WS-X6748-GE-TX output drop and and replace daughter card

unfraget · ‎01-09-2020

hi everybody!

i've issue with output drops on ports of WS-X6748-GE-TX

on WS-X6748-GE-TX installed daughter card WS-F6700-CFC.

we will plan change of daughter card from CFC to DFC3, and if believe links https://www.cisco.com/c/en/us/products/collateral/switches/catalyst-6500-series-switches/white_paper_c11-658388.html

https://www.router-switch.com/pdf/ws-x6748-ge-tx=-datasheet.pdf
it should increase performance.

My questions:
if we replace card, can it solve issue with output drops?

Reza Sharifi · ‎01-09-2020

Hi,

if we replace card, can it solve issue with output drops?

It should help with performance but not so much with output drops on ports.

link:

https://community.cisco.com/t5/networking-documents/understanding-msfc-pfc-and-dfc-roles-in-catalyst-6500-series/ta-p/3108572

HTH

Leo Laohoo · ‎01-09-2020

Is QoS enabled?

unfraget · ‎01-10-2020

we don't have qos policy on 6500's, hence qos is globally disabled

Joseph W. Doherty · ‎01-09-2020

Changing a line card from a CFC to a DFC may, or may not, help performance. First, do you have a supervisor PPS bottleneck? If you do, is a major contributor ingress traffic on the card you wish to upgrade with a DFC? (BTW, there are other considerations to a getting the most out of a 6500 chassis, one of which is whether the whole chassis is running in fabric mode.)

Egress drops is usually due to port congestion overflowing available buffer resources. On a 6748 line card, I recall (?) each bank of 24 gig ports has its own buffer pool, so you want to distribute busy egress ports evenly between the two banks of 24 gig ports on the line card. Further, if you have multiple 6748 line cards, you may want to distribute busy egress ports evenly across line cards too.

unfraget · ‎01-11-2020

our 6500 switches perform only l2 switching function
usually, switch is idle, because handled small volume of traffic, nearly 2 Gbps per slot

sh platform hardware capacity
System Resources
  PFC operating mode: PFC3B
  Supervisor redundancy mode: administratively sso, operationally sso
  Switching resources: Module   Part number               Series      CEF mode
                       1        WS-X6724-SFP              CEF720           CEF
                       2        WS-X6704-10GE             CEF720           CEF
                       3        WS-X6724-SFP              CEF720           CEF
                       5        WS-SUP720-3B          supervisor           CEF
                       6        WS-SUP720-3B          supervisor           CEF
                       9        WS-X6748-GE-TX            CEF720           CEF

Power Resources
  Power supply redundancy mode: administratively redundant
                                operationally redundant
  System power: 2771W, 0W (0%) inline, 1586W (57%) total allocated
  Powered devices: 0 total, 0 Class3, 0 Class2, 0 Class1, 0 Class0, 0 Cisco

Flash/NVRAM Resources
  Usage: Module Device               Bytes:      Total          Used     %Used
         1      dfc#1-bootflash:              15990784             0        0%
         2      dfc#2-bootflash:              15990784             0        0%
         3      dfc#3-bootflash:              15990784        262864        2%
         5      slavenvram:                    1964024        412063       21%
         5      slaveconst_nvram:               129004         17360       13%
         5      slavedisk0:                  257507328     213536768       83%
         5      slavesup-bootdisk:           512024576     333979648       65%
         5      slavebootflash:               65536000        365024        1%
         6  RP  bootflash:                    65536000      49414044       75%
         6  SP  sup-bootdisk:                512073728     383410176       75%
         6  SP  const_nvram:                    129004         17360       13%
         6  SP  nvram:                         1964024        178591        9%
         9      dfc#9-bootflash:              15990784             0        0%

