08-28-2014 09:20 AM - edited 03-04-2019 11:38 PM
Dear Sirs.
We have an 3845 cisco router which constantly shows discard paquets at wan interface.
there is not: saturation, CRC´s and any other anomalies at wan interface.
The IOS of the router is:
"flash:c3845-adventerprisek9-mz.151-3.T4.bin"
and the configuration of the wan interface is:
!
interface GigabitEthernet0/0
description WAN|La Molina-IBM|CD=56619|IPVPN
bandwidth 61440
ip address 10.160.1.18 255.255.255.252
ip accounting output-packets
ip flow ingress
ip flow egress
ip nat inside
ip virtual-reassembly in
ip route-cache policy
load-interval 30
duplex full
speed 100
media-type rj45
max-reserved-bandwidth 100
service-policy output IPVPN
!
The error counters is:
SITEL-CD56619_IBM#sh int gigabitEthernet 0/0
GigabitEthernet0/0 is up, line protocol is up
Hardware is BCM1125 Internal MAC, address is 001b.5358.2940 (bia 001b.5358.294
0)
Description: WAN|La Molina-IBM|CD=56619|IPVPN
Internet address is 10.160.1.18/30
MTU 1500 bytes, BW 61440 Kbit/sec, DLY 100 usec,
reliability 255/255, txload 86/255, rxload 35/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full Duplex, 100Mbps, media type is RJ45
output flow-control is XON, input flow-control is XON
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 11w3d
Input queue: 1/75/0/0 (size/max/drops/flushes); Total output drops: 2625448
Queueing strategy: Class-based queueing
Output queue: 0/1000/0 (size/max total/drops)
30 second input rate 8469000 bits/sec, 3567 packets/sec
30 second output rate 20822000 bits/sec, 4135 packets/sec
4107004053 packets input, 3102483731 bytes, 0 no buffer
Received 349220 broadcasts (0 IP multicasts)
0 runts, 0 giants, 0 throttles
4986 input errors, 0 CRC, 0 frame, 4986 overrun, 0 ignored
0 watchdog, 4025131 multicast, 0 pause input
3920684559 packets output, 3770059387 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
230444 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
SITEL-CD56619_IBM#
Would you be mind telling us if we need to change the IOS due possible bugs or maybe failure at wan interface?
Thanks allot.
08-28-2014 09:28 AM
replace patchcord
and see again
08-29-2014 11:42 AM
Hi ,
we are arrange to replace the cable, also.
thanks very much.
12-09-2014 10:03 AM
Dear Tagir.
We have changed the patch cord but the level of dropped paquet increments.
In the meanwhile we have arranged to change the model of router for the first quarter of 2015.
thank allot for your support.
Attn.
Roger
08-28-2014 11:07 AM
Disclaimer
The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.
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In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.
Posting
You don't need to saturate a link to encounter drops.
What's your service-policy look like and what are its stats?
08-28-2014 11:41 AM
Hi Joseph.
the police are:
!
class-map match-any VOZ
match access-group 100
class-map match-any DATOS
match access-group 101
class-map match-any ROUTING
description Reserva TRAFFIC BGP
match ip precedence 6 7
match mpls experimental topmost 6 7
match access-group 111
class-map match-any Best_efford
match any
!
!
policy-map IPVPN
class ROUTING
bandwidth 2048
class VOZ
priority 1024
set ip precedence 5
class class-default
set ip precedence 1
fair-queue 1024
!
SITEL-CD56619_IBM#sh policy-map interface gigabitEthernet 0/0
GigabitEthernet0/0
Service-policy output: IPVPN
queue stats for all priority classes:
queue limit 64 packets
(queue depth/total drops/no-buffer drops) 0/0/0
(pkts output/bytes output) 3201424/702931906
Class-map: ROUTING (match-any)
76696815 packets, 5312462084 bytes
30 second offered rate 10000 bps, drop rate 0 bps
Match: ip precedence 6 7
76696777 packets, 5312460032 bytes
30 second rate 10000 bps
Match: mpls experimental topmost 6 7
0 packets, 0 bytes
30 second rate 0 bps
Match: access-group 111
38 packets, 2052 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) 76696752/5407088943
bandwidth 2048 kbps
Class-map: VOZ (match-any)
3201459 packets, 702979930 bytes
30 second offered rate 1000 bps, drop rate 0 bps
Match: access-group 100
3201459 packets, 702979930 bytes
30 second rate 1000 bps
Priority: 1024 kbps, burst bytes 25600, b/w exceed drops: 35
QoS Set
precedence 5
Packets marked 3201459
Class-map: class-default (match-any)
16487541763 packets, 7549715146267 bytes
30 second offered rate 7430000 bps, drop rate 0 bps
Match: any
Queueing
queue limit 64 packets
(queue depth/total drops/no-buffer drops/flowdrops) 0/2638133/0/2638133
(pkts output/bytes output) 3875117901/7947194068295
QoS Set
precedence 1
Packets marked 16486715068
Fair-queue: per-flow queue limit 16
SITEL-CD56619_IBM#
SITEL-CD56619_IBM#
the service policy is applied at giga interface.0/0
Our provider TELEFONICA have configured the policies and have configured as best-efford the police for DATA.
At GRUPO ROMERO, all router has police: GOLDEN for VOICE (voz) and SILVER for DATA.
But for this router, they used best efford to overcome the discarded paquets which I think is wrong.
waiting your sooner answer.,
Attn.
08-29-2014 09:21 AM
Disclaimer
The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.
Liability Disclaimer
In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.
Posting
Hmm, your class-default only has a queue-limit of 64 packets, and per flow queue limit of 16 packets. Stats show as flowdrops. This is likely much too shallow for a 100 Mbps port.
08-29-2014 11:40 AM
Hi Joseph.
i appreciate your comments, but what can we do about it?
what is the best value for the queues and if we change them this will cause´ link down?
Attn.
08-31-2014 04:30 AM
Disclaimer
The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.
Liability Disclaimer
In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.
Posting
What can you do about it? Adjust queue-limit (if supported).
What's best values for queues? That's an "it depends". For a single TCP flow to be able to support path maximum bandwidth, buffers (queue-limit) needs to support BDP.
Will changing queue values take link down? Normally, no, but you might impact a some "inflight" packets.
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