LACP Etherchannel member port STP blocking

[dbuckley77]

Should a port that is a member of an LACP etherchannel ever be in STP blocking mode?

[Madhukrishnan Gopinathan Nair]

Once you add an interface to port-channel, that member port does not participate in lacp until it removes from channel. So once you add a channel if you look at spanning tree you will see only Portchannel interface in spanning tree.

Depending on your configuration a port-channel itself can be blokcing if you have redundant port-channels. Else not likely.

Check using sh spanning-tree vlan <>

Hope this helps 

Thanks,

Madhu

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[Madhukrishnan Gopinathan Nair]

Typo...i meant member port does not participate in STP , not lacp:)

[Madhukrishnan Gopinathan Nair]

Reason behind it, you are logically uniting 2 link to act as one...

Ultimate goal of Port-cahnnel is to gain more bandwidth by ovecoming spanning tree redundant blocking links :)

[dbuckley77]

So I have LACP etherchannel configured with two ports at each end between two Nexus 3000.  I noticed that only one port is up on one end because the  other port does not have the channel-group 5 mode active command on it but it has the flow control receive on command so I cannot add this port to the port-channel.  How do I disable the flow control receive on for his port?

[Madhukrishnan Gopinathan Nair]

I have not worked on Nexus 3000 but try the below to see if it helps under the port.

no flowcontrol receive on

[dbuckley77]

I tried that and it won't work.

If I get into config on that interface and do a ? it won't even show flow in the list of commands.

[Madhukrishnan Gopinathan Nair]

Just try typing it in and enter.

no flowcontrol receive on

[Madhukrishnan Gopinathan Nair]

this is what i see

http://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus3548/sw/qos/602_A1_1/b_N3548_QoS_Config_602_A11/b_N3548_QoS_Config_602_A11_chapter_0100.html#concept_CB2A1C7F021449FCB8E49BF0FC16F7D7

[dbuckley77]

I tried typing it in even though it was not in the help list so what I did was configure another port to be in that port-channel and moved the cable over to that port.

Now when I do a sh port-channel summary I see (SU) on the port-channel interface and (P) on the ethernet interfaces.  This means that everything is working properly, correct?

[Madhukrishnan Gopinathan Nair]

SU means it is up in Bundle in Layer 2. So I think all is well.

Quite not sure of P in interface..again my lack of knowledge on platform. But I assume all is good since port channel is in SU.

Hope this helps and do remember to rate any useful posts if any.

Thanks,

Madhu