Cisco Mimarisi (MSFC, PFC, CFC, DFC)

Cisco Mimarisindeki Bileşenler ve Görevleri

MSFC (Multilayer Switch Feature Card)

     Multilayer Switch Feature Card is the Layer 3 switching engine that sites on the Catalyst Supervisor as a daughter card.
     The control plane functions in the Cisco Catalyst 6500 are processed by the MSFC and include handling Layer 3 routing protocols, maintaining the routing table, some access control, flow initiation, and other services not found in hardware.

 PFC (Policy Feature Card)

     The PFC3 is the ASIC-based forwarding engine daughtercard for the Sup720; the DFC3 is the ASIC-based forwarding engine daughtercard for various fabric-enabled linecards (CEF256, CEF720). Contains the ASICs that are used to accelerate Layer 2 and Layer 3 switching, store and process QoS and security ACLs, and maintain NetFlow statistics.

Role of PFC Layer 3 Engine

• NetFlow Statistics collection.

• Hardware based forwarding of IPv4, IPv6 and MPLS tagged packets.

• QoS mechanism for ACL classification, marking of packets, and policing (rate limiting).

• Security mechanism for validating ACL rules against incoming packets.

• Maintaining Adjacency entries and statistics.

• Maintaining Security ACL counters.

CFC (Centralized Forwarding Card)

     CFC is a centralized forwarding card for the switching modules which makes IPv4 Routing over the PFC. CFC does not do local forwarding, the forwarding is done by the PFC in the Supervisor. As the forwarding is centralized, the PFC performance, FIB entries, ACL lables are shared among the line cards that uses the Supervisor PFC for forwrding.

DFC (Distributed Forwarding Card)

     The Catalyst 6500 architecture supports the use of Distributed Forwarding Cards (DFC). Distributed Forwarding Card is a combo daughter card comprising a MSFC and PFC used by a fabric enabled Cat6500 linecard to perform distributed switching. DFCs are located in linecards, not in Supervisors.


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