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IP CEF

Hi,

I want to enable "ip cef" in our core routers that consist of two Catalyst 6509 running hybrid mode "IOS:121-20, CatOS:7.6.6"

Any advice, issue. Also, did I need to enable "ip cef" in our access, distribution and server farm switches.

Thanks

3 REPLIES

Re: IP CEF

Hello there,

I believe CEF is the best switching methods to run in any switch.

CEF offers the following benefits:

Improved performance—CEF is less CPU-intensive than fast switching route caching. More CPU processing power can be dedicated to Layer 3 services such as quality of service (QoS) and encryption.

Scalability—CEF offers full switching capacity at each line card when distributed CEF (dCEF) mode is active.

Resilience—CEF offers unprecedented level of switching consistency and stability in large dynamic networks. In dynamic networks, fast switching cache entries are frequently invalidated due to routing changes. These changes can cause traffic to be process switched using the routing table, rather than fast switched using the route cache. Because the Forwarding Information Base (FIB) lookup table contains all known routes that exist in the routing table, it eliminates route cache maintenance and the fast switch/process switch forwarding scenario. CEF can switch traffic more efficiently than typical demand caching schemes.

Although you can use CEF in any part of a network, it is designed for high-performance, highly resilient Layer 3 IP backbone switching.

So, I guess it wont hurt enabling it on your switches.

Please let me know if it helps.

Vlad

New Member

Re: IP CEF

Thanks for the explanation. I want enable it on Catalysty 6509 "core router running hybrid mode" and on all Catalyst 4507 "Server Farm switches".

1) the command to enable it on Catalyst 6509 and 4507 have any options "accounting, distributed, linecard, load-sharing, table and traffic-statistics". Which one I need to choose that fit in our environment.

2) Did I to enable ant things in CatOS.

Thanks

Cisco Employee

Re: IP CEF

IP CEF is enabled by default on most newer Catalyst switches and there is no configuration needed to enable it.

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