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LACP with Cisco Switches and NetApp VIFs

In my previous article about using NetApp multi-mode VIFs with Cisco switches, I mentioned that you could—at that time—only use 802.3ad static link aggregation:

Be aware that Data ONTAP’s multi-mode VIFs are only compatible with static 802.3ad link aggregation; you can’t use PAgP (Cisco proprietary protocol). I would assume dynamic LACP is also incompatible. For this reason we used the channel-group 1 mode on statement instead of something like channel-group 1 mode desirable.

I recently got some feedback from a NetApp SE in my area; this SE informed me that Link Aggregation Control Protocol (LACP, part of the IEEE 802.3ad specification) is indeed supported with Data ONTAP version 7.2. This KB article on the NetApp NOW site (login required) indicates that ONTAP 7.2.1 is required in order to use a LACP VIF.

There are a couple important requirements to note; these are laid out in the referenced KB article:

  1. Dynamic multimode VIFs should use IP address-based load balancing. This means that the Cisco switch or the channel group must also use IP address-based load balancing.

  2. Dynamic multimode VIFs must be first-level VIFs. This makes sense; LACP is a Layer 2 protocol, so layering a LACP VIF on top of other VIFs just doesn’t work.

To create the dynamic multimode VIF on the Data ONTAP side, the command is pretty simple:

vif create lacp <vif name> -b ip <interface list>

On the Cisco side, the commands are very similar:

s3(config)#int port-channel1  
s3(config-if)#description LACP multimode VIF for netapp1  
s3(config-if)#int gi0/23  
s3(config-if)#channel-protocol lacp  
s3(config-if)#channel-group 1 mode active

These commands would be repeated for all physical ports that should be included in the LACP bundle. Note the differences from the earlier commands in the previous article; here we use channel-group 1 mode active instead of channel-group 1 mode on. We also added the channel-protocol lacp command.

Together, these commands will establish a LACP-based link aggregate between a NetApp storage system running Data ONTAP version 7.2.1 or higher and a Cisco IOS-based switch.

Thanks to Jeff, our NetApp SE, for providing the updated information.

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