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Port-channel down but duplicate interface created with "B" up

Hi all

I have created 1 new port channels on a 6509 connected to ASR1002

Below the show about the Port-Channel

Port-channel9             unassigned      YES unset  down                  down     

Port-channel9B            unassigned      YES unset  up                    up

Can someone explain what this is any why it is occurring?

Thanks

Marco

4 REPLIES
Cisco Employee

Re: Port-channel down but duplicate interface created with "B" u

Hi Marco,

Is that on the 6500 side or ASR side? Do a show interface po3B, and show run int po3B.

HTH
Lei Tian

Sent from Cisco Technical Support iPhone App

New Member

Re: Port-channel down but duplicate interface created with "B" u

Hi Lei

is on 6500 side.

c6509e-00#sh int po9B

Port-channel9B is up, line protocol is up (connected)

  Hardware is EtherChannel, address is 001d.456d.ca59 (bia 001d.456d.ca59)

  MTU 1500 bytes, BW 2000000 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, media type is unknown

  input flow-control is off, output flow-control is off

  Members in this channel: Gi8/10 Gi8/36

  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 1076000 bits/sec, 882 packets/sec

  5 minute output rate 8490000 bits/sec, 1399 packets/sec

     11961422 packets input, 3534458687 bytes, 0 no buffer

     Received 6087 broadcasts (6077 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

     18223769 packets output, 13177086156 bytes, 0 underruns

     0 output errors, 0 collisions, 2 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

c6509e-00#sh run int po9

Building configuration...

Current configuration : 135 bytes

!

interface Port-channel9

switchport

switchport access vlan 181

switchport mode access

end

thanks

Marco

Cisco Employee

Re: Port-channel down but duplicate interface created with "B" u

Hi Marco,

Do search 'spawn port channel' on google, and you should find similar cases. Basically, it was caused by mis-configuration on port channel.

HTH,
Lei Tian

Sent from Cisco Technical Support iPhone App

Re: Port-channel down but duplicate interface created with "B" u

Hi Marco,

this is called a "secondary aggregator port".

Like Lei has already stated, it's typically caused by misconfiguration between the member-ports.

Here you can find a similar discussion, I think it will provide you with all the information:

https://supportforums.cisco.com/message/3352041

Best regards

Rolf

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