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[Tecmessa]

I have a problem with overruns on my Portchannel. Does anybody has an idea from what this can come?

I had pauseoutputs on another interface, and since i activated Flowcontrol, its good.


Hardware is a cisco 6506 with sup70 and a 6548-GE-TX Module

here is the interface Config

xxxxxxxxxxxxx#sh run int port 10

interface Port-channel10
description PORTCHANNEL VMWARE-xxxxxxxxxxxxx
switchport
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 2-14,30
switchport mode trunk
no ip address
end

xxxxxxxxxxxxx#sh run int gig 3/41

interface GigabitEthernet3/41
description ETHERCHANNEL 10
switchport
switchport trunk allowed vlan 2-14,30
switchport mode trunk
no ip address
speed 1000
duplex full
flowcontrol receive desired
flowcontrol send off
channel-group 10 mode on
end

xxxxxxxxxxxxx#sh run int gig 3/42

interface GigabitEthernet3/42
description ETHERCHANNEL 10
switchport
switchport trunk allowed vlan 2-14,30
switchport mode trunk
no ip address
speed 1000
duplex full
flowcontrol receive desired
flowcontrol send off
channel-group 10 mode on
end


xxxxxxxxxxxxx#sh int port-channel 10
Port-channel10 is up, line protocol is up (connected)
Hardware is EtherChannel, address is 0014.a9df.0c39 (bia 0014.a9df.0c39)
Description: PORTCHANNEL VMWARE-xxxxxxxxxxxxx
MTU 1500 bytes, BW 2000000 Kbit, DLY 10 usec,
reliability 255/255, txload 0/255, rxload 0/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 1000Mb/s
input flow-control is on, output flow-control is off
Members in this channel: Gi3/41 Gi3/42
ARP type: ARPA, ARP Timeout 04:00:00
Last input never, output never, output hang never
Last clearing of "show interface" counters 1d04h
Input queue: 0/2000/25697/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 5626000 bits/sec, 832 packets/sec
5 minute output rate 5148000 bits/sec, 776 packets/sec
51669839 packets input, 49653302530 bytes, 0 no buffer
Received 133886 broadcasts (0 multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 25697 overrun, 0 ignored
0 watchdog, 0 multicast, 0 pause input
0 input packets with dribble condition detected
34009711 packets output, 23313398961 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 PAUSE output
0 output buffer failures, 0 output buffers swapped out

xxxxxxxxxxxxx#sh int gig 3/41
GigabitEthernet3/41 is up, line protocol is up (connected)
Hardware is C6k 1000Mb 802.3, address is 0014.a9df.0c38 (bia 0014.a9df.0c3
Description: ETHERCHANNEL 10
MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 1000Mb/s
input flow-control is on, output flow-control is off
Clock mode is auto
ARP type: ARPA, ARP Timeout 04:00:00
Last input never, output 00:00:25, output hang never
Last clearing of "show interface" counters 1d04h
Input queue: 0/2000/17862/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 3445000 bits/sec, 513 packets/sec
5 minute output rate 874000 bits/sec, 305 packets/sec
22934785 packets input, 18998498343 bytes, 0 no buffer
Received 55652 broadcasts (0 multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 8931 overrun, 0 ignored
0 watchdog, 0 multicast, 0 pause input
0 input packets with dribble condition detected
17845661 packets output, 8841576974 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 PAUSE output
0 output buffer failures, 0 output buffers swapped out
xxxxxxxxxxxxx#sh int gig 3/42
GigabitEthernet3/42 is up, line protocol is up (connected)
Hardware is C6k 1000Mb 802.3, address is 0014.a9df.0c39 (bia 0014.a9df.0c39)
Description: ETHERCHANNEL 10
MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 1000Mb/s
input flow-control is on, output flow-control is off
Clock mode is auto
ARP type: ARPA, ARP Timeout 04:00:00
Last input never, output 00:00:27, output hang never
Last clearing of "show interface" counters 1d04h
Input queue: 0/2000/33532/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 1224000 bits/sec, 174 packets/sec
5 minute output rate 2900000 bits/sec, 319 packets/sec
28720979 packets input, 30610763636 bytes, 0 no buffer
Received 78564 broadcasts (0 multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 16766 overrun, 0 ignored
0 watchdog, 0 multicast, 0 pause input
0 input packets with dribble condition detected
16156926 packets output, 14431725476 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 PAUSE output
0 output buffer failures, 0 output buffers swapped out


Thanks

Bernhard

[eusromo]

Noticed that you are using a 6548 GE module and have two consecutive ports on this module configured for your portchannel. Keep in mind that the 6548 module has a single ASIC for each 8 consecutive ports. Each ASIC has only a one gig pipe to the backplane. As such, a portchannel configured on two consecutive ports within an 8 port grouping still has an effective bandwidth of 1 gig. You'll have to space the interfaces that comprise your portchannel at least every other 8 ports i.e. port 1, 9, 17, etc.