11-17-2021 03:23 AM
Hi,
Our management station gives an notification about high output drops on interfaces.
After some debugging I have found the following information but am unsure what to make of it. And if this is an actual issue or just microbust drops.
This is on a Cat 9400 switch.
high amount of OQD on interface 1/0/22:
en02-abh022#show int summary *: interface is up IHQ: pkts in input hold queue IQD: pkts dropped from input queue OHQ: pkts in output hold queue OQD: pkts dropped from output queue RXBS: rx rate (bits/sec) RXPS: rx rate (pkts/sec) TXBS: tx rate (bits/sec) TXPS: tx rate (pkts/sec) TRTL: throttle count Interface IHQ IQD OHQ OQD RXBS RXPS TXBS TXPS TRTL ----------------------------------------------------------------------------------------------------------------- GigabitEthernet1/0/18 0 0 0 0 0 0 0 0 0 GigabitEthernet1/0/19 0 0 0 184456 0 0 0 0 0 * GigabitEthernet1/0/20 0 0 0 77949 213000 46 154000 44 0 GigabitEthernet1/0/21 0 0 0 2701 0 0 0 0 0 * GigabitEthernet1/0/22 0 0 0 86482 68000 13 313000 39 0
No output errors on the interface:
#show interface GigabitEthernet1/0/22 GigabitEthernet1/0/22 is up, line protocol is up (connected) Hardware is Gigabit Ethernet, address is 5c71.0d16.97f5 (bia 5c71.0d16.97f5) MTU 9100 bytes, BW 1000000 Kbit/sec, DLY 10 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec) Full-duplex, 1000Mb/s, media type is 10/100/1000BaseTX input flow-control is off, output flow-control is unsupported Auto-MDIX on (operational: on) ARP type: ARPA, ARP Timeout 04:00:00 Last input 00:01:28, output 00:00:01, output hang never Last clearing of "show interface" counters 2w5d Input queue: 0/375/0/0 (size/max/drops/flushes); Total output drops: 86494 Queueing strategy: Class-based queueing Output queue: 0/40 (size/max) 5 minute input rate 93000 bits/sec, 33 packets/sec 5 minute output rate 702000 bits/sec, 80 packets/sec 7541536 packets input, 4175452690 bytes, 0 no buffer Received 13989 broadcasts (11168 multicasts) 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 watchdog, 11168 multicast, 0 pause input 0 input packets with dribble condition detected 13028188 packets output, 10316245654 bytes, 0 underruns Output 434509 broadcasts (0 multicasts) 0 output errors, 0 collisions, 2 interface resets 0 unknown protocol drops 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier, 0 pause output 0 output buffer failures, 0 output buffers swapped out
The service policy outgoing is showing default class drops:
#show policy-map interface GigabitEthernet1/0/22 GigabitEthernet1/0/22 Service-policy output: ACCESS_OUT <output omitted> Class-map: BULK-DATA (match-any) 0 packets Match: dscp af13 (14) Queueing (total drops) 0 (bytes output) 0 bandwidth remaining 5% Class-map: class-default (match-any) 0 packets Match: any Queueing (total drops) 131929956 (bytes output) 9918062185 bandwidth remaining 20%
taildropping:
#show platform hard fed active qos queue stats interface GigabitEthernet1/0/22 ---------------------------------------------------------------------------------------------- AQM Global counters GlobalHardLimit: 9500 | GlobalHardBufCount: 0 GlobalSoftLimit: 35476 | GlobalSoftBufCount: 0 ---------------------------------------------------------------------------------------------- High Watermark Soft Buffers: Port Monitor Disabled ---------------------------------------------------------------------------------------------- Asic:0 Core:0 DATA Port:42 Hardware Enqueue Counters ---------------------------------------------------------------------------------------------- Q Buffers Enqueue-TH0 Enqueue-TH1 Enqueue-TH2 Qpolicer (Count) (Bytes) (Bytes) (Bytes) (Bytes) -- ------- -------------------- -------------------- -------------------- -------------------- 0 0 0 316867966 12289408 0 1 0 0 0 14246585 0 2 0 0 0 13536 0 3 0 0 0 8001743 0 4 0 0 0 0 0 5 0 0 0 6732895248 0 6 0 0 0 0 0 7 0 0 0 0 0 Asic:0 Core:0 DATA Port:42 Hardware Drop Counters -------------------------------------------------------------------------------------------------------------------------------- Q Drop-TH0 Drop-TH1 Drop-TH2 SBufDrop QebDrop QpolicerDrop (Bytes) (Bytes) (Bytes) (Bytes) (Bytes) (Bytes) -- -------------------- -------------------- -------------------- -------------------- -------------------- -------------------- 0 0 0 0 0 0 0 1 0 0 0 0 0 0 2 0 0 0 0 0 0 3 0 0 0 0 0 0 4 0 0 0 0 0 0 5 0 0 84117614 0 0 0 6 0 0 0 0 0 0 7 0 0 0 0 0 0
How do I proceed in the tshoot from here?
11-17-2021 03:41 AM
Hello,
your first action to take with output drops would be to configure:
qos queue-softmax-multiplier 1200
in global configuration mode. Clear the counters and check if the output drops decrease...
11-17-2021 03:43 AM - edited 11-17-2021 03:44 AM
This is confusing me, you're saying your class-default is dropping but I'm seeing class 5 being dropped. Just commenting so I can keep an eye on the thread and learn something.
11-17-2021 06:40 AM
As far as I can see most traffic is added to queue 5:
#show platform hardware fed active qos queue label2qmap qmap-egress-data interface gi 1/0/22 Egress DATA Queue Mapping - Asic/Core/Port: 0/0/42 =============================================================================== Label Q Threshold VQ | Label Q Threshold VQ | Label Q Threshold VQ ===== === ========= === | ===== === ========= === | ===== === ========= === 0 5 2 2 1 5 2 2 2 5 2 2 3 5 2 2 4 5 2 2 5 5 2 2 6 5 2 2 7 5 2 2 8 5 2 2 9 5 2 2 10 5 2 2 11 5 2 2 12 5 2 2 13 5 2 2 14 5 2 2 15 4 2 2 16 5 2 2 17 5 2 2 18 5 2 2 19 3 2 2 20 5 2 2 21 5 2 2 22 5 2 2 23 5 2 2 24 5 2 2 25 2 2 2 26 5 2 2 27 2 2 2 28 5 2 2 29 2 2 2 30 5 2 2 31 2 2 2 32 5 2 2 33 1 2 2 34 5 2 2 35 1 2 2 36 5 2 2 37 1 2 2 38 5 2 2 39 1 2 2 40 5 2 2 41 5 2 2 42 5 2 2 43 5 2 2 44 5 2 2 45 5 2 2 46 5 2 2 47 0 1 2 48 5 2 2 49 5 2 2 50 5 2 2 51 5 2 2 52 5 2 2 53 5 2 2 54 5 2 2 55 5 2 2 56 5 2 2 57 5 2 2 58 5 2 2 59 5 2 2 60 5 2 2 61 5 2 2 62 5 2 2 63 5 2 2 64 5 2 2
https://people.ucsc.edu/~warner/Bufs/9000-QoS-and-Queuing.pdf
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