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The message CAM IP partition warning appears repeatedly in syslog.

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TitleThe message CAM IP partition warning appears repeatedly in syslog.
Symptoms
A user receiving a large number of IPv4 routes over BGP may see messages such as the following appear in syslog:

Apr 5 17:44:45:A:CAM IP partition warning: total 393216, free 51, slot 1, ppcr 0
Apr 5 17:39:42:A:CAM IP partition warning: total 393216, free 59, slot 1, ppcr 0
Apr 5 17:35:07:A:CAM IP partition warning: total 393216, free 61, slot 1, ppcr 0
Apr 5 17:30:34:A:CAM IP partition warning: total 393216, free 46, slot 1, ppcr 0
Apr 5 17:25:01:A:CAM IP partition warning: total 393216, free 53, slot 1, ppcr 0
Apr 5 17:19:51:A:CAM IP partition warning: total 393216, free 46, slot 1, ppcr 0
Apr 5 17:14:25:A:CAM IP partition warning: total 393216, free 53, slot 1, ppcr 0
Apr 5 17:09:20:A:CAM IP partition warning: total 393216, free 47, slot 1, ppcr 0


The total number will be close to but just under the maximum number of IPv4 CAM entries allowed under the configured CAM partition profile. If no CAM partition profile is configured, then the default CAMpartition profile is used.

For example, the messages above are from an XMRsystem running 5.1.00c configured for "cam-partition profile multi-service-2". On an XMR running 5.1.00c, the profile "multi-service-2" allows for 384K IPv4 CAM entries. 384 x 1024 = 393216.

Each version of the NetIron Configuration Guide contains tables such as "CAM partitioning profiles available for Brocade NetIron XMR routers", "CAM partitioning profiles available for Brocade MLX Series routers", "CAM partitioning profiles available for the 8x10G-D modules", and "CAM partitioning profiles available for the 2x100GbE modules". Each of these tables lists the number of IPv4 CAMentries allowed under each profile.
Environment
Software Release: All NetIron software releases.
Fixed in Version: N/A
Cause
The root cause is insufficient IPv4 CAM compared to the number of IPv4 routes received.
Resolution
Use a different CAM partition profile with more IPv4 entries that is also appropriate to your environment.

For example, if you have "cam-partition profile multi-service-2" configured but you are not using IPv6 routing at all, you can use a different CAMpartition profile with fewer or no IPv6 CAMentries: ipv4-ipv6-2 (more IPv4 CAM, less IPv6 CAM), ipv4 (much more IPv4, no IPv6 CAM). If you are using your XMR or MLXexclusively for IPv4 routing by configuring IP addresses directly on physical interfaces and you do nothave any VLANs configured, you can use a different CAM partition profile with fewer or no "MAC or VPLS MAC" entries.

You can also use "show ip route summary" to see the numbers of IPv4 routes you are receiving over BGP. CAM entry creation is affected both by routes received and traffic that passes through, so "show ip route summary" will not tell you exactly how many CAM entries you need.It will show you the maximum number of CAM entries you could possibly need for the number of routes you are receiving.
Additional notes
Implement route maps to decrease the number of IPv4 routes you arereceiving over BGP.

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