Subject: Creating Redundant Network Interfaces in AIX 5.2

Audience: Administration

Date: October 12, 2004

The "smit etherchannel" screen provides two alternatives for configuring redundant network adapters. The alternatives are known as "Network Interface Backup" and "EtherChannel".

Network Interface Backup provides one active and one hot standby network adapter. You won't see "Network Interface Backup" in the smit screens. To configure, select "Add An Etherchannel/Link Aggregation" and choose one adapter on the pop-up screen. On the next screen, specify one "Backup Adapter". This creates a "phantom" network adapter, which you specify when creating IP addresses. For example, if you specified ent1 and ent2, the "phantom" adapter would be ent3 (or the next unused entN). No special hardware is required, but the adapters should be connected to a separate switches.

Etherchannel (aka "link aggregation" or "trunking") groups multiple network adapters as one IP address to provide both redundancy and higher bandwidth. Etherchannel adapters must be connected to a single "etherchannel aware" switch. You can select to distribute traffic across the adapters using the standard algorithm or round-robin. This will create a "phantom" adapter, like above, which you specify when creating the IP address.

For more information, see http://publib16.boulder.ibm.com/pseries/en_US/aixbman/commadmn/tcp_etherchannel.htm