Wireless Access

Hi community,

 

I have a customer that has three sites separated geographically, and connected by a MPLS network. Site 1 has a MC 7210 running 8.3, and site 2 and 3 will have MC 7210 as well, they are in the sale stage currently. Is there a way to provide redundancy between the three sites/controllers in a way that in case of a controller failure its set of APs will fail over other site/controller, all this without a dedicated MM or MCM? For example, in case of controller 2 fails, its APs will fail over controller 1. Reading documentation I see a MM/MCM is needed, and because they cannot terminate APs in ArubaOS 8, the MM/MCM must be dedicated. Customer will purchase a MM in a future, not now because of financial contraints.

 

Regards,

Julián

Your only option is to stick to the legacy redundancy mode (aos6). But you don’t have hitless failover like you have in a cluster.

Yeah, it seems so. Though in my case with MM customer will not have hitless failover either, since the sites are connected through a MPLS network and the controllers' cluster will be L3, am i right?

 

Regards,

Julián

Yes, but then you need a MM. Also within a cluster you can’t specify a primary and secondary controller. In this case I will advise you to create a HA group like we did with AOS6

Right. Well, I wouldn't like to revert to ArubaOS 6, since I will have to downgrade the existing controller and when they purchase the MM, upgrade again... I will see what I do... In order to have redundancy like in my case, with ArubaOS 6 I would need three devices, because the master can terminate APs, but in ArubaOS 8 I will need one more device MM oir MCM... That's one shortcoming of ArubaOS 8...

 

Regards,

Julián

Honestly,

 

It is not favorable to do redundancy across a WAN link for an entire controller.  In most instances the performance is much worse over the WAN and would be painful to your users.  It is also not seamless, because all your users will have to obtain new ip addresses and their applications will disconnect.  If you consider controller redundancy important, the user should turn on cenralized licensing locally and add another controlller to the site. 

 

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@cjoseph wrote:

Honestly,

 

It is not favorable to do redundancy across a WAN link for an entire controller.  In most instances the performance is much worse over the WAN and would be painful to your users.  It is also not seamless, because all your users will have to obtain new ip addresses and their applications will disconnect.  If you consider controller redundancy important, the user should turn on cenralized licensing locally and add another controlller to the site. 

 

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Hi,

 

I completely agree with you. In my opinion, it would be ideal if my customer can afford two controllers in each site, but it can't. So in this scenario and if one of the controllers fails, it would be better if the APs and users can fail over to other controller over the MPLS with slow connectivity, than no connectivity at all. So until my customer can purchase one more controller for every site, I think this is the "less bad" solution. Anyway, for this, I would have to revert to ArubaOS 6, which would be painful...

 

Regards,

Julián

You don't need ArubaOS 6.x for access points to fail over to another controller.  ArubaOS 8.x can certainly do that.

 

Controllers honestly do not fail often, and many admins run into trouble planning redundancy they do not need and force outages as a result. Serious redundancy starts with the local site and then ends at a remote site as a last resort.  Remote site redundancy should honestly be a last resort, and not the first option.

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@cjoseph wrote:

You don't need ArubaOS 6.x for access points to fail over to another controller.  ArubaOS 8.x can certainly do that.

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Hi,

 

I know ArubaOS 8 can provide redundancy to another controller over a MPLS network, but can do that without MM or MCM? Because my customer can't afford a MM right now. It is the main question I asked at the beggining of the post:

 

Is there a way to provide redundancy between the three sites/controllers in a way that in case of a controller failure its set of APs will fail over other site/controller, all this without a dedicated MM or MCM? For example, in case of controller 2 fails, its APs will fail over controller 1. Reading documentation I see a MM/MCM is needed, and because they cannot terminate APs in ArubaOS 8, the MM/MCM must be dedicated.

 

Regards,

Julián

Backup LMS can be used without an MM.

 

 

Then, to be clear, I can configure LMS and backup LMS on ArubaOS 8 with three local MCs and without MM nor MCM?

Regards,
Julián

As long as you are going to individually manage the configs of 3 MCs, sure, but I think it would be problematic without an MM or MCM. you have to manually sinc the AP whitelists, manually sync configurations, etc. With 2 controllers you can run Active/Standby and they will sync up, but not 3 MCs.

 

Hi Jerrow,

 

So in my customer's case that can't afford a MM or MCM nor a second controller in every site right now, continue with ArubaOS 8 is not feasible. With ArubaOS 6 I can have a Master-Local topology, where the master controller terminates the APs of its site, and be the LMS backup of the other controllers. With ArubaOS 8 I can't do this without the problems you mentioned, am I right?

 

Regards,

Julián

That is correct.

OK, many thanks for the confirmation!

 

Regards,

Julián