Configuring Load Balancing on a LAG Link
You can configure the load balancing hash key for Layer 2 traffic to use fields in the Layer 3 and Layer 4 headers inside the frame payload for load-balancing purposes using the payload statement. You can configure the statement to look at layer-3 (and source-ip-only or destination-ip-only packet header fields) or layer-4 fields. You configure this statement at the [edit forwarding-options hash-key family multiservice] hierarchy level.
You can configure Layer 3 or Layer 4 options, or both. The source-ip-only or destination-ip-only options are mutually exclusive. The layer-3-only statement is not available on MX Series routers.
By default, Junos implementation of 802.3ad balances traffic across the member links within an aggregated Ethernet bundle based on the Layer 3 information carried in the packet.
For more information about link aggregation group (LAG) configuration, see the Junos OS Network Interfaces Library for Routing Devices.