ArubaOS and Controllers

Occasional Contributor II

Named VLANs, backup-LMS and failovers

Hi all,

We're beginning a rearchitecture of our controllers here, and trying to move away from spanning any single VLAN to multiple controllers. (They're in separate buildings at separate core locations). We have three M3s, one per core, each with a unique client VLAN. I'm planning to run a single VAP configuration that references a named "user" VLAN, which is different on each LMS. I'll enable L3 Mobility (we're L2-mobile right now) to take care of roaming users.

Since the LMSes are each on their own network, we're using backup-lms for redundancy rather than VRRP. This has been used in the past and works *fairly* well, although we have problems with APs erroneously flipping from their backup from time to time...

The question I have is how this will behave in a failover state. Assume we lose a controller that maps the "user" VLAN to VLAN 10. There will be a break in AP availability as the APs rebootstrap on the backup-lms (assume it maps "user" to VLAN 20). The impression I get is that when this happens, stations will drop off the net, reassociate, terminate on the backup-lms, be placed in VLAN 20 instead of 10, and will request/receive a DHCP lease from VLAN 20's subnet.

Has anyone dealt with a similar architecture? Does it work? Suggestions as to how we could do this better?

Guru Elite


Yes, the APs will down their radios and rebootstrap to the backup controller. That gives the clients a chance to re-ip, just in case VLAN 10 is NOT the same subnet. If the radios did not go down, the clients would think they are on the same VLAN.

*Answers and views expressed by me on this forum are my own and not necessarily the position of Aruba Networks or Hewlett Packard Enterprise.*
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