Can two ports in LACP group separately go to two different Nexus switches?

netappmagic · ‎2013-10-04

I have two 10G ports on NetApp filer, and they are formed as a LACP group. To keep redundancy, can these two ports go to two different CISCO Nexus switches model 5545?

Thanks for your information!

aborzenkov · ‎2013-10-05

Yes if Nexus ports are configured in vPC (virtual port channel).

netappmagic · ‎2013-10-06

Thanks for your message.

Is vPC usually enabled or disabled in normal circumstance? what impact on the switch if I wanted to enable it? The reason I am asking these is because our networking guys told me that two ports in LACP could not be connected to two different NX switches. So, I am wondering what difficulties are to stop them to do so.

Thanks for your further advices!

CHRIS_K_AU · ‎2013-10-06

Not by default, just create the vPC port group config on the switches. A 'normal' lacp ifgrp on the filer side is all you need. Remember to trunk the vPC if you are vlan tagging on the filer.

aborzenkov · ‎2013-10-06

It’s not that simple. Switches must be configured in vPC cluster, you need extra ISL connections as well as additional heartbit one.

aborzenkov · ‎2013-10-06

I’m not networking specialist so I guess you better discuss it with your network guys. If anything, using vPC mean spending 4 to 6 additional ports only to interconnect switches together.

netappmagic · ‎2013-10-07

aborzenkov,

You sounds pretty familiar with tht sese options. you are right, we should talk to networking guys, but we heard different things from them, so, that's why I wanted to get some ideas myself.

It sounds a lot of efforts or costly on networking side. Then what we can do on NetApp side? If we don't go with vPC approach on network side, what can we do to resolve the single point failure on the switch? when tthe switch went down, it will cause the entire LACP (2 ports) going down as well.

aborzenkov · ‎2013-10-07

For independent switches the only option is to use single mode VIF. It won’t work with LCAP. It is possible to use single mode as secondary VIF with LACP to individual switches as primary.

netappmagic · ‎2013-10-07

I am sorry, but I could not quite follow you.

currently, we are using 2-ports LACP group on each 2-node HA filer, A vlan is created on these two ports on each filer, so, two vlan's from two filers respectively are pointing to two different switches. If one switch went down, and then we will lost one filer, since as I understand it, in case like this, the failover would not happen.

Could you please elabrate your idea more, or recommend any document to prevent the single point failire on the switch?

Thanks a lot!

CHRIS_K_AU · ‎2013-10-07

A really good reference for this type of configuration is the Cisco document "VMware vSphere 5.1 on FlexPod Data ONTAP Operating in 7-Mode Deployment Guide", its a comprehensive guide on how to set everything up, including commands and config file listings.