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Multilink PPP or CEF

I'm currently using multilink ppp to bond 5 T1 circuits between a 3825 and a 3725 router. I have read discussions of IP CEF providing improved performance. How much peformance gain if any would there be if one was to use CEF with these routers? Can CEF be applied to the serial interfaces while still using mlppp? Can CEF be used with static routing? My mlppp is working fine but looking for the most efficient way to bond the circuits. A config example of how to setup cef would be appreciated. Please advise.
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setags
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setags
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td_milesCommented:
to use CEF, you just enable it globally:

Router# config t
Router(config)# ip cef

if you are using distributed MLPPP, simply put the work "distributed" after your "ip cef"
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122newft/122t/122t15/mplsdmlp.htm#wp1027265

This discussion of CEF:
http://www.cisco.com/warp/public/cc/pd/iosw/iore/tech/cef_wp.htm

suggests that you would use it when you have a large number of traffic going to multiple destinations, such that the routing entries would not be in the route-cache. Thus using CEF would decrease the time for route lookups. It really depends on your traffic patterns and routes as to whether you will gain any benefit from it. If you have enough memory in the routers, you can turn it on and see what happens, it shouldn't cause anything to be slower.
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setagsAuthor Commented:
In my network configuration I have only two locations connected together via 5T1's bonded (mlppp). It sounds doubtful that I would see any noticeable performance gain if CEF benefits networks with distributed routes. Any thoughts?
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td_milesCommented:
Exactly, if the routes aren't being pushed out of the cache, then you shouldn't see any benefit from CEF. The only time it might help is if you have very high CPU usage on the router. Using CEF might allow you to trade some CPU usage for a little additional memory usage (obviously you would only do this if you have memory to spare).
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