CPU Resources
  CPU utilization: Module             5 seconds       1 minute       5 minutes
                   1                  12% /  1%            12%             12%
                   2                   0% /  0%             1%              1%
                   3                   1% /  0%             1%              1%
                   5  RP               0% /  0%             1%              1%
                   5  SP               4% /  0%             4%              5%
                   6  RP              15% /  3%            12%             13%
                   6  SP              29% /  3%            20%             20%
                   9                   1% /  0%             2%              1%
  Processor memory: Module   Bytes:       Total           Used           %Used
                    1                 199065024       38052440             19%
                    2                 199065024       38618568             19%
                    3                 199065024       38025196             19%
                    5  RP             354110960      120561740             34%
                    5  SP             299769068       99417856             33%
                    6  RP             354124208      178845600             51%
                    6  SP             299804460      104149444             35%
                    9                 199065024       38587872             19%
  I/O memory: Module         Bytes:       Total           Used           %Used
              5  RP                    67108864       16487652             25%
              5  SP                    67108864       13964760             21%
              6  RP                    67108864       16487652             25%
              6  SP                    67108864       13964760             21%

EOBC Resources
  Module                     Packets/sec     Total packets     Dropped packets
  1          Rx:                      33       79760275648                   0
             Tx:                      27        7341443935                  28
  2          Rx:                      12       79760275543                   0
             Tx:                       6        5654020084                1771
  3          Rx:                      17       54234306120                   0
             Tx:                      11        3480518957                1831
  5  RP      Rx:                       0         161214243                6236
             Tx:                       0         160585148                   0
  5  SP      Rx:                       9         447919144                1482
             Tx:                       8         439386827                   0
  6  RP      Rx:                     181       24116279700                3322
             Tx:                     181       24093237741                   0
  6  SP      Rx:                      71       11096672501                4363
             Tx:                      75       11736173399                   0
  9          Rx:                      47       79760275715                   0
             Tx:                      41       10177213441                 262

VLAN Resources
  VLANs: 4094 total, 138 VTP, 213 extended VTP, 15 internal, 3728 free

L2 Forwarding Resources
           MAC Table usage:   Module  Collisions  Total       Used       %Used
                              5                0  65536       2020          3%
                              6                0  65536       2020          3%

             VPN CAM usage:                       Total       Used       %Used
                                                    512          0          0%
L3 Forwarding Resources
             FIB TCAM usage:                     Total        Used       %Used
                  72 bits (IPv4, MPLS, EoM)     196608         105          1%
                 144 bits (IP mcast, IPv6)       32768           8          1%

                     detail:      Protocol                    Used       %Used
                                  IPv4                          99          1%
                                  MPLS                           5          1%
                                  EoM                            1          1%

                                  IPv6                           1          1%
                                  IPv4 mcast                     4          1%
                                  IPv6 mcast                     3          1%

            Adjacency usage:                     Total        Used       %Used
                                               1048576         186          1%

     Forwarding engine load:
                     Module       pps   peak-pps                     peak-time
                     5         623878    2548982  14:23:31 MSK Thu Oct 3 2019
                     6         638294   22397727  13:05:06 MSK Sun Jul 28 2019

Netflow Resources
          TCAM utilization:       Module       Created      Failed       %Used
                                  5                  1           0          0%
                                  6                  3           0          0%
          ICAM utilization:       Module       Created      Failed       %Used
                                  5                  0           0          0%
                                  6                  0           0          0%

                 Flowmasks:   Mask#   Type        Features
                      IPv4:       0   reserved    none
                      IPv4:       1   unused      none
                      IPv4:       2   unused      none
                      IPv4:       3   reserved    none

                      IPv6:       0   reserved    none
                      IPv6:       1   unused      none
                      IPv6:       2   unused      none
                      IPv6:       3   reserved    none

CPU Rate Limiters Resources
             Rate limiters:       Total         Used      Reserved       %Used
                    Layer 3           9            4             1         44%
                    Layer 2           5            4             3         80%

ACL/QoS TCAM Resources
  Key: ACLent - ACL TCAM entries, ACLmsk - ACL TCAM masks, AND - ANDOR,
       QoSent - QoS TCAM entries, QOSmsk - QoS TCAM masks, OR - ORAND,
       Lbl-in - ingress label, Lbl-eg - egress label, LOUsrc - LOU source,
       LOUdst - LOU destination, ADJ - ACL adjacency

