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LACP

Link Aggregation Control Protocol

Within the IEEE specification, the Link Aggregation Control Protocol (LACP) provides a method to control the bundling of several physical ports together to form a single logical channel. LACP allows a network device to negotiate an automatic bundling of links by sending LACP packets to the peer (directly connected device that also implements LACP).

LACP Features and practical examples

    • Maximum number of bundled ports allowed in the port channel: Valid values are usually from 1 to 8.

  • LACP packets are sent with multicast group MAC address 01:80:c2:00:00:02 (01-80-c2-00-00-02)

  • During LACP detection period

  • LACP packets are transmitted every second

  • Keep alive mechanism for link member: (default: slow = 30s, fast=1s)

  • LACP can have the port-channel load-balance mode :

  • link (link-id) Integer that identifies the member link for load balancing. The range is from 1 to 8.

  • LACP mode :

  • active: Enables LACP unconditionally.

  • passive: Enables LACP only when an LACP device is detected. (This is the default state)