Wireless Access

We are planning on downgrading ArubaOS from 6.3 to 5.0 due to DHCP limitation.  Is OS downgrade supported?  If so, can someone please provide information on how?

It is supported but make sure you verify following:

- Controller supports 5.x

- APs attached to the controller supports 5.x

- And also there's a lot of features that will not function after you downgrade

I would suggest going down to 6.1 rather than 5.0.

The instructions are in the release notes.

Please contact support before proceeding this step. I'm not sure what exact DHCP limitations you are referring to, but during time it has become clear that the DHCP server in the controller has been desiged and works fine for smaller deployments, but will not work at large-scale. For those deployments, typically external DHCP servers are used. Because people were deploying the built-in DHCP server for large scale production, a warning was added to the release notes to make this clear. As far as I know, the DHCP server was not changed to introduce capacity limits. 

 

So it might be that downgrading results in a situation where you are still in an unsupported configuration or risk to run into the same issues as with version 6.

 

Please open a TAC ticket to verify that your downgrade will indeed solve your issue.

 

Herman

The recommendation was always a max of 512 active leases.  That has now been rigidly enforced and instead is based on the pool size.

The problem with downgrading to avoid that restriction is that the internal dhcp will silently fail without warning when too many clients request addresses.