Level 2 MiNT Links - Single AP importance

Userlevel 2

I have a question regarding Level 2 Links.

I noticed that when Level 2's adoption mode is activated, only one Access Point appears in each RF-Domain.

This single Access Point Access Point adopted, in the case by the VX9000, does something "different"? For example, if I have an adopted Access Point generating Crash Log, can it mess up the entire RF-domain, causing disconnects or something like that?

Thanks in advance.

5 replies

Userlevel 4
I'm not entirely sure by what you mean when you say "only one Access Point appears in each RF-Domain" but when you have a Distributed deployment (controller in NOC and APs in remote sites) you should be using Level-2 MiNT links between each site (RF-Domain) and the controller.

At each RF-Domain, one of the APs will be automatically elected as the RF-Domain manager and will retain its level-2 MiNT link with the controller. All of the other non-RF-Domain manager APs at the site (RF-Domain) will drop their initial existing level-2 links with the controller and then just establish level-1 MiNT links with all the other APs within the RF-Domain (including whichever AP is the acting RF-Domain manager. From that point forward, stats and other communications between the controller and the site's APs are effectively 'proxied' through the RF-Domain manager AP. All of this is automatic.

The elected RF-Domain manager still behaves as an AP...but it also takes on some additional responsibilities. Examples would be collection of RF-stats from the other APs within the same RF-Domain, which it then uses to make decisions about channel/power planning and will tell the other APs what power/channel to use (if using SmartRF).
Another extra responsibility would be the distribution of firmware. When the controller tells a site (RF-Domain) to upgrade its firmware, the controller pushes out only 1 copy of the image to the RF-Domain manager AP at each site (RF-Domain). The RF-Domain manager will then distribute the image to the other APs within the RF-Domain...and then finally will upgrade itself.

In the event that the currently elected RF-Domain manager AP goes down (for whatever reason) another election will automatically take place, and another AP takes over.

As far as an adopted AP generating a crash log messing up the entire RF-Domain? Nope.
Userlevel 2
Its possible you do not have a control vlan correctly configured on your rf-domain.
If that is properly configured please ensure that all your APs at the site see each other as mint-neighbors on the control vlan you selected.
Userlevel 4
Ahh..Thanks, Daren. I think I understand what Richard is seeing now.

...and in that case, based on experience, if you don't have a defined Control-VLAN (or if the APs cannot establish their MiNT level-1 links between each other for whatever reason), then what you'll see in each RF-Domain is just 1 AP. (Reason for this below)

If the APs that exist within an RF-Domain can't 'see' each other on the network, then every AP in that RF-Domain thinks that they are the ONLY 1 AP in the RF-Domain, right?...and as such, they elect themselves as the RF-Domain manager...because they think they're the only one there!
This ends up leading to the issue you're seeing in the UI. If memory serves, you will also likely see that the 1 AP that shows up in the RF-Domain will change periodically (to a different AP).

Bottom line, as Daren said, confirm you have the control-vlan setup properly. After that, confirm that all of the AP within the RF-Domain can see each other via MiNT level-1 links.
On the controller, issue command on the CLI:

#show mint links on

The output will list all of the level-1 MiNT links the AP has established (should be one for each AP at the site). If all you see just a single level-1 MiNT link and it's labeled as "self", then that AP is not able to see the other APs in the RF-Domain. If that happens, confirm that the VLAN is not blocking MiNT traffic between the APs at the site.
Userlevel 2
Chris Kelly and Daren Ellis,

Many many many thanks for this explanation! You gave us a real class!

Solved my problem!

Control VLAN on Remote Sites is required. In my case i use dedicated VLAN for L2 Comm between APs in remote sites. Just some clicks solved.


Userlevel 4
Nice work, Richard! Looking good now!