Adaptive Load Balancing (ALB)

Adaptive Load Balancing (ALB) evenly distributes data flows across aggregated Ethernet member links. Network administrators use this feature to manage uneven or overloaded data flows on member links. ALB supports up to 32 member links and up to 50 aggregated Ethernet bundles. The algorithm determines which link to use by considering the scanned packet or bit rate associated with each hash value in conjunction with the mapping of hash values to a given link. ALB is applied to IPv4, IPv6, and MPLS packet headers. ALB is disabled by default.

You can configure ALB by setting the adaptive statement at the [edit interfaces ae-interface aggregated-ether-options load-balance] hierarchy level. Under the adaptive statement, you can set the following ALB options:

• tolerance percentage-Allowed deviation, in percentage, in the rates among the members of an aggregated Ethernet bundle. When the tolerance is exceeded, the software performs an adaptive update. The range is 1 through 100. The default is 20.
• scan-interval interval-Scan interval, in multiples of 30 seconds, at which to check the tolerance deviation. The range is 1 to 5. The default is 1. 
• pps-Scan traffic in packets per second (pps). The default is bits per second.