Cajun P550 Switch Overview

Consequently, when you connect a Cajun switch to the network, it begins to receive frames from the network and builds a master routing table in the supervisor module and forwarding tables in each media module based on those frames.

This process creates three distinct results:

❒All known (learned) traffic from Layer 3 modules that requires routing is routed directly in hardware by the Layer 3 media module without a need to traverse the switching fabric to get to the supervisor module’s software routing function.

❒All unknown (not learned) traffic from Layer 3 modules must first be sent to the Layer 3 supervisor module, where information on the frame is added to the supervisor module’s master routing table and added to the appropriate address caches of Layer 3 media modules.

❒Since Layer 2 modules have no routing capability, packets that are received by a Layer 2 module and require routing are routed by sending the packet to the Layer 3 supervisor module. The routing engine on the supervisor module then performs the routing operation for the Layer 2 modules and sends the packet back through the switching fabric to the destination port.

Figure 1-4 shows a conceptual example of how traffic is routed in a Cajun switch.

Figure 1-4.Layer 2/3 Routing with Cajun Switch

L2/L3

L2/L3

L2/L3

Supervisor

Supervisor

Supervisor

L2/L3 I/O Module

L2/L3 I/O Module

L2/L3 I/O Module

L2 I/O Module

L2/L3 I/O Module

L2 I/O Module

BetweenL2 I/OModules

BetweenL3L3I/OI/OModulesModules

L2 and L3 I/O Modul

 

BetweenL2 and L3 I/O Modules

Virtual Bridging Functions

The switch design supports:

❒Up to 24,000 MAC addresses in the switch address forwarding table - This feature allows the switch to store forwarding information for hosts in very large networks.

❒Segmented address tables qualified by address and VLAN membership - This feature allows the same host to appear on different VLANs on different ports.

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Cajun P550/P220 Switch Operation Guide