The protecting node operates in a warm-standby mode. Warm-standby mode of operation is a property of the entire node. In other words, while in the central-standby mode of operation (warm-standby command), only subscribers under the SRRP instances that are in the master state is fully instantiated in the data plane on the central standby node (protecting node). All other subscribers (under the SRRP instances that are in the standby state) is synchronized only in the control plane. However, non-central standby nodes can have a peering connection with a protecting node (OMCR) and at the same time another peering connection with another active BNG node in active/active model. All nodes participating in the OMCR mode of operation must run SR OS Release 12.0 or higher. This model is shown in Figure: Network wide mixing of OMCR and active/active (1:1) model.
The central backup property is configured with the following CLI:
configure
redundancy
multi-chassis
peer 10.1.1.1
warm-standby
The warm-standby keyword configures the chassis to be in the central standby mode of operation. Although the configuration option is configured per peer, the warm-standby functionality is applied per chassis.
Synchronization of IPoE subscribers (config>redundancy>multi-chassis>peer>sync>sub-mgmt ipoe) on the protecting node is only possible if all peers are configured for warm-standby or none are.
To transition from one mode to another (warm to hot), all peers must be administratively shutdown and the warm-standby keyword must be either removed or configured on all peers, depending on the direction of the transition.
Single-homed subscribers are supported in the central standby node, subject to resource limitations.