07-12-2013 10:32 AM - edited 03-04-2019 08:26 PM
I'm using router 7609 for bgp peering and when i reload the router then i faced following error. Please help me to get rid of this error.
*Jul 12 17:09:36.862: %MLSCEF-SP-STDBY-4-FIB_EXCEPTION_THRESHOLD: Hardware CEF entry usage is at 95% capacity for IPv4 unicast protocol.
*Jul 12 17:09:39.261: %CFIB-SP-STDBY-3-CFIB_EXCEPTION: FIB TCAM exception for IPv4 unicast. Packets through some routes will be dropped.
Use "mls cef maximum-routes" to modify the FIB TCAM partition or/and consider a hardware upgred.
Examine your network and collect the necessary information from this setup.
The only way to recover from this state is by reload the router.
07-12-2013 01:59 PM
Hi Prabin,
Check out this thread - it is relevant to your issue.
https://supportforums.cisco.com/thread/2113775
Best regards,
Peter
07-13-2013 07:44 PM
Hello Peter,
Thank you very much for your response.
I read that post and other forum too. I incresed to maximum value by entering command "
mls cef maximum-routes ip" but again faced same problem.
Is it necessary to change my sup engine 720?
07-15-2013 07:40 AM
Hi Prabin,
please share the output of:
show mls cef max
show mls cef summary
Regds,
-Ankit
07-15-2013 07:10 PM
Dear Ankit,
mls cef maximum-routes ip 239K
Router#sh mls cef maximum-routes
FIB TCAM maximum routes :
=======================
Current :-
-------
IPv4 - 222k
MPLS - 2k (default)
IPv6 + IP Multicast - 16k (default)
Router#sh mls cef summ
Total routes: 229033
IPv4 unicast routes: 226980
IPv4 Multicast routes: 3
MPLS routes: 2048
IPv6 unicast routes: 2
IPv6 multicast routes: 3
EoM routes: 0
I read from post that if the cef value is maximum then there will be increase in CPU processing power. If that happens then will it create a problem and how to solve this one?
With Regards
Prabin
07-15-2013 07:17 PM
You have to choices:
receive less prefixes
or
upgrade hardware.
Nothing else.
07-15-2013 10:18 PM
Hello Prabin,
As you have reached the max limit, than you need to upgrade hardware or else try to reduce the routes. In case of SUP720, i dont think that this will have any impact on the CPU.
Regds,
Ankit Gupta
07-15-2013 08:04 PM
Hi Prabin,
Just curious.
Hope you are peering with Service providers for Internet. If yes, why are you receiving so many routes? You may ask
your provider to reduce or filter at your level as the second option. Pls question whether you need ALL those detailed routes in the first place.
Ashok.
Sent from Cisco Technical Support iPhone App
07-15-2013 08:32 PM
Dear Ashok,
We are peering with 2 ISP and with National Internet Exchange (NIX) also.
I'm not so much expert in BGP so just want to know if we reduce or filter routes then will that create problem?
With Regards,
Prabin
07-16-2013 03:19 AM
Hi Prabin,
Ok. I would suggest you to please go through the following link...
http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a00800c95bb.shtml
You need to do BGP Fine tuning and interact with your providers to apply proper filters wherever possible depends upon what you require instead of accepting FULL routes from all the providers add up to 211K+.
Replacing the hardware is not a good option than re-designing your network to customize to your needs.
With best regards...
Ashok
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