Cisco Catalyst 6500

[1] A 6500 comprises a chassis, power supplies, one or two supervisors, line cards, and service modules.

The line cards provide port connectivity and service modules to allow for devices such as firewalls to be integrated within the switch.

The supervisor has connections to the switching fabric and classic bus, as well as bootflash for the Cisco IOS software.

And, able to perform routing functions (e.g. Layer 3) operations, the switch must be run in hybrid mode.

CatOS does have some missing functionality, and[2] is generally considered 'obsolete' compared to running a switch in Native Mode.

In this instance, the user is unaware of where a command is being executed on the switch, even though technically two IOS images are loaded—one on each processor.

[3] Additional to this is the ability to perform patching of processes without rebooting the device and in-service upgrades.

The supervisor then looks up the correct egress port, access lists, policing, and any relevant rewrite information on the PFC.

In this mode, assuming all line cards have a switch fabric connection, an ingress packet is queued as before and its headers are sent along the dBus to the supervisor.

The receiving line card queues the egress packet before sending it from the desired port.

This eliminates the need for any connection to the classic bus or the requirement to use the shared resource of the supervisor.

This mode of operation acts identically to dCEF256, except with 2x20 gb connections to the switch fabric.

When running in Redundant mode, each power supply provides approximately 50% of its capacity to the chassis.

In the event of a failure, the unaffected power supply will then provide 100% of its capacity and an alert will be generated.

To prevent bus errors, the chassis has three pins in each slot that correspond with the line card.

Finally, the shortest pin removes the bus stall and allows the chassis to continue operation.

However, if any part of this operation is skipped, errors will occur (resulting in a stalled bus and ultimately a chassis reload).