Trunking on HP Procurve 2920

[Tom Lyczko]

I've been studying trunking etc. on HP switches, my head hurts :) :)

Anyway for the ports connected to vSphere hosts, it was easy to figure out that a static trunk is the best configuration since the host doesn't really do anything.

For connecting a Qnap TS-653 Pro to the 2920 with LACP, it seems the switch ports should be LACP passive and let the Qnap do the work of initiating the connection etc. when it needs to do so.

Does configuring either of these take the switch offline?? or require any downtime??

All this on the default VLAN.

Thank you, Tom

[EricAtHP]

Hi Tom,

First let's talk terminology. On ProVision devices, a trunk is a link aggregation. On others, including Comware based devices, a trunk is a link (could be a single link or a link aggregation) that carries more than one VLAN. In this case we are talking link aggregation, so we are good.

You want LACP Active, the default.

LACP Passive can only be assigned to ports that are not a member of a trunk. The idea here is that you can configure some ports on one side as active and then configure all ports on the other side as passive and the trunk will automaitically form. This is really only useful if you don't know which ports will get connected. I personally don't like auto configured options.

It is perfectly acceptible, and I recommend, to configure both sides of an LACP link aggregation (trunk) as active.

That said, what you propose should work too if the Qnap complies with the standard. You could configure all ports on the 2920 as passive or just the ports of interest:

interface all lacp passive
or
interface 1/1-1/4 lacp passive

None of these commands require a reboot of the switch. The ports will go down and come back up as LACP negotiates, probably not noticeable.

Hope this helps,
Eric

[Tom Lyczko]

OIC...as to the vSphere ports, these are the guest VM vSwitch ports, which have their NICs teamed within vSphere.

I don't have any specific LACP settings within vSphere, that's the other reason I thought of setting them as static trunk based on what I've read so far.

As to the Qnap ports, I don't know if the Qnap has any explicit settings for LACP active, though it appears it's LACP active by default: "Dynamic Link Aggregation uses a complex algorithm to aggregate adapters by speed and duplex settings. It utilizes all slaves in the active aggregator according to the 802.3ad specification. Dynamic Link Aggregation mode provides load balancing and fault tolerance but requires a switch that supports IEEE 802.3ad with LACP mode properly configured."

So I will set the 2920's two Qnap ports as LACP active as you suggest.

Thank you, Tom

[EricAtHP]

Yes, for your ESXi connection, LACP won't work unless you are using a VMware Distributed Switch on ESXi 5.1 or higher. So a static trunk (aka non-protocol trunk) is the right choice.

[Tom Lyczko]

OIC :) :) :) :) :)

Thanks a ton :) :) :) :)

I got the Qnap switch ports properly trunked and working okay with the Qnap -- I had to untag the trunk containing the Qnap ports on vlan 1, the default vlan.

I had to do more research to get the vSphere port trunking to work right -- the vSwitch had to be configured as well to route based on IP hash.

Everything is now properly trunked.

Thank you, Tom