[c-nsp] Cat 6500 SUP720 environment problems..

John R fraglet at gmail.com
Thu May 10 09:18:09 EDT 2007


  Hello all

We have some questions in relation to our environment, we basically have a
pair of 6509 chassis with sup720-3b`s connecting to lots ( over 300 ) cisco
3020 blade switches, with each 3020 attached to both 6509`s, there are no
DFC`s on the linecards.

The 6500`s have 8 x Gig-E connections as a portchannel between them

The environment runs unicast and multicast but there is no really high
traffic levels, we have some questions relating to below, any comments would
be most welcome.


        6500 --- 8 gig-e portchannel --- 6500
        \                                          /
         \                                        /
          \      300+ 3020 blades      /



Cat6509`s are running both running 12.2.18SXF5 -
ipservicesk9-mz.122-18.SXF5.bin

CAT6KSUP720-3B#sh cat
  chassis MAC addresses: 1024 addresses from 0018.7433.3400 to
0018.7433.37ff
  traffic meter =   1%   Last cleared at 13:22:27 GMT Thu Nov 9 2006
           peak =  96%        reached at 01:12:36 BST Thu May 10 2007
  switching-clock: clock switchover and system reset is allowed

Q - Is this peak only for the shared bus ?

######################################################################################

CAT6KSUP720-3B#sh pla ha cap for
L2 Forwarding Resources
           MAC Table usage:   Module  Collisions  Total       Used
%Used
                              5                0  65536       2905
 4%

             VPN CAM usage:                       Total       Used
%Used
                                                    512          0
 0%
L3 Forwarding Resources
             FIB TCAM usage:                     Total        Used
%Used
                  72 bits (IPv4, MPLS, EoM)     196608        4232
 2%
                 144 bits (IP mcast, IPv6)       32768        1483
 5%

                     detail:      Protocol                    Used
%Used
                                  IPv4                        4232
 2%
                                  MPLS                           0
 0%
                                  EoM                            0
 0%

                                  IPv6                           2
 1%
                                  IPv4 mcast                  1481
 5%
                                  IPv6 mcast                     0
 0%

            Adjacency usage:                     Total        Used
%Used
                                               1048576        4194
 1%

     Forwarding engine load:
                     Module       pps   peak-pps
peak-time
                     5         616391    9068315  15:29:21 GMT Mon Dec 18
2006

Q - Is the peak-pps the largest peak seen by the PFC
Q - If it is, is this not well short of the 30mpps that the box should be
able to support

######################################################################################

CAT6KSUP720-3B#sh ibc brief
Interface information:
        Interface IBC0/0(idb 0x51E4F010)
        Hardware is Mistral IBC (revision 5)
        5 minute rx rate 134000 bits/sec, 60 packets/sec
        5 minute tx rate 76000 bits/sec, 48 packets/sec
        801981457 packets input, 158150852481 bytes
        571784929 broadcasts received
        615169009 packets output, 150564832578 bytes
        65392127 broadcasts sent
        1 Inband input packet drops
        0 Bridge Packet loopback drops
        50002482 Packets CEF Switched, 118971932 Packets Fast Switched
        0 Packets SLB Switched, 0 Packets CWAN Switched
        IBC resets   = 1; last at 14:25:38.107 gmt Sat Oct 28 2006
MISTRAL ERROR COUNTERS
        System address timeouts  = 0     BUS errors     = 0
        IBC Address timeouts     = 0 (addr 0x0)
        Page CRC errors          = 0     IBL CRC errors = 0
        ECC Correctable errors   = 0
        Packets with padding removed (0/0/0)   = 0
        Packets expanded (0/0)   = 0
        Packets attempted tail end expansion > 1 page and were dropped = 0
        IP packets dropped with frag offset of 1 = 0
        1696 packets (aggregate) dropped on throttled interfaces
        Hazard Illegal packet length     = 0     Illegal Offset       = 0
        Hazard Packet underflow          = 0     Packet Overflow      = 0
        IBL fill hang count              = 0     Unencapsed packets   = 0
        LBIC RXQ Drop pkt count = 0            LBIC drop pkt count  = 0
        LBIC Drop pkt stick     = 0

The CEF counter is not clocking in this instance, whereas the fast switch
counter is, our understanding is that the IBC is the bus between the SP and
RP?

Q - Why do we see so many fast switches packets
Q - Should the CEF counter not increment



######################################################################################

CAT6KSUP720-3B#sh ip mroute count ters
IP Multicast Statistics
730 routes using 681034 bytes of memory
21 groups, 33.76 average sources per group

Q - The above is the avergae mcast count for the box, this to us doesn't
seem high ?
Q - With lots of multicast boundary commands configured can this add to load
?

######################################################################################

CAT6KSUP720-3B#      sh mod
Mod Ports Card Type                              Model              Serial
No.
--- ----- -------------------------------------- ------------------
-----------
  1   48  CEF720 48 port 1000mb SFP              WS-X6748-SFP
SAL1025XXXX
  2   48  CEF720 48 port 1000mb SFP              WS-X6748-SFP
SAL1026XXXX
  3   48  CEF720 48 port 1000mb SFP              WS-X6748-SFP
SAL1026XXXX
  4   48  CEF720 48 port 1000mb SFP              WS-X6748-SFP
SAL1026XXXX
  5    2  Supervisor Engine 720 (Active)         WS-SUP720-3B
SAL1028XXXX
  6   48  CEF720 48 port 1000mb SFP              WS-X6748-SFP
SAL1025XXXX
  7   48  CEF720 48 port 1000mb SFP              WS-X6748-SFP
SAL1026XXXX
  8   48  CEF720 48 port 1000mb SFP              WS-X6748-SFP
SAL1026XXXX
  9   48  CEF720 48 port 1000mb SFP              WS-X6748-SFP
SAL1025XXXX

Q. - Every port on the switch is configured as per the config below, will
this cause problems ?
I.E - Is RMON on every port advisable ?

 rmon collection stats 4 owner "root at mgmtstation [1161348691907]"
 rmon collection history 4 owner "root at mgmtstation [1161348775440]" buckets
50

#####################################################################################

mls aging long 64
mls aging normal 32

Q. - Should the above setting be changed to default times for long and
normal flows ?

#####################################################################################

Q. - We see large numbers of output drops, but little in the way of traffic
between the port-channel connecting the two 6ks together - does this match
the following bug ?

http://www.cisco.com/cgi-bin/Support/Bugtool/onebug.pl?bugid=CSCdv86024


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