Wired Intelligent Edge

Hi,

I have two new 5406R zl2 Switches and one additional management module (so I got a total of three management modules). I came accross this thread:

http://community.arubanetworks.com/t5/Campus-Switching-and-Routing/5400R-VSF-Redundant-management-cards/td-p/271401

and it made things pretty clear for me that I can't enable nonstop-switching in VSF mode. When I insert the additional management module all lights (of the module) are lit but it can't take over if I pull the other. When I try to enable nonstop-switching with

redundancy management-module nonstop-switching

I only get "Invalid input". But since I now have the additional management module I have to ask again:

1) The previous thread is ~1.5 years old. Is it still not possible to use an additional module in VSF mode? (Firmware 16.05.0004)

2) If not, is there a chance it's gonna be in the future?

And finally I came to wonder if I should stick with VSF mode. None of my access switches is connected to both 5406R since they are not "important" to me. The only devices connected to both switches are 4 Servers (3x ESXi and 1x Windows 2012 R2 for backup purposes). Right now thats 1GbE for iSCSI and Network, I plan to migrate to 10GbE DAC and fibre. So the question is:

3) Would it be possible to configure ESXi and Windows 2012 R2 to work with two switches (still connected to each other) instead of one stack?

4) What would be your best practice in this case? VSF doesn't seem to be this much of a benefit for me.

thx

If i remember correctly, you can only use one management module in VSF mode. If it will disable the other i am not sure, but i remember reading this in the literature somewhere..

Yes, the seconed post in the above linked thread is very specific about that and most of the information I read or was told indicated the same. So question 1) was more rhetorical but I also was told different so it doesn't seem that obvious.

Question 2, 3 and 4 are still not answered to me.

It's correct the second MM will be shutdown but it's better to remove from chassis to make sure it can not become active.

1. Yes, it is still valid (sigh!).
2. Who knows? as a potential feature (having redundant MMs and VSF together concurrently) it would be great...but that's a question that only Product Development can eventually answer (if permitted to do so in a public thread!).
3. Yes (don't know exactly the vSphere part): try to see if Distributed Trunking with ISC between the two 5400R zl2 is enough for you to provide some sort of Server(s) to Switch(es) redundancy without implementing virtual switching (VSF).
4. See above.

I will pass the feedback for points 1 and 2 along to engineering, to reinforce that the demand is there for the feature.

With regards to 3 and 4: as parnassus suggested, Distributed Trunking provides a good balance of providing link redundancy while maintaining separate control planes, eliminating the single management module per chassis restriction.

Thank you that looks promissing.

So from what I get by a first look I do the following:

1) disable VSF

2) Form a regular trunk (either trunk or lacp) of both links between the two switches allowing each vlan to communicate over that trunk.

3) Enable nonstop switching (just to not forget this even if its not part of distributed switching).

4) Configure a new vlan for ISC on all trunk ports connecting the switches. I´m not completely sure here:

a) It is a vlan only for ISC purposes.

b) Both switches listen with their management port to this vlan.

c) The vlan can be tagged to the existing trunk connecting both switches, no seperate link needed.

5) Enable dt-ports instead of trunk-ports on both switches to behave like a regular trunk on just one switch. I think this is part is as clear as it can be.

6) On my server side I have no different configuration. The links appear to be one regular trunk.

And:

Server OS is not aware of dt-trunking. As long as it can deal with regular trunk it can handle dt-trunks. Both links are active, the speed is aggregated.