Problems with etherchannels

lcuchisanmillan · ‎07-06-2010

Hello all,

We are having a cosmetic problem with a etherchannel connecting 2 Cisco 6500, via 2 gigabit interfaces in each side. The link is okay and is it working fine, is more a cosmetic problem. The devices are directly connected and when we do a "show interfaces" we get the following:

SWITCH 1 SWITCH 2

_ Port channel X _ Port channel Y

4459995 packets input 5038640 packets input

2396802 packets output 9470937 packets output

_ Interface Giga X/1 _ Interface Giga Y/1

3980467 packets input 1930376 packets input

1938976 packets output 3963757 packets output

_ Interface Giga X/2 _ Interface Giga Y/2

7173942 packets input 3989266 packets input

3989205 packets output 7172782 packets output

As you can see there the packet counters in the interfaces that form the Etherchannel are alright:

The total of the input packets in SWITCH 1 interface X/1 and X/2 are similar to the total of the output packets in SWITCH 2 interface Y/1 and Y/2 and the total of the output packets in SWITCH 1 interface X/1 and X/2 are similar to the total of the input packets in SWITCH 2 interface Y/1 and Y/2.

The problem is with Port-channel counters:

_ First, the input/output packets is not the total of its interfaces input/output packets

_ Second one, input/putput packets of Port-channel X of SWITCH 1 does not coincide with output/input packets of Port-channel Y of SWITCH 2

Does anyone know if this is normal and why?

Thank you very much

danrya · ‎07-06-2010

Are there drops or errors on the EC's? Can you attach the "show interface po x/x" and "show interface po x/x summary"?

Maybe that will shed some light on the issue.

lcuchisanmillan · ‎07-07-2010

Hello danrya,

We do not see any drops in the etherchannels, here you have the outputs:

SWITCH 1

#sh int PoX

Port-channelY is up, line protocol is up (connected)
Hardware is EtherChannel, address is XXXXXXXXXXXXXXX
MTU 1500 bytes, BW 2000000 Kbit, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 11/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 1000Mb/s
input flow-control is off, output flow-control is off
Members in this channel: Gi7/1 Gi7/2
ARP type: ARPA, ARP Timeout 04:00:00
Last input never, output never, output hang never
Last clearing of "show interface" counters 1w5d
Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
30 second input rate 87552000 bits/sec, 18261 packets/sec
30 second output rate 5623000 bits/sec, 9234 packets/sec
     11565866639 packets input, 7794362603329 bytes, 0 no buffer
     Received 3322152 broadcasts (2475613 multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 0 multicast, 0 pause input
     0 input packets with dribble condition detected
     9549561617 packets output, 4454444531302 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

#sh int PoX summ

*: interface is up
IHQ: pkts in input hold queue     IQD: pkts dropped from input queue
OHQ: pkts in output hold queue    OQD: pkts dropped from output queue
RXBS: rx rate (bits/sec)          RXPS: rx rate (pkts/sec)
TXBS: tx rate (bits/sec)          TXPS: tx rate (pkts/sec)
TRTL: throttle count

Interface               IHQ   IQD OHQ   OQD RXBS RXPS TXBS TXPS TRTL
-------------------------------------------------------------------------
* Port-channelX           0     0    0     0 65495000 13626 4199000 6882    0
NOTE:No separate counters are maintained for subinterfaces
     Hence Details of subinterface are not shown

SWITCH 2

#sh int PoY

Port-channelY is up, line protocol is up (connected)
Hardware is EtherChannel, address is YYYYYYYYYYYYYYY
MTU 1500 bytes, BW 2000000 Kbit, DLY 10 usec,
     reliability 255/255, txload 9/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 1000Mb/s
input flow-control is off, output flow-control is off
Members in this channel: Gi7/1 Gi7/2
ARP type: ARPA, ARP Timeout 04:00:00
Last input never, output never, output hang never
Last clearing of "show interface" counters 1w5d
Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
30 second input rate 4932000 bits/sec, 8081 packets/sec
30 second output rate 76591000 bits/sec, 15967 packets/sec
     15803657188 packets input, 7293008709881 bytes, 0 no buffer
     Received 43062517 broadcasts (13063671 multicasts)
     0 runts, 0 giants, 0 throttles
     1 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 0 multicast, 0 pause input
     0 input packets with dribble condition detected
     19179225172 packets output, 12941767311772 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

#sh int PoY summ

*: interface is up
IHQ: pkts in input hold queue     IQD: pkts dropped from input queue
OHQ: pkts in output hold queue    OQD: pkts dropped from output queue
RXBS: rx rate (bits/sec)          RXPS: rx rate (pkts/sec)
TXBS: tx rate (bits/sec)          TXPS: tx rate (pkts/sec)
TRTL: throttle count

Interface               IHQ   IQD OHQ   OQD RXBS RXPS TXBS TXPS TRTL
-------------------------------------------------------------------------
* Port-channelY           0     0    0     0 5105000 8541 81279000 16919    0
NOTE:No separate counters are maintained for subinterfaces
     Hence Details of subinterface are not shown