Wireless Access

Hi guys, I have a situations with two Mobility MC's in two locations which are recently connected with L2. Both controllers are active and have the same Master Controller which is located at HQ. Both MC's have AP's connected to them and due to the fact that I want to create redundancy I want to move both MC's into a cluster. I will use VRRP vip's to let the AP connect primary to there local controller, and have the other one as a backup (backup LMS).

I 'am planning to this configuration remote, because the controllers are in a different country. But I have the following questions:

- When I create the cluster on the MM and make both MC's part of it, will they or the AP's lose there config?

- Is this possible anyway, when the controllers already have AP groups etc.

- Both MC's are in a different Hierachie level, do I have to move them to the same level or can they stay in there own level?

So, I need to be sure that I can perform this remote and I don't have to make the MC factory default first.

Thanks for any help and suggestions.

- I 

Hi 

I understand that you are worried about Downtime from your concerns below:

- When I create the cluster on the MM and make both MC's part of it, will they or the AP's lose there config?

- Is this possible anyway, when the controllers already have AP groups etc.

- Both MC's are in a different Hierachie level, do I have to move them to the same level or can they stay in there own level?

-When you are moving one MC to another folder or role, the MCs will be rebooting to reflect the changes, In general, the APs will reboot when they lose contact with the MC unless there is VRRP Standby/HA Backup/LMS-BLMS

-If you have VRRP IP already you can make use of it by pointing the Master IP to the VRRP IP, like in Aruba OS 6.x or you can use the LMS and BLMS if you are sure that APs have reachability to the both MCs already

-Then if you go ahead and change the MCs to the new Cluster folder, there will be no down time required

In your case, I would suggest you can keep one controller in the same folder and move the other controller and make the necessary changes.

This will help you to reduce the duration of the Downtime or no need of it at all.

Jeeva Selvakumar

Hello Jeeve,

Thanks for your reply.

After you answer I did some thinking and maybe the best way is:

1) Connect both controllers also to the L2 connection vlan between the locations

2) Change all AP's to the controller IP-adres on the L2 vlan, with BLMS to the other one

3) First move one MC to the desired hierarchy level

4) Seondary, move the othe MC to the same level

5) Create the MC cluster

6) setup 2 VRRP's and let the AP's connect to their closest VIP 

regards,

Jan

Two controllers in a cluster are expected to be physically close to each other, in general.  They are also expected to have access to the same layer 2 VLANs.  If they do not have both of those things, you lose the advantage of a cluster, because users and access points do not always terminate onto the controllers that they are physically near to.  If an access point at one location terminates its tunnel on one controller, but its users on a controller at a separate site, the latency and performance would be unbearable.  If the controllers are not close to each other, they could also disconnect randomly from each other, creating disruptions and a "split brain" issue.  We have seen many create clusters with two controllers that have latency between them and it has caused issues.

Clustered controllers are expected to be physically close to each other, to leverage high speed connections to them so that they appear as a single controller to users and access points.  If that is not the case, you should have separate controllers, where access points are pointed to the controller at their site via LMS.  Backup LMS could be employed to fail those access points over to the opposite site, if redundancy is needed.