Cisco WS-F6K-DFC3B enterprise networking (router/Catalyst switch/UCS families) Switch / Carrier Ethernet Line Card

The Cisco WS-F6K-DFC3B is a Distributed Forwarding Card, generation 3B, a daughterboard fitted to compatible Catalyst 6500 line cards (including the 6800-series and 6816 modules named in Cisco’s own part description) to give that card local, line-rate Layer 2/3 forwarding rather than relying solely on the chassis supervisor engine. Fitting a DFC to each line card in a chassis distributes the forwarding workload, which matters for chassis running dense 10GbE or high-port-count line cards under heavy traffic. The 3B generation is a mid-point in the DFC family, faster than the original DFC/DFC2 but below the DFC4 fitted to newer cards, so confirm which DFC generation your specific line card and supervisor combination requires before ordering, since they are not universally interchangeable. Tech-Star (UK-based, shipped worldwide) supplies Cisco Catalyst 6500 forwarding cards to keep chassis performance in service.