  Module ACLent ACLmsk QoSent QoSmsk Lbl-in Lbl-eg LOUsrc LOUdst  AND  OR  ADJ
  5          1%     2%     1%     1%     1%     1%     0%     0%   0%  0%   1%
  6          1%     2%     1%     1%     1%     1%     0%     0%   0%  0%   1%

L3 Multicast Resources
  IPv4 replication mode: ingress
  IPv6 replication mode: egress
  Bi-directional PIM Designated Forwarder Table usage: 4 total, 0 (0%) used
  Replication capability: Module                              IPv4        IPv6
                          1                                 egress      egress
                          2                                 egress      egress
                          3                                 egress      egress
                          5                                 egress      egress
                          6                                 egress      egress
                          9                                 egress      egress
  MET table Entries: Module                             Total    Used    %Used
                     5                                  65516       0       0%
                     6                                  65516       8       1%

QoS Policer Resources
  Aggregate policers: Module                      Total         Used     %Used
                      6                            1024            1        1%
  Microflow policer configurations: Module        Total         Used     %Used
                                    6                64            1        1%

Switch Fabric Resources
  Bus utilization: current: 1%, peak was 45% at 20:46:59 MSK Tue Apr 2 2019
  Fabric utilization:     Ingress                    Egress
    Module  Chanl  Speed  rate  peak                 rate  peak
    1       0        20G    2%   13% @09:50 28Feb19    2%   53% @20:47 02Apr19
    2       0        20G    7%   56% @20:47 02Apr19    6%   43% @18:29 01Sep18
    2       1        20G    7%   39% @18:29 01Sep18    8%   46% @21:21 20Apr18
    3       0        20G    2%    9% @20:06 29Mar19    2%   35% @03:10 28Sep18
    5       0        20G    0%    1% @07:24 05Jan20    0%    4% @16:02 17Aug18
    6       0        20G    0%   25% @19:16 26Apr18    0%   25% @19:16 26Apr18
    9       0        20G    2%   14% @17:38 21Jan19    1%   22% @20:01 08May15
    9       1        20G    1%   15% @21:17 04May15    1%   38% @12:21 27Apr18
  Switching mode: Module                                        Switching mode
                  1                                                       acef
                  2                                                       acef
                  3                                                       acef
                  5                                                   crossbar
                  6                                                       dcef
                  9                                                       acef

Interface Resources
  Interface drops:
    Module    Total drops:    Tx            Rx      Highest drop port:  Tx  Rx
    1                    6652760             0                           9   0
    3                   13457427             0                           2   0
    9                    1755953             0                          19   0

  Interface buffer sizes:
    Module                            Bytes:     Tx buffer           Rx buffer
    1     (asic-1)                                 1221120              152000
    2     (asic-1)                                14622592             1914304
    3     (asic-1)                                 1221120              152000
    9     (asic-1)                                 1221120              152000
IBC Resources
  Module                     Packets/sec     Total packets     Dropped packets
  5  RP      Rx:                       0           2714972                   0
             Tx:                       0           2714972                   0
  5  SP      Rx:                       1         243472415                   0
             Tx:                       0           2715119                   0
  6  RP      Rx:                     330        1223190223                   3
             Tx:                     313        1147024394                   0
  6  SP      Rx:                      68       26825191594              523548
             Tx:                      23       35417883169                   0

SPAN Resources
  Source sessions: 16 maximum, 0 used
    Type                             Max      Used
    Local                              2(*)      0
    Local-tx                          14         0
    RSPAN source                       2(*)      0
    ERSPAN source                      2(*)      0
    Capture                            1(*)      0
    Service module                     1(*)      0
    OAM loopback                       1(*)      0
      * - shared source sessions and the total can not exceed 2
  Destination sessions: 64 maximum, 0 used
    Type                             Max      Used
    RSPAN destination                 64(*)      0
    ERSPAN destination                23(*)      0
      * - shared destination sessions and the total can not exceed 64

Multicast LTL Resources
  Usage:   30656 Total, 1783 Used

where from appear output drop, if volume of traffic is very small?

Joseph W. Doherty · ‎01-11-2020

Are you familiar with microbursts? If not, Google it.

If you have those, they can over run buffers, causing drops, yet overall usage statistics can remain low.