[c-nsp] Packet drops on ME3600X policy-map
Lukas Tribus
luky-37 at hotmail.com
Tue Oct 21 13:54:27 EDT 2014
See:
http://www.gossamer-threads.com/lists/cisco/nsp/169280
> Date: Tue, 21 Oct 2014 13:23:04 -0400
> From: lobotiger at gmail.com
> To: cisco-nsp at puck.nether.net
> Subject: [c-nsp] Packet drops on ME3600X policy-map
>
> Hey everyone, I'm trying to figure this one out and I'm banging my head
> on it. I've got a relatively simple child-parent policy-map configured
> on a port. The shaping is set to 400M but with traffic at less than
> 300M I'm seeing consistent drop rates specifically in the class-default
> section of the child policy.
>
> This is the configuration:
>
> policy-map BACKBONE_OUT_QOS
> class RT_QOS_GROUP
> priority
> set mpls experimental topmost 5
> set cos 5
> class CT_QOS_GROUP
> bandwidth remaining percent 5
> set mpls experimental topmost 6
> set cos 6
> class FC2_QOS_GROUP
> bandwidth remaining percent 10
> set mpls experimental topmost 4
> set cos 4
> class FC_QOS_GROUP
> bandwidth remaining percent 50
> set mpls experimental topmost 3
> set cos 3
> class BC_QOS_GROUP
> bandwidth remaining percent 20
> set mpls experimental topmost 2
> set cos 2
> class SC_QOS_GROUP
> set mpls experimental topmost 1
> set cos 1
> class class-default
> set mpls experimental topmost 0
> set cos 0
> !
> policy-map BACKBONE_OUT_400M
> class class-default
> shape average 400000000
> service-policy BACKBONE_OUT_QOS
> !
>
> The class-maps are matching their respective qos-group markings.
>
> And it's applied to the physical interface:
>
> interface GigabitEthernet0/23
> switchport trunk allowed vlan blah
> switchport mode trunk
> mtu 9800
> load-interval 30
> service-policy input BACKBONE_IN
> service-policy output BACKBONE_OUT_400M
> end
>
> The output of a show command is as follows:
>
> #sh policy-map int g0/23 output
> GigabitEthernet0/23
>
> Service-policy output: BACKBONE_OUT_400M
>
> Class-map: class-default (match-any)
> 13340674 packets, 12526672443 bytes
> 30 second offered rate 293739000 bps, drop rate 432000 bps
> Match: any
> Traffic Shaping
> Average Rate Traffic Shaping
> Shape 400000 (kbps)
> Output Queue:
> Default Queue-limit 49152 bytes
> Tail Packets Drop: 16218
> Tail Bytes Drop: 15933830
>
> Service-policy : BACKBONE_OUT_QOS
>
> Class-map: RT_QOS_GROUP (match-any)
> 0 packets, 0 bytes
> 30 second offered rate 0000 bps, drop rate 0000 bps
> Match: qos-group 5
> Strict Priority
> set mpls exp topmost 5
> set cos 5
> Queue-limit current-queue-depth 0 bytes
> Output Queue:
> Default Queue-limit 49152 bytes
> Tail Packets Drop: 0
> Tail Bytes Drop: 0
>
> Class-map: CT_QOS_GROUP (match-any)
> 358 packets, 98876 bytes
> 30 second offered rate 0000 bps, drop rate 0000 bps
> Match: qos-group 6
> Bandwidth Remaining 5 (percent)
> set mpls exp topmost 6
> set cos 6
> Queue-limit current-queue-depth 0 bytes
> Output Queue:
> Default Queue-limit 49152 bytes
> Tail Packets Drop: 0
> Tail Bytes Drop: 0
>
> Class-map: FC2_QOS_GROUP (match-any)
> 0 packets, 0 bytes
> 30 second offered rate 0000 bps, drop rate 0000 bps
> Match: qos-group 4
> Bandwidth Remaining 10 (percent)
> set mpls exp topmost 4
> set cos 4
> Queue-limit current-queue-depth 0 bytes
> Output Queue:
> Default Queue-limit 49152 bytes
> Tail Packets Drop: 0
> Tail Bytes Drop: 0
>
> Class-map: FC_QOS_GROUP (match-any)
> 0 packets, 0 bytes
> 30 second offered rate 0000 bps, drop rate 0000 bps
> Match: qos-group 3
> Bandwidth Remaining 50 (percent)
> set mpls exp topmost 3
> set cos 3
> Queue-limit current-queue-depth 0 bytes
> Output Queue:
> Default Queue-limit 49152 bytes
> Tail Packets Drop: 0
> Tail Bytes Drop: 0
>
> Class-map: BC_QOS_GROUP (match-any)
> 0 packets, 0 bytes
> 30 second offered rate 0000 bps, drop rate 0000 bps
> Match: qos-group 2
> Bandwidth Remaining 20 (percent)
> set mpls exp topmost 2
> set cos 2
> Queue-limit current-queue-depth 0 bytes
> Output Queue:
> Default Queue-limit 49152 bytes
> Tail Packets Drop: 0
> Tail Bytes Drop: 0
>
> Class-map: SC_QOS_GROUP (match-any)
> 0 packets, 0 bytes
> 30 second offered rate 0000 bps, drop rate 0000 bps
> Match: qos-group 1
> set mpls exp topmost 1
> set cos 1
> Queue-limit current-queue-depth 0 bytes
> Output Queue:
> Default Queue-limit 49152 bytes
> Tail Packets Drop: 0
> Tail Bytes Drop: 0
>
> Class-map: class-default (match-any)
> 13340316 packets, 12526573567 bytes
> 30 second offered rate 293737000 bps, drop rate 432000 bps
> Match: any
> set mpls exp topmost 0
> set cos 0
> Queue-limit current-queue-depth 0 bytes
> Output Queue:
> Default Queue-limit 49152 bytes
> Tail Packets Drop: 16218
> Tail Bytes Drop: 15933830
>
> The number of tail drops is pretty close to the output drops shown on
> the interface itself too:
>
> rocpe06#sh int g0/23
> GigabitEthernet0/23 is up, line protocol is up (connected)
> <snip>
> MTU 9800 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
> reliability 255/255, txload 74/255, rxload 26/255
> Encapsulation ARPA, loopback not set
> Keepalive not set
> Full-duplex, 1000Mb/s, media type is SX
> input flow-control is off, output 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 00:05:40
> Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 15365
> Queueing strategy: fifo
> Output queue: 0/40 (size/max)
> 30 second input rate 105779000 bits/sec, 35781 packets/sec
> 30 second output rate 293211000 bits/sec, 38999 packets/sec
> 11830165 packets input, 4313484039 bytes, 0 no buffer
> Received 15400 broadcasts (6262 multicasts)
> 0 runts, 0 giants, 0 throttles
> 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
> 0 watchdog, 6262 multicast, 0 pause input
> 0 input packets with dribble condition detected
> 13145027 packets output, 12329007673 bytes, 0 underruns
> 0 output errors, 0 collisions, 0 interface resets
> 12 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
> !
>
> Any thoughts on whether it's the policy-map that needs tweaking somehow
> or if it's some other issue? All of the traffic that is being dropped is
> traffic that is general internet but some folks have started to notice
> some packet loss.
>
> Any input would be appreciated.
>
> Jose
>
> _______________________________________________
> cisco-nsp mailing list cisco-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/
More information about the cisco-nsp
mailing list