Link Aggregation Group
Link aggregation allows you to bundle
multiple physical Ethernet links to form a single logical trunk providing enhanced
performance and redundancy. The aggregated trunk is referred to as a Link Aggregation
Group
(LAG). The LAG is viewed as a single logical link by connected devices, the Spanning
Tree
Protocol (STP), IEEE 802.1Q VLANs, and so on. When one physical link in the LAG fails,
the
other links stay up. A small drop in traffic is experienced when the link carrying
the
traffic fails. To configure links to form a LAG, the physical links must be of the
same
speed.
You can use a single interface to configure any of the following LAG types:
- Static LAGs: Static LAGs are manually configured aggregate links containing multiple ports. In static link aggregation, links are added into a LAG without exchanging any control packets between the partner systems. The distribution and collection of frames on static links is determined by the operational status and administrative state of the link.
- Dynamic LAGs: A dynamic LAG type uses the Link Aggregation Control Protocol (LACP) to maintain aggregate links over multiple ports. Typically, two partner systems sharing multiple physical Ethernet links can aggregate a number of those physical links using LACP. LACP creates a LAG on both partner systems and identifies the LAG by the LAG ID. All links with the same administrative key, and all links that are connected to the same partner switch become members of the LAG. LACP PDUs are exchanged between ports on each device to determine if the connection is active. The LAG shuts down ports if their connections are no longer active.
- Keep-alive LAGs: In a keep-alive LAG, a single connection between a single port on two RUCKUS devices is established. In a keep-alive LAG, LACP PDUs are exchanged between the two ports to determine if the connection between the devices is still active. If it is determined that the connection is no longer active, the ports are blocked.