Cisco WS-F6700-CFC
Catalyst 6500 Central Fwd Card for WS-X67xx modules
Product Highlights
What's Included
Maintaining reliable, high-throughput forwarding across a dense Catalyst 6500 chassis demands that every line card has the right forwarding engine in place. The Cisco WS-F6700-CFC is the Centralized Forwarding Card (CFC) designed specifically for WS-X67xx series CEF720-based Ethernet modules in the Cisco Catalyst 6500 Series.
As a mezzanine daughtercard, the WS-F6700-CFC plugs directly onto a compatible 67xx line card and serves as the base-level forwarding interface between the line card and the Supervisor Engine 720's Policy Feature Card 3 (PFC3). It houses two dedicated ASICs that create compact packet headers and relay them to the central PFC3 for all Layer 2 and Layer 3 forwarding decisions, supporting a centralized forwarding rate of up to 30 Mpps system-wide.
The CFC is the default and essential requirement for WS-X67xx linecard operation in centralized forwarding mode. For environments that require higher aggregate throughput, the WS-F6700-CFC can be field-replaced with a DFC3 distributed forwarding daughtercard to scale performance up to 400 Mpps. This product is part of the Cisco Catalyst 6500 platform, which has reached End-of-Life status — making the WS-F6700-CFC a critical spare for organizations maintaining existing Catalyst 6500 deployments.
Features & Benefits
Centralized Forwarding Engine
The WS-F6700-CFC houses two dedicated ASICs that function as a bus interface, forming compact packet headers that are forwarded to the Supervisor Engine 720's PFC3 for centralized Layer 2 and Layer 3 forwarding decisions. This architecture offloads forwarding tasks from the supervisor engine's control plane, improving overall chassis efficiency.
Essential WS-X67xx Line Card Component
The CFC is the base requirement for all WS-X67xx CEF720-based line card operation in centralized forwarding mode. Without a CFC or DFC daughtercard installed, the 67xx line card cannot participate in the switching fabric. This makes the WS-F6700-CFC a must-have spare for any Catalyst 6500 deployment using 67xx modules.
Field-Upgradeable to Distributed Forwarding
When higher performance is needed, the CFC can be removed and replaced with a DFC3 daughtercard (DFC3A, DFC3B, DFC3BXL, DFC3C, or DFC3CXL) to enable distributed CEF (dCEF) on the line card. This upgrade path scales aggregate system forwarding from 30 Mpps centralized to up to 400 Mpps distributed — without replacing the line card itself.
Compact Mezzanine Design
The WS-F6700-CFC installs as a mezzanine module directly onto the host WS-X67xx Ethernet module. It draws power from the host line card and does not consume a chassis slot, keeping your Catalyst 6500 slot density fully available for additional line cards or service modules.
Deployment Scenarios
Catalyst 6500 Maintenance & Sparing
Organizations running Catalyst 6500 Series switches with WS-X67xx line cards need CFC daughtercards on hand as critical spares. Since the platform has reached End-of-Life, sourcing replacement CFCs ensures continued operation of existing infrastructure without costly forklift upgrades.
Centralized Forwarding Deployments
In environments where centralized forwarding via the Supervisor Engine 720 PFC3 is sufficient — such as campus access or distribution layers with moderate traffic loads — the WS-F6700-CFC provides the required forwarding interface at the lowest cost, reserving DFC upgrades for only the highest-throughput line cards.
Pre-Upgrade Staging for DFC3 Migration
Network teams planning a phased migration to distributed forwarding can deploy WS-X67xx line cards with the default CFC initially, then field-upgrade to DFC3 daughtercards as performance requirements grow — without replacing the line cards or disrupting chassis configuration.
General
Technical
Physical
Compatibility
Environmental
Compatibility Notes
Compatible WS-X67xx Line Cards
The WS-F6700-CFC is designed for installation on the following Cisco Catalyst 6500 CEF720-based Ethernet modules:
- WS-X6704-10GE — 4-port 10 Gigabit Ethernet module
- WS-X6708-10G-3C / WS-X6708-10G-3CXL — 8-port 10 Gigabit Ethernet module (Note: WS-X6708-10G-3C/XL requires a DFC for operation; the CFC alone is not sufficient for this module)
- WS-X6724-SFP — 24-port Gigabit Ethernet SFP module
- WS-X6748-GE-TX — 48-port 10/100/1000 Ethernet module
- WS-X6748-SFP — 48-port Gigabit Ethernet SFP module
Supervisor Engine Requirement
Requires a Supervisor Engine 720 (or Supervisor Engine 2T) with PFC3 for centralized forwarding operation.
Important Notes
- The CFC and DFC3 use the same line card connector and are mutually exclusive — remove the CFC before installing any DFC3 daughtercard.
- When used in VSS mode, the CFC is supported with PFC3C or PFC3CXL supervisor engines.
Downloads & Resources
Frequently Asked Questions
| Part Number | Product | Key Difference |
|---|---|---|
| WS-F6700-DFC3A | Catalyst 6500 DFC3A Distributed Forwarding Card | Adds distributed CEF (dCEF) for local forwarding on the line card, scaling system performance beyond 30 Mpps centralized limit. |
| WS-F6700-DFC3BXL | Catalyst 6500 DFC3BXL Distributed Forwarding Card | Provides distributed forwarding with MPLS support, ACE counters, 1M IPv4 routes, and 256K NetFlow entries. |
| WS-F6700-DFC3C | Catalyst 6500 DFC3C Distributed Forwarding Card | Supports distributed forwarding with full PFC3C-mode features including VSS compatibility with DFC-level performance. |
| WS-F6700-DFC3CXL | Catalyst 6500 DFC3CXL Distributed Forwarding Card | Highest-tier DFC3 option with extended scalability tables and full VSS support — maximum distributed forwarding performance. |
