CEF issue on Router 7609

[bo2112260285]

Dear All

I have an issue with cisco 7609. You can refer the topolog below

PCs-------->Router(7609)------------------------->ISP A

                                        ------------------------->ISP B

My router have connected to two Uptream Provider(ISP A,ISP B). Firstly my router already have learned the prefix A from the both Upstream. My router chose ISP A as the best path go to prefix A, so all PCs on the network go on this direction as well. Then I want to change BGP policy to make Router chose ISP B as the best path, so I was configured BGP policy to chose go to ISP B. After that I do the tracert from Router and PCs for checking. My router already gone to prefix A by ISP B, but my PCs still chose ISP A as the best path when go through the  Router. I think there is something wrong with the router's CEF table

Please kindly advise me how to resolve this issue but not effect the service running and  what should I do to prevent this happen again.

Thanks in advance

Best Regards

[paolo bevilacqua]

Check "show ip route x.x.x.x" as first step?

If it is right, but user traffic takes the wrong. you have an RIB / CEF table inconsistency.

You can confirm by looking at the various show ip cef commands.

My personal advice in that case would be to update IOS first, then check it it happens again.

[bo2112260285]

Hi Paolo

Thanks for your responding. I also show ip route firstly, Router still right but PC go the wrong way

I also try to use the below commands, but it did not resolved the issue

clear ip route

clear ip cache

Any advises about this issue without Ugrade IOS,everybody?

Thanks and Best Regards

[paolo bevilacqua]

IOS bugs are only resolved by update.

[marlon.buraga]

The setup that i have before was a

point to point and it runs 2 E1 on "7200" using ip cef, what it does is if you do tracert it alternately passes traffic on both WAN Link,

but it doesnt address latency and bandwith issue, at that time we are running different provider, the setup is from Los Angeles -- Manila,

So that you can fine tune the CEF functionality i used policy base routing and it works well,

[Richard Burts]

Bill

With many BGP policies when you change a policy you then need to clear the BGP neighbor session for the policy to take effect. Did you clear BGP neighbor sessions?

If you did then perhaps we could understand the issue better if you would post some specifics including the show ip BGP for the route and the show ip route for the route.

HTH

Rick

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