09-08-2015 07:54 AM - edited 03-05-2019 02:15 AM
We have a 3945 router which is connected to our Service Provider's MPLS Cloud. There is a 100Mb circuit being delivered via Ethernet and is terminated on the Gi0/0 interface. We have the interface configured for 100Mb/full duplex. There is also QoS applied to this interface. We are noticing a large amount of dropped packets on the interface and they are continually incrementing. After looking at the policy maps we have noticed that our QoS class maps are showing packet drops and if they are added up they equal the packet drop total on the interface. When looking at our monitoring tools the interface utilization is staying around the 30% to 40% range so congestion does not appear to be an issue. What could be the cause of this issue? Could it be the default packet limit of 64 on the class maps? Should that number be increased? TAC wants us to remove QoS from the interface to see if the packet drops stop, however we don't want to take the chance on causing a possible larger issue. I have provided some of the configuration below for details. You can see the large amount of packet drops. Any suggestions would be great.
interface GigabitEthernet0/0
bandwidth 100000
ip address 192.168.X.X 255.255.255.252
no ip proxy-arp
load-interval 30
duplex full
speed 100
service-policy output outside-interface
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GigabitEthernet0/0 is up, line protocol is up
Internet address is 192.168.X.X/30
MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec,
reliability 255/255, txload 77/255, rxload 39/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full Duplex, 100Mbps, media type is RJ45
output flow-control is unsupported, input flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:00, output 00:00:00, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 6184419
Queueing strategy: Class-based queueing
Output queue: 0/1000/6183594 (size/max total/drops)
30 second input rate 15641000 bits/sec, 8770 packets/sec
30 second output rate 30238000 bits/sec, 9094 packets/sec
26022084196 packets input, 7636292617079 bytes, 0 no buffer
Received 721265 broadcasts (0 IP multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 687008 multicast, 0 pause input
29836277613 packets output, 13811234076080 bytes, 0 underruns
0 output errors, 0 collisions, 12 interface resets
687003 unknown protocol drops
0 babbles, 0 late collision, 0 deferred
10 lost carrier, 0 no carrier, 0 pause output
0 output buffer failures, 0 output buffers swapped out
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GigabitEthernet0/0
Service-policy output: outside-interface
queue stats for all priority classes:
Queueing
queue limit 64 packets
(queue depth/total drops/no-buffer drops) 0/0/0
(pkts output/bytes output) 299068133/22978214688
Class-map: VOICE_LIST (match-all)
299068136 packets, 22978214836 bytes
30 second offered rate 113000 bps, drop rate 0000 bps
Match: dscp ef (46)
Match: access-group name VOICE_PORT_LIST
Priority: 10% (10000 kbps), burst bytes 250000, b/w exceed drops: 0
Class-map: SIGNALING_LIST (match-any)
20247018 packets, 11952090960 bytes
30 second offered rate 38000 bps, drop rate 0000 bps
Match: ip dscp cs3 (24)
5500848 packets, 7190829433 bytes
30 second rate 0 bps
Match: access-group name SIGNALING_PORT_LIST
14746170 packets, 4761261527 bytes
30 second rate 38000 bps
Queueing
queue limit 64 packets
(queue depth/total drops/no-buffer drops) 0/261/0
(pkts output/bytes output) 20246748/11951729025
bandwidth 5% (5000 kbps)
Class-map: QOS_COS4_APP (match-any)
20217105080 packets, 7703169856381 bytes
30 second offered rate 14219000 bps, drop rate 3000 bps
Match: access-group name COS4_APP
20217105074 packets, 7703169886153 bytes
30 second rate 14219000 bps
Queueing
queue limit 64 packets
(queue depth/total drops/no-buffer drops) 0/1104630/0
(pkts output/bytes output) 20216000046/7702297837698
QoS Set
dscp af21
Packets marked 20217105086
bandwidth 25% (25000 kbps)
Class-map: CONTROL_DATA_LIST (match-any)
2355131 packets, 142344105 bytes
30 second offered rate 0000 bps, drop rate 0000 bps
Match: access-group name CONTROL_DATA_LIST
2355131 packets, 142344105 bytes
30 second rate 0 bps
Queueing
queue limit 64 packets
(queue depth/total drops/no-buffer drops) 0/0/0
(pkts output/bytes output) 2355131/142344105
QoS Set
dscp af22
Packets marked 2355131
bandwidth 5% (5000 kbps)
Class-map: class-default (match-any)
9304431490 packets, 6080631255346 bytes
30 second offered rate 10813000 bps, drop rate 8000 bps
Match: any
Queueing
queue limit 64 packets
(queue depth/total drops/no-buffer drops) 0/5079115/0
(pkts output/bytes output) 9299351923/6074164654781
QoS Set
dscp default
Packets marked 9301920701
bandwidth 30% (30000 kbps)
Solved! Go to Solution.