Hi John, We just went through the same scenario. We now have an Aruba/Alcatel 6000 with dual controllers...200 AP's as well.
I concluded the following. 1.) Two controllers (same box) side A & B, A-side is active, B-side is redundant. A-side fails, B-side takes over 2.) Major/minor upgrade - Upgrade B-side, swap, everything looks good, do a copy/synch to the A-Side 3.) Major/minor upgrade - Upgrade B-side, swap, upgrade fails, revert back to A-side 4.) Minor hardware failure - 1 controller fails, still operational 5.) Major hardware failure - backplane failure = tons of phone calls Item #5 is my weakest link. However, because the 6000 has dual-everything (except the chassis), I felt my exposure was minimal. I could not justify the cost of an additional 6000 for 100% redundancy. I looked at the smaller boxes with decentralized distribution...but the smaller boxes couldn't handle all 200 AP's simultaneously....Plus it just adds complexity to our already overworked staff (troubleshooting would be more complicated). I hope this is helpful. Russ -----Original Message----- From: John Rodkey [mailto:[EMAIL PROTECTED] Sent: Tuesday, May 22, 2007 7:24 PM To: [email protected] Subject: [WIRELESS-LAN] 'Clustering' and 'failover' in the context of Aruba We are currently considering expanding our existing wireless environment to cover additional dorms. By doing so, we will exceed the capacity of our current controller, and can either add an additional controller card or for a slight incremental cost, add another controller. We planned to add the additional controller, with the idea that the controller would allow redundancy/failover/clustering to happen, so that if one controller were to go down, for instance, the other would take over. We were subsequently told that this was a faulty understanding of the failover function. So we thought we might be able to try another approach: every other WAP would be controlled by alternating controllers. That way, if controller A, with waps 1,3,5,7,9... on it were to go down, the coverage in any given building would be halved, because controller B, with waps 2,4,6,8 ... would continue to run. Nope, that is a bad idea, says the contact: each controller will maintain its own heat map and routing info, etc. and as a result, there would be nowhere to look for a unified picture of the wireless network. So I'm confused: what is the exact nature of controller clustering or failover under Aruba? Given somewhere in the neighborhood of 200 APs, how should one configure the controllers John ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
