Link Aggregation Control Protocol (LACP)

Network Administration Guide for Hitachi NAS Platform

Part Number

The server supports the Link Aggregation Control Protocol (LACP), which it uses to manage an individual link's transmission state (within a Link Aggregation Group). The server controls the LACP relationship between multiple switches. The server determines which network interfaces are in use and can bring up alternative network interfaces during a failure. For example, if the server does not receive any LACP messages from the primary switch (the waiting time is determined by the configured LACP timeout), the server can use the network interfaces connected to the secondary switch instead.

LACP aggregates are not automatically created or populated. The administrator must first create an aggregate interface, then enable LACP on that interface.

Note: The server always sends LACP data units set to ACTIVE. However, the switch can be in active or passive mode.

LACP timeouts

The server supports both short (one second) and long (30 second) LACP timers. A short timeout is three seconds (three x one second). A long timeout is 90s (three x 30 seconds). Therefore, the link times out after three missed messages. Long timeouts are recommended to upgrade upstream network devices without causing path failover on the server. The default NAS setting is a short timeout.