06-14-2002 03:15 AM - edited 03-01-2019 10:11 PM
I have a 7206VXR [ NPE-400] running 12.0(16)S8. I am experiecing rather abnormally high input queue drops on a transit network connected to one of the fast ethernets
This is affecting network performance as am seeing so many packet drops.
What could be wrong ?
Here is a sample output captured after 7 minutes of doing clear counters on the interface
gw1#show int fa4/1
FastEthernet4/1 is up, line protocol is up
Hardware is i82543 (Livengood), address is 0008.e260.0871 (bia 0008.e260.0871)
Internet address is 195.xx.xx.xx/26
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec, rely 255/255, load 5/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 100Mb/s, 100BaseTX/FX
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 00:07:12
Queueing strategy: fifo
Output queue 0/40, 0 drops; input queue 0/75, 21754 drops
5 minute input rate 2966000 bits/sec, 709 packets/sec
5 minute output rate 2192000 bits/sec, 1089 packets/sec
297622 packets input, 158935506 bytes
Received 0 broadcasts, 0 runts, 0 giants, 36473 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 0 multicast
0 input packets with dribble condition detected
452773 packets output, 110146983 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier
06-14-2002 04:01 AM
What is the configuration of the interface? Is Fast-Swiching or CEF enabled. Is the router having to process switch every packet for some reason.
Post the configuration of the interface.
A simple way to correct *may* be to increase the size of the input queue in the case of bursty traffic like IPX.
06-14-2002 05:18 AM
below is the interface config, increase of the input queue depth , doesnt help either
interface FastEthernet4/1
ip address 195.202.69.60 255.255.255.192
no ip directed-broadcast
speed 100
full-duplex
no cdp enable
!
gw1#show int fa4/1
FastEthernet4/1 is up, line protocol is up
Hardware is i82543 (Livengood), address is 0008.e260.0871 (bia 0008.e260.0871)
Internet address is 195.xx.xx.xx/26
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec, rely 255/255, load 7/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 100Mb/s, 100BaseTX/FX
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 00:00:21
Queueing strategy: fifo
Output queue 0/40, 0 drops; input queue 0/200, 1732 drops
5 minute input rate 2461000 bits/sec, 747 packets/sec
5 minute output rate 2930000 bits/sec, 1258 packets/sec
16405 packets input, 6879085 bytes
Received 0 broadcasts, 0 runts, 0 giants, 2739 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 0 multicast
0 input packets with dribble condition detected
27774 packets output, 7826858 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 output buffer failures, 0 output buffers swapped out
06-14-2002 05:25 AM
You might try changing your queuing from fifo to weighted-fair.
That has helped solve some packet drops for me.
Gordon
06-14-2002 05:56 AM
Still getting the drops
gw1#show int fa4/1
FastEthernet4/1 is up, line protocol is up
Hardware is i82543 (Livengood), address is 0008.e260.0871 (bia 0008.e260.0871)
Internet address is 195.xx.xx.xx/26
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec, rely 255/255, load 6/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 100Mb/s, 100BaseTX/FX
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 00:01:53
Input queue: 0/75/4288 (size/max/drops); Total output drops: 0
Queueing strategy: weighted fair
Output queue: 0/1000/64/0 (size/max total/threshold/drops)
Conversations 0/2/256 (active/max active/max total)
Reserved Conversations 0/0 (allocated/max allocated)
5 minute input rate 2808000 bits/sec, 754 packets/sec
5 minute output rate 2581000 bits/sec, 1160 packets/sec
69379 packets input, 31527226 bytes
Received 0 broadcasts, 0 runts, 0 giants, 7158 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 0 multicast
0 input packets with dribble condition detected
111324 packets output, 29039822 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 output buffer failures, 0 output buffers swapped out
06-17-2002 05:25 AM
Hi.
I don't think that changing the queuing will solve input queue drops!
What's your CPU load?
Rgds.
NM
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