[c-nsp] ASR920 drops despite policy-map

[Jason Lixfeld]

Hey folks,

I have two ASR920s in the lab trying to do an RFC2544 test between them.  I’ve enabled a policy map on the interfaces to adjust the queue depth to 100%.  Despite this, I’m still getting a ton of drops throughout the test.

It’s a pretty simple topology.  Gi0/0/22 on each A920 is connected to an Exfo test set.  Gi0/0/23 on each A920 is connected to the other.  I’ve got an EoMPLS PW connecting Gi0/0/22 on both devices.

Exfo Tester - gi0/0/22 - ASR920-1 - gi0/0/23 - gi0/0/23 - ASR920-2 - gi0/0/22 - Exfo Loopback

The Exfo transmitted 45469372 packets during the test, and I’m seeing output drops on ASR920-1 Gi0/0/23.

There’s no other traffic going across this box, except for ISIS and BFD, but I highly doubt this would contribute to 2.1 million dropped packets.

Is there something different I need to tweak to make these queues behave?

lab01.asr920#sh int gi0/0/22 | i drops|bytes
  MTU 1600 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
  Input queue: 0/375/0/0 (size/max/drops/flushes); Total output drops: 0
     45469610 packets input, 10927759820 bytes, 0 no buffer
     43364152 packets output, 10691346050 bytes, 0 underruns
     0 unknown protocol drops
lab01.asr920#sh int gi0/0/23 | i drops|bytes
  MTU 9202 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
  Input queue: 0/375/0/0 (size/max/drops/flushes); Total output drops: 2105451
     43389175 packets input, 11655717913 bytes, 0 no buffer
     43388248 packets output, 11649932565 bytes, 0 underruns
     0 unknown protocol drops
lab01.asr920#show policy-map int gi0/0/22
 GigabitEthernet0/0/22

  Service-policy output: leaf

    Class-map: class-default (match-any)
      43364152 packets, 10691346050 bytes
      5 minute offered rate 517000 bps, drop rate 0000 bps
      Match: any

      queue limit 100 percent
      (queue depth/total drops/no-buffer drops) 0/0/0
      (pkts output/bytes output) 43364152/10691346050

lab01.asr920#show policy-map int gi0/0/23
 GigabitEthernet0/0/23

  Service-policy output: leaf

    Class-map: class-default (match-any)
      45471434 packets, 10927902092 bytes
      5 minute offered rate 528000 bps, drop rate 0000 bps
      Match: any

      queue limit 100 percent
      (queue depth/total drops/no-buffer drops) 0/2105451/0
      (pkts output/bytes output) 43365983/10691488770

lab01.asr920#


lab02.asr920#sh int gi0/0/22 | i drops|bytes
  MTU 1600 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
  Input queue: 0/375/0/0 (size/max/drops/flushes); Total output drops: 0
     43364152 packets input, 10691346050 bytes, 0 no buffer
     43364157 packets output, 10691346370 bytes, 0 underruns
     0 unknown protocol drops
lab02.asr920#sh int gi0/0/23 | i drops|bytes
  MTU 9202 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
  Input queue: 0/375/0/0 (size/max/drops/flushes); Total output drops: 0
     43388487 packets input, 11649977015 bytes, 0 no buffer
     43389427 packets output, 11655809136 bytes, 0 underruns
     0 unknown protocol drops
lab02.asr920#show policy-map int gi0/0/22
 GigabitEthernet0/0/22

  Service-policy output: leaf

    Class-map: class-default (match-any)
      43364157 packets, 10691346370 bytes
      5 minute offered rate 488000 bps, drop rate 0000 bps
      Match: any

      queue limit 100 percent
      (queue depth/total drops/no-buffer drops) 0/0/0
      (pkts output/bytes output) 43364157/10691346370

lab02.asr920#show policy-map int gi0/0/23
 GigabitEthernet0/0/23

  Service-policy output: leaf

    Class-map: class-default (match-any)
      43366022 packets, 10691491882 bytes
      5 minute offered rate 478000 bps, drop rate 0000 bps
      Match: any

      queue limit 100 percent
      (queue depth/total drops/no-buffer drops) 0/0/0
      (pkts output/bytes output) 43366022/10691491882

lab02.asr920#


lab01.asr920#sh run int gi0/0/22
Building configuration...

Current configuration : 252 bytes

!
interface GigabitEthernet0/0/22
 description Facing Exfo
 mtu 1600
 no ip address
 negotiation auto
 no keepalive
 service-policy output leaf
 service instance 1 ethernet
  encapsulation default
  xconnect 72.15.50.252 999 encapsulation mpls
 !
end

lab01.asr920#sh run int gi0/0/23
Building configuration...

Current configuration : 320 bytes
!
interface GigabitEthernet0/0/23
 description Facing te0-0-26.lab02.asr920
 dampening
 mtu 9202
 ip address 10.15.51.70 255.255.255.254
 ip router isis 21949
 logging event link-status
 carrier-delay msec 0
 negotiation auto
 mpls ip
 bfd interval 300 min_rx 300 multiplier 3
 isis bfd
 service-policy output leaf
end

lab01.asr920#sh run | s policy-map
policy-map leaf
 class class-default
  queue-limit percent 100
policy-map logical
 class class-default
   service-policy leaf
policy-map root
 class class-default
   service-policy logical
lab01.asr920#

lab02.asr920#sh run int gi0/0/22
Building configuration...

Current configuration : 252 bytes
!
interface GigabitEthernet0/0/22
 description Facing Exfo
 mtu 1600
 no ip address
 negotiation auto
 no keepalive
 service-policy output leaf
 service instance 1 ethernet
  encapsulation default
  xconnect 72.15.50.251 999 encapsulation mpls
 !
end

lab02.asr920#sh run int gi0/0/23
Building configuration...

Current configuration : 320 bytes
!
interface GigabitEthernet0/0/23
 description Facing te0-0-27.lab01.asr920
 dampening
 mtu 9202
 ip address 10.15.51.71 255.255.255.254
 ip router isis 21949
 logging event link-status
 carrier-delay msec 0
 negotiation auto
 mpls ip
 bfd interval 300 min_rx 300 multiplier 3
 isis bfd
 service-policy output leaf
end

lab02.asr920#sh run | s policy-map
policy-map leaf
 class class-default
  queue-limit percent 100
policy-map logical
 class class-default
   service-policy leaf
policy-map root
 class class-default
   service-policy logical
lab02.asr920#