[f-nsp] CAM IPv6 partition warning even if cam partition not full

[Andreas Schlee]

Hi, on our MLXe running IronWare 6.0.0f we're getting CAM IPv6 partition warnings:

>sh log | in CAM
Sep 26 11:43:25:A:CAM IPv6 partition warning: total 65536 (reserved 0), free 51, slot 3, ppcr 1
Sep 26 11:38:25:A:CAM IPv6 partition warning: total 65536 (reserved 0), free 44, slot 3, ppcr 1
Sep 26 11:33:25:A:CAM IPv6 partition warning: total 65536 (reserved 0), free 22, slot 3, ppcr 1
Sep 26 11:28:25:A:CAM IPv6 partition warning: total 65536 (reserved 0), free 62, slot 3, ppcr 1
Sep 26 11:23:25:A:CAM IPv6 partition warning: total 65536 (reserved 0), free 100, slot 3, ppcr 1
Sep 26 11:18:25:A:CAM IPv6 partition warning: total 65536 (reserved 0), free 43, slot 3, ppcr 1

But the cam partition usage tells us there is still space free:

>show cam-partition usage  slot 3
Slot 3 XPP20SP 0:
[...]
          [IPV6]  65536(size),   10218(free), 084.40%(used)
        :SNet 0:  10470(size),   10207(free), 002.51%(used)
        :SNet 1:  51359(size),       5(free), 099.99%(used)
        :SNet 2:   3268(size),       0(free), 100.00%(used)
        :SNet 3:    377(size),       0(free), 100.00%(used)
        :SNet 4:     45(size),       0(free), 100.00%(used)
        :SNet 5:      9(size),       0(free), 100.00%(used)
        :SNet 6:      2(size),       1(free), 050.00%(used)
        :SNet 7:      2(size),       2(free), 000.00%(used)
        :SNet 8:      2(size),       2(free), 000.00%(used)
        :SNet 9:      2(size),       1(free), 050.00%(used)

>show ipv6 route sum
IPv6 Routing Table - 55032 entries:
  122 connected, 0 static, 0 RIP, 0 OSPF, 54910 BGP, 0 ISIS
  Number of prefixes:
  /16:1 /19:2 /20:11 /21:3 /22:6 /23:4 /24:21 /25:6 /26:15 /27:17
  /28:82 /29:2292 /30:210 /31:123 /32:10733 /33:697 /34:595 /35:419
  /36:2143 /37:403 /38:473 /39:166 /40:2878 /41:379 /42:579 /43:135
  /44:4056 /45:343 /46:1455 /47:521 /48:25424 /50:4 /54:9 /56:39
  /64:243 /112:1 /123:1 /124:5 /125:7 /126:489 /127:9 /128:33
Nexthop Table Entry - 120 entries


So the warning tells us a highly different amount of free entries compared to the log: 10218 <-> 51
We checked the usage about 2 minutes after the warning appeared in the log.

Anyone out there facing or faced the same issue? What information should we trust now: the warning in the log or the cam-partition usage?
Another question would be: what are the "SNet" entries we see in the cam-partition, and why are some of them this small (size of 2)?

Finally, the manual says about partition sharing:
Supernet TCAM partition sharing 
In Brocade NetIron software versions prior to 03.2.00, TCAM resources could not be shared between the 32 levels of the IP Forwarding Information Base (FIB). Beginning with 03.2.00, TCAM allocation is optimized for dynamic allocation of resources to each level. If one level runs out of TCAM resources, it can obtain resources that have been allocated to another level but are unused. This feature applies to IPv4 and Layer 3 VPN routes. 

Does that mean that there is no sharing between the supernets in IPV6 CAM?

Regards,
Andreas Schlee

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