Wireless Access

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Access network design for branch, remote, outdoor, and campus locations with HPE Aruba Networking access points and mobility controllers.
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best practice for two controller redundancy

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  • 1.  best practice for two controller redundancy

    Posted Mar 10, 2014 10:45 AM

    i have read through the VRDs (campus and controller) and the AruboOS 6.3 user guide, but im still a little unsure about what is the way to go.

     

    planning a two controller (same hardware, subnet) setup and would like to have the "best" redundancy, so the system should run fine without either of the two controllers. centralized licensing is a must and fast failover a nice to have, dont want to configure wlan settings on two devices.

     

    so what is the way to go: master / master-backup or master / local?

     

    anything else to consider? i understand that the future is something to think about, but i dont expect an extention controller wise any time soon.



  • 2.  RE: best practice for two controller redundancy

    Posted Mar 10, 2014 11:08 AM

     

    Hi boneyard,

     

    VRD's describes the bigger scenarios, but looking at the VRD "Aruba Mobility Controllers" still gives you the answer. Your scenario is a small network where your controllers will be handling both the Master and Local "roles" - in respect to the VRD view of things.

     

    Add that together and you get:

    • Page 46 "To achieve high availability of the master mobility controller, use the masterredundancy method .."
    • Page 48 "Active-active is Aruba’s recommended method of deploying redundant locals."

     

    Doing Active-Active Master isn't viable so common deployment combines that to be Master Active/Standby.

     

     

    Fail-over in this scenario is very fast. We've seen so low as just 4 pings (!) dropped from the client towards it's gateway when un-plugging the Active Controller. 



  • 3.  RE: best practice for two controller redundancy

    Posted Mar 10, 2014 11:47 AM

    thanks john, so master / master backup, indeed the way it setup this up before. but is that supported for centralized licensing and fast failover?

     

    from what i read fast failover takes away the VRRP (which master redundancy uses) or can it be used together with master redundancy?

     

    for centralized licensing i noticed this "If standby license server rebooted and come back while the license server is down, all license contributed by the license server will be removed on standby license server and license clients" which scares me. specially during an upgrade where the advise is to do all controllers at the same time i would expect the above situation to be quite possible.

     

    does centralized licensing even allow for terminating APs on the (backup) license server?



  • 4.  RE: best practice for two controller redundancy

    Posted Mar 10, 2014 05:46 PM

    Fast-failover is for failover using LMS Primary-Backup IP - ie. fail-over between Locals.

     

    A nifty thread in that regards:

    http://community.arubanetworks.com/t5/Unified-Wired-Wireless-Access/High-Availibility-Fast-Failover-Best-Practice/td-p/91438

     

    Centralized licensing in Master Active/Standby scenario is pretty straight-forward.

    Install all the licences on the Master-Master and activate Centralized licensing. License Redundancy is default when you have Master-Redundancy configured. 

    That is not to be mistaken with "secondary license server" tho, so don't let that line scare you :) 

     

    We're running a setup at our company exactly like the one you are describing, and it works like a charm. 2x 3600 on 6.3.1.3



  • 5.  RE: best practice for two controller redundancy

    Posted Nov 09, 2016 12:24 PM

    I want to migrate a Master and Standby Centralized License Servers (CLS) between two DataCenters.  They will be on different subnets.  Will failover work?  What are the Best Practices for this design and how should the controllers should be configured to support high availability.  Is this doable......will work.  Thank you in advance for you support.

     

     

     

    Sobers.



  • 6.  RE: best practice for two controller redundancy

    EMPLOYEE
    Posted Nov 09, 2016 12:29 PM

    Master redundancy requires L2. If the controllers are the exact same hardware, your fastest operation might be to take a backup of the old site, take it to the new site and restore the backup and relicense on the new master, then cut off the old and move the new. If IP addresses are changing, then you will also need to upgrade all locals, any DHCP scope options or DNS options for AP discovery, etc.
     



  • 7.  RE: best practice for two controller redundancy

    Posted Mar 11, 2014 12:55 AM

    Master redundnancy and centralized licensing are compatible.  The active master automatically becomes the primary licensing server and the standby master is the backup licensing server.

     

    Fast Failover is the suggested form of AP high availability.  Your APs will not be configured to point to a VRRP address.  However, VRRP is still necessary for the master redundancy.



  • 8.  RE: best practice for two controller redundancy

    Posted Mar 11, 2014 04:45 PM

    thanks for the replies jsolb and thecompnerd.

     

    from what i read on the thread below i would think that AP fast failover (which is a little more then only local failover) seems the better choice then just the VRRP address for the APs right?

     

    http://community.arubanetworks.com/t5/Unified-Wired-Wireless-Access/Centralized-Licensing-and-HA/td-p/137895/page/2

     


    @michaelw wrote:

    When Centralized Licensing is used in conjunction with HA, when a failure occurs and the standby tunnel becomes active, the controller will allow the AP to become active immediately even though the controller may report 0 license available momentarily on the standby controller.