link aggregate. The link is the one with highest port priority. If
	the link goes down (for example, cable disconnect), all the traffic on the link
	is automatically switched to a secondary link in the same link aggregate.
	If you chose this option, the ports must be cabled to a switch and the switch
	ports must not be configured for aggregation.

34 Configuring APA