Switchport configuration help - link aggregation

[cisco_fednav]

hello appreciate any help from the cisco gurus out there,

i am trying to setup two ports on a stack of 3750 switches via link aggregation using LACP. The config currently in place is:

interface Port-channel6
 description backupmedia
 switchport trunk encapsulation dot1q
 switchport mode trunk
 switchport nonegotiate
 spanning-tree portfast

interface GigabitEthernet2/0/12
 description backupmedia
 switchport trunk encapsulation dot1q
 switchport mode trunk
 switchport nonegotiate
 channel-group 6 mode on

interface GigabitEthernet3/0/4
 description backupmedia
 switchport trunk encapsulation dot1q
 switchport mode trunk
 switchport nonegotiate
 channel-group 6 mode on

At the other end I have a set of broadcom interfaces where as soon as we attempt the teaming the communication gets lost and it brings our fileserver to a halt which happens to be on the same stack but on another etherchannel with Mode On (No LACP).

I'm I missing something? Should LACP be activated globally?

I think each port should be setup this way but im not entirely sure.

interface GigabitEthernet2/0/12
 description backupmedia
 switchport trunk encapsulation dot1q
 switchport mode trunk
 channel-protocol lacp
 channel-group 6 mode active

Thanks in advance,

Laurent

lg@fednav.com

[paul driver]

Hello

Etherchannels require the same configuration on either ends of the connection

be it dynamically learning via lacp/pagp or manual

(active/active active/passive auto/auto auto/desirable on/on etc)

But either side needs to be able to support whatever you use

Lasty for L2 port channels the way I would create them is:

1) default the physical interfaces /shut them down

2) then on these interfaces apply the channel-group ( which will automatically creates the virtual port channel interface)

3) Then configure only the port channel as trunks or access ports etc - This config will automatically get installed on the physical interfaces

4) enable the physical interfaces

res

paul

[cisco_fednav]

Hello Paul,

Thanks for your quick answer.

Can a channel group setup in LACP mode conflict with a channel group setup in "On" mode on the same stack of switches?

Thanks again

Laurent

[paul driver]

Hello

If the devices are interconnected YES - as the etherchannel wont come up, but if you are asking about certain etherchannels having link aggregation or not on different ports attaching to their own relating devices then NO -

They shouldn’t impede on each other

res
Paul

[Masoud Pourshabanian]

Hello,

At first, try to download the latest BACS on your sever. It is very important.If you choose LACP as team type, mode active should be set on the switch. If you choose Link Aggregation (802.3ad) on the server side, mode passive on switch should be set.

Please get back with result.

Masoud

[cisco_fednav]

I managed to upgrade the latest BACS thanks for that. I'm unsure about the config syntax...Is this the right lines to use for active mode? Do I need to activate LACP globally? Last question...As this will be used to setup 2 in one team accross a stack of switches, can this change conflict with existing port channels already defined/setup in "on" mode on the same stack of switches?

interface GigabitEthernet2/0/12
 description backupmedia
 switchport trunk encapsulation dot1q
 switchport mode trunk
 channel-protocol lacp
 channel-group 6 mode active

[Masoud Pourshabanian]

Hello,

You do not need to activate it globaly.

No, it does not conflict because you define mode per channel group.

Make sure you choose also LACP on your server.

Masoud