Explains how redundant RAP Ethernet daisy chains allow RAPs to be connected using wired Ethernet to avoid latency in backhaul link failure recovery.
A redundant RAP Ethernet daisy chain is a network topology feature that
-
connects Root APs (RAPs) in a sequence using wired Ethernet links
-
provides redundant paths with two switches acting as designated ports for failover, and
-
minimizes latency in backhaul link failure recovery by reversing data flow through a new STP root.
This feature proposes a redundancy in the daisy chain, wherein two switches act as a redundant Designated Port, each connected to either end of the daisy chain. In case of a link failure, the link direction is reversed using a new STP root.
A redundant RAP Ethernet daisy chain shares capabilities with the mesh daisy chain feature. Both topologies provide redundancy and improve network resiliency. In the redundant RAP Ethernet daisy chain topology, each AP encapsulates a packet with a CAPWAP header and forwards it from its wireless client to the controller. The AP bridges the packet from its secondary Ethernet interface to its primary Ethernet interface, including CAPWAP packets sent from other APs' wireless clients. Both 2.4 GHz and 5 GHz radios are available for client access.
Redundant RAP Ethernet daisy chain is supported on the IW6300 AP model.
The daisy chain strict RAP configuration is applicable to Cisco IOS APs only.
If a CAPWAP loss occurs on the first RAP connected to the switch in an Ethernet daisy chain topology, the entire chain loses its uplink, causing a long recovery time. When the RAP Ethernet daisy chain is enabled, the CAPWAP data keepalive interval increases threefold.
Only the wired uplink configuration is valid when an AP is configured as a Bridge or Flex Bridge mode Root AP.