This scenario is found in medium to large deployments in which services routers are placed between two pairs of routers. OSPF is used to control the traffic flow through the nodes in the cluster, and JSRP is used to synchronize the sessions between the two nodes. Since asymmetric routing is supported, traffic does not have to be forced to a particular node. If a failure occurs and return traffic for a session arrives asymmetrically, the fabric link is used to send the traffic back to the node in which sessions are active, which will be the node hosting the egress interface for that particular session.
This scenario benefits from the use of full-mesh connectivity between the devices, which improves the resiliency of the network while eliminating the need to add extra switches between the firewalls and routers and also reducing the number of network failure points.
Figure 77: Active/Active Full Mesh Chassis Cluster Scenario
