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HPE Auto Port Aggregation

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Frequently asked questions
Product details and specifications


HPE APA or Auto Port Aggregation, the link aggregation or trunking product from HPE, provides the ability to logically group two or more physical network ports into a single Fat Pipe, often called a trunk. Network traffic is load balanced across all of the links in the aggregation, which allows you to build large bandwidth logical links into the server that are highly available and completely transparent to the client and server applications.

In addition to increased performance, enterprise users require protection against business interruptions and loss of productivity. HPE APA features automatic link failure detection and the ability to transfer traffic to one of the specified redundant links. This is done transparently to the applications to ensure a highly available environment.

November 2017 Release (B.11.31.1711) for HP-UX 11i v3

The November 2017 release consists of a fix to the warning of WEB1705. For more information on this release, see the HP-UX Auto Port Aggregation (APA) Software product documentation page.

Features and Benefits

HPE APA provides the following key benefits:

  • Bandwidth scalability: Allows scaling of networks to improve aggregate throughput.
  • High availability: Provides redundancy or link aggregation of network ports.
  • Load balancing: Supports load balancing and failure recovery capabilities and distributes traffic evenly across the aggregated links, based on IP, TCP Port, or MAC address.
  • Single MAC address: Assigns one single logical MAC address to an aggregate and all its ports.
  • Flexibility: Allows addition and deletion of ports in an aggregate to achieve desired performance whenever needed.
  • Investment protection: Utilizes Ethernet technology, which provides a natural upgrade path for current Ethernet installations, leveraging existing end-stations, management tools and training.
  • Lower IT costs: Provides automated configuration and management tools using the IEEE 802.3ad or PAgP standards.

HPE APA allows the following configuration modes:

  • FEC_AUTO: Used for link aggregates on HPE servers that are connected to a switch that supports Cisco's FastEtherChannel (FEC) protocol, also known as PAgP.
  • LACP_AUTO: Used for link aggregates on HPE servers that are connected to a switch that supports IEEE 802.3ad (LACP) protocol.
  • LAN_MONITOR: Used for failover group configuration on HPE servers.

WARNING for WEB1705 for APA


A memory corruption reported with HP-UX APA B.11.31.1705 on ALLOCB_MBLK_LM caused by Better Link Failure Detection (BLFD) feature. The BLFD was first introduced in APA B.11.31.1603, but the memory corruption problem is just exposed by the enhancements which released in APA B.11.31.1705. A known trigger of this problem is link down. As of today, HPE has got incidents on HP-UX system with APA B.11.31.1705 only. Risk of corruption in B.11.31.1603 exists, but low.


Disable the BLFD feature by following adb command and reboot.

$ print "adb_better_link_failure?W 0x0" | adb -o -w /stand/vmunix /dev/kmem

Please note that the command must be run once again if kernel is rebuilt. And disabling BLFD feature will limit our capability in troubleshooting APA issue.


HPE has released a solution in this APA version (November 2017).

Product Documentation

For detailed information, including installation, configuration, and troubleshooting, see the following documents at the HP-UX Auto Port Aggregation (APA) Software product documentation page.

  • HP Auto Port Aggregation (APA) Administrator's Guide for HP-UX 11i v3
  • HPE Auto Port Aggregation (APA) Release Notes for 11i v3
Additional product information
Product #: HPUX-APA
Version: B.11.31.1711
Software specification: HP-UX 11.31 for IA/PA (J4240AA_B.11.31.1711_HP-UX_B.11.31_IA_PA.depot)
HP-UX 11.31 for IA/PA (J4240AA_B.11.31.1705_HP-UX_B.11.31_IA_PA.depot)
HP-UX 11.31 for IA/PA (J4240AA_B.11.31.1603_HP-UX_B.11.31_IA_PA.depot)
HP-UX 11.31 for IA/PA (J4240AA_B.11.31.1505_HP-UX_B.11.31_IA_PA.depot)
HP-UX 11.31 for IA/PA (J4240AA_B.11.31.1503_HP-UX_B.11.31_IA_PA.depot)
HPE Auto Port Aggregation Release Notes for HP-UX 11i v3 (766139-006.pdf)