10-29-2010 03:47 PM - edited 03-06-2019 01:48 PM
Hi,
Am trying to determine why we are seeing outpiut drops on some of our interfaces connected to servers with 100Mb NIC's.
6509 with WS-X6748-GE-TX
Example,
GigabitEthernet1/3/25 is up, line protocol is up (connected)
Hardware is C6k 1000Mb 802.3, address is 0000.0000.0018 (bia 0021.d8e7.1948)
Description: SRV-VAN-KDCM1 PRIMARY A6-21
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 100Mb/s, media type is 10/100/1000BaseT
input flow-control is off, output flow-control is off
Clock mode is auto
ARP type: ARPA, ARP Timeout 04:00:00
Last input never, output never, output hang never
Last clearing of "show interface" counters 00:24:40
Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 5895
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 12000 bits/sec, 2 packets/sec
0 packets input, 0 bytes, 0 no buffer
Received 0 broadcasts (0 multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 0 multicast, 0 pause input
0 input packets with dribble condition detected
11497 packets output, 10231823 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
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
Interface GigabitEthernet1/3/25 queueing strategy: Weighted Round-Robin
Port QoS is enabled
Trust boundary disabled
Port is untrusted
Extend trust state: not trusted [COS = 0]
Default COS is 0
Queueing Mode In Tx direction: mode-cos
Transmit queues [type = 1p3q8t]:
Queue Id Scheduling Num of thresholds
-----------------------------------------
01 WRR 08
02 WRR 08
03 WRR 08
04 Priority 01
WRR bandwidth ratios: 47[queue 1] 42[queue 2] 11[queue 3]
queue-limit ratios: 55[queue 1] 25[queue 2] 5[queue 3] 15[Pri Queue]
queue tail-drop-thresholds
--------------------------
1 70[1] 100[2] 100[3] 100[4] 100[5] 100[6] 100[7] 100[8]
2 70[1] 100[2] 100[3] 100[4] 100[5] 100[6] 100[7] 100[8]
3 100[1] 100[2] 100[3] 100[4] 100[5] 100[6] 100[7] 100[8]
queue random-detect-min-thresholds
----------------------------------
1 80[1] 100[2] 100[3] 100[4] 100[5] 100[6] 100[7] 100[8]
2 80[1] 100[2] 100[3] 100[4] 100[5] 100[6] 100[7] 100[8]
3 60[1] 70[2] 80[3] 90[4] 100[5] 100[6] 100[7] 100[8]
queue random-detect-max-thresholds
----------------------------------
1 100[1] 100[2] 100[3] 100[4] 100[5] 100[6] 100[7] 100[8]
2 100[1] 100[2] 100[3] 100[4] 100[5] 100[6] 100[7] 100[8]
3 70[1] 80[2] 90[3] 100[4] 100[5] 100[6] 100[7] 100[8]
WRED disabled queues:
queue thresh cos-map
---------------------------------------
1 1 1
1 2
1 3
1 4
1 5
1 6
1 7
1 8
2 1 0
2 2
2 3
2 4
2 5
2 6
2 7
2 8
3 1 2
3 2 3
3 3 6
3 4 7
3 5
3 6
3 7
3 8
4 1 4 5
Queueing Mode In Rx direction: mode-cos
Receive queues [type = 1q8t]:
Queue Id Scheduling Num of thresholds
-----------------------------------------
01 WRR 08
WRR bandwidth ratios: 100[queue 1]
queue-limit ratios: 100[queue 1]
queue tail-drop-thresholds
--------------------------
1 100[1] 100[2] 100[3] 100[4] 100[5] 100[6] 100[7] 100[8]
queue thresh cos-map
---------------------------------------
1 1 0 1 2 3 4 5 6 7
1 2
1 3
1 4
1 5
1 6
1 7
1 8
Packets dropped on Transmit:
BPDU packets: 0
queue dropped [cos-map]
---------------------------------------------
1 0 [1 ]
2 5895 [0 ]
3 0 [2 3 6 7 ]
4 0 [4 5 ]
Packets dropped on Receive:
BPDU packets: 0
queue dropped [cos-map]
---------------------------------------------
1 0 [0 1 2 3 4 5 6 7 ]
interface GigabitEthernet1/3/25
description SRV-VAN-KDCM1 PRIMARY A6-21
switchport
switchport access vlan 47
switchport mode access
no logging event link-status
wrr-queue bandwidth 47 42 11
wrr-queue queue-limit 55 25 5
wrr-queue random-detect min-threshold 1 80 100 100 100 100 100 100 100
wrr-queue random-detect min-threshold 2 80 100 100 100 100 100 100 100
wrr-queue random-detect min-threshold 3 60 70 80 90 100 100 100 100
wrr-queue random-detect max-threshold 1 100 100 100 100 100 100 100 100
wrr-queue random-detect max-threshold 2 100 100 100 100 100 100 100 100
wrr-queue random-detect max-threshold 3 70 80 90 100 100 100 100 100
wrr-queue cos-map 1 1 1
wrr-queue cos-map 2 1 0
wrr-queue cos-map 3 1 2
wrr-queue cos-map 3 2 3
wrr-queue cos-map 3 3 6
wrr-queue cos-map 3 4 7
priority-queue cos-map 1 4 5
mls qos vlan-based
no cdp enable
spanning-tree portfast edge
spanning-tree bpduguard enable
end
server traffic is very low (often <10% port speed) but seeing drops occuring every 10-20mins in Q2. Any thoughts?
11-01-2010 08:49 PM
Hi John,
Is the server traffic unmarked? COS 0 maps to Queue 2, and the number of drops in this queue correspond directly with the number of output drops on the interface.
When the output was gathered, the 5 minute output rate was quite low. Are you able to change the load-interval to 30 seconds, for a more accurate idea of traffic rate? At the 10-20min mark, we may be seeing a burst of traffic.
Also, looking at your configured queue-limit and bandwidth ratios, traffic that matches queue 1 and queue 2 should have the same profile (ie. rate, bursts), is this correct? If not, we may need to start tweaking these values.
Is the scenario the same for the other interfaces that are also seeing the drops?
Elli.
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