Enterasys Networks 9034385 manual 9 Layer 2 NAC Controller Redundancy

Inline NAC Design Procedures

Figure 5-9 Layer 2 NAC Controller Redundancy

For a Layer 3 NAC Controller, redundancy is achieved by implementing redundant Layer 3 NAC Controllers on adjacent, but separate networks as shown in Figure 5‐10. The NAC Controllers must be in different networks, and a dynamic routing protocol such as OSPF or RIP must be configured between the upstream and downstream routers that are positioned on either side of the NAC Controllers. Redundant Layer 3 NAC Controllers are active‐active, in that traffic from a downstream router may pass through either of the redundant Layer 3 NAC Controllers with equal cost multipath forwarding implemented for the configured dynamic routing protocol. If NAC Controller #1 (PEP or NAC Engine) stops forwarding traffic, the network will automatically converge using the configured routing protocol to forward traffic through NAC Controller #2. Note that the NAC Controllers do not route packets and do not participate in the layer 3 topology.

Figure 5-10 Layer 3 NAC Controller Redundancy

Enterasys NAC Design Guide 5-31