"pause input" on C10K connecting to Cat4507R

limtohsoon · ‎07-21-2008

Hi Sir,

A Catalyst 4507R is directly connected to a Cisco 10008's interface Gi1/1/0. "sh int gi1/1/0" on the C10K is as follows:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

GigabitEthernet1/1/0 is up, line protocol is up

Hardware is Half-height Gigabit Ethernet MAC Controller, address is 001d.a269.8d24 (bia 001d.a269.8d24)

Description: *** Connection to Catalyst 4507R ***

Internet address is 2.1.1.67/27

MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,

reliability 255/255, txload 87/255, rxload 16/255

Encapsulation ARPA, loopback not set

Keepalive set (10 sec)

Full Duplex, 1000Mbps, 1000BaseSX, Auto-negotiation, media type is SX

output flow-control is XOFF, input flow-control is XOFF

ARP type: ARPA, ARP Timeout 04:00:00

Last input 00:00:05, output 00:00:00, output hang never

Last clearing of "show interface" counters never

Input queue: 0/4096/0/0 (size/max/drops/flushes); Total output drops: 0

Interface GigabitEthernet1/1/0 queueing strategy: PXF Class-based

5 minute input rate 65216000 bits/sec, 44622 packets/sec

5 minute output rate 344833000 bits/sec, 47251 packets/sec

13753696 packets input, 827763454 bytes, 0 no buffer

Received 1240021 broadcasts (0 IP multicasts)

0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

0 watchdog, 1240015 multicast, 241410137 pause input

1510948108 packets output, 3359148857 bytes, 0 underruns

0 output errors, 0 collisions, 1 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

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I notice a high number of "pause input". Please advise what to configure on the Cat4507R's port to reduce this.

Thank you.

B.Rgds,

Lim TS

Ryan Carretta · ‎07-21-2008

Try turning off flowcontrol on the 4k interface.

limtohsoon · ‎07-21-2008

Hi Ryan,

Below is "sh int" on 4507R's interface connecting to the C10K:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

GigabitEthernet3/6 is up, line protocol is up (connected)

Hardware is Gigabit Ethernet Port, address is 0017.958b.bf2b (bia 0017.958b.bf2b)

Description: *** Connection to Cisco 10008 Gi1/1/0 ***

MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,

reliability 255/255, txload 17/255, rxload 87/255

Encapsulation ARPA, loopback not set

Keepalive set (10 sec)

Full-duplex, 1000Mb/s, link type is auto, media type is 1000BaseSX

input flow-control is on, output flow-control is on

ARP type: ARPA, ARP Timeout 04:00:00

Last input never, output never, output hang never

Last clearing of "show interface" counters never

Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue: 0/40 (size/max)

5 minute input rate 341837000 bits/sec, 46722 packets/sec

5 minute output rate 67001000 bits/sec, 44361 packets/sec

220485800313 packets input, 186924487300379 bytes, 0 no buffer

Received 611093 broadcasts (611087 multicasts)

0 runts, 0 giants, 0 throttles

77 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

0 input packets with dribble condition detected

193263552385 packets output, 36812566451171 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

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

By disabling flow control, will it cause input error counters to increase?

Thank you.

B.Rgds,

Lim TS

Ryan Carretta · ‎07-21-2008

It certainly could - it depends how much traffic you're pushing. The 4k is trying to flowcontrol the neighboring device for a reason. :) If you do see input errors, that may be an indication you're pushing too much traffic over this interface.