issue with EthChannel

Unanswered Question
Apr 7th, 2008
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Hi..


I configured EthChannel to aggregate two Gig interfaces between Cisco 6509 core sw and AIX server (Teaming).


Config on 6509 core as following:


On both interfaces (assume Gi7/7 & Gi7/8)


swichport

switchport access vlan 5

switchport mode access

channel-group 8 mode active


I have checked the server's NIC, it supported LACP aggregatoin type.


output ---> port-channel 8 created but ONLY interface G7/7 is member of this bundle and I found that port-channel 8A created automatically and G7/8 considered as member of this virtual bundle.


I'm trying to figure out the logic behind creation of port-channel 8A !!


any helpful comments !!!


Thx

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Istvan_Rabai Mon, 04/07/2008 - 04:10
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Hi Belal,


I believe you should specify the channel-protocol on the interface level explicitly to be lacp:


channel-protocol lacp


Try this.


Cheers:

Istvan

balsheikh Mon, 04/07/2008 - 04:24
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Hi Istvan,


I believe once I configured mode active it will select the LACP as the protocol for aggregation and I can confirm that LACP is the running protocol, I issued the command "show interface port-channel 8 eth"


it clearly shows that LACP run.

Kevin Dorrell Tue, 04/08/2008 - 05:52
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Istvan,


It is not really necessary to specify the channel-protocol because LACP is already implied in the "active" (or "passive") setting.


In fact, the channel-protocol is not a very useful command because it only serves as a sort of configuration safety lock ... a sort of "belt-and-braces" tautology. It has no direct influence on the mode of the channel.


Kevin Dorrell

Luxembourg


Istvan_Rabai Tue, 04/08/2008 - 07:41
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Hi Kevin,


Thank you for the contribution.


I want to share my experience with you:


channel-protocol pagp

channel-group 1 mode on


And the channel did not form.


So if the channel-protocol is specified, then very interestingly, the switch does not accept "on" mode.

(In "on" mode no pagp messages sent.)


I hope someone will use this info somewhere.


Cheers:

Istvan

Istvan_Rabai Tue, 04/08/2008 - 09:09
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That's good!


Thank you Edison.


Cheers:

Istvan

Edison Ortiz Mon, 04/07/2008 - 06:22
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That's very odd. I don't think is possible to have an interface with a number and a letter.


Can you post the output from typing


show version

show interface brief


and

show ether sum


Thanks


__


Edison.

balsheikh Tue, 04/08/2008 - 04:36
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Hi Edison,


believe me its possible, but the amazing thing that I found it today working fine and both interfaces shown in port-chahnnel 9 but to convince you that number and a letter is there I copied the logs and below the output:


Apr 7 14:38:46.765 KWT: %LINEPROTO-5-UPDOWN: Line protocol on Interface Port-channel9A, changed state to down


Apr 7 14:38:46.801 KWT: %LINK-3-UPDOWN: Interface GigabitEthernet7/9, changed state to down


Apr 7 14:38:46.769 KWT: %LINEPROTO-SP-5-UPDOWN: Line protocol on Interface GigabitEthernet7/9, changed state to down


Apr 7 14:38:46.769 KWT: %LINEPROTO-SP-5-UPDOWN: Line protocol on Interface GigabitEthernet7/10, changed state to down


Apr 7 14:38:46.813 KWT: %LINK-3-UPDOWN: Interface Port-channel9A, changed state to down



Apr 7 14:38:46.817 KWT: %LINK-3-UPDOWN: Interface GigabitEthernet7/10, changed state to down


Apr 7 14:38:47.001 KWT: %LINK-5-CHANGED: Interface Port-channel9A, changed state to administratively down


finally its Cisco, expect more :)



thx for support,




Kevin Dorrell Tue, 04/08/2008 - 05:55
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Strange. Never seen that before. Is it IOS or CatOS?


Sorry ... second thoughts I take that back ... it looks like IOS. Still strange though.

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