AP Groups in the Cisco Realm

Access point groups (AP groups) help us as wireless network designers/administrators control our wireless networks and distribute WLANs with better precision. For each AP group created we are allowed up to 16 WLANs to support… In fact, the first 16 WLAN ID’s are automatically assigned to what is called the ‘default-group‘ on a Cisco WLC — This is something to be cognizant of when deploying AP groups and WLANs on your network, because all of the APs that join your WLC can join this default group… by default.

We also have control over the RF in these AP groups thanks to RF Profiles. Creating RF Profiles to attach to our AP groups gives us the ability to set DCA/TPC thresholds, data rates and several other options.

You have the power! You have a lot of power to tune and distribute your WLANs with AP groups. There are other related topics that will be covered in upcoming posts, but the following will discuss how to construct an AP group and add an AP to the new group.

I am using a Cisco WLC 2504 (8.0.132.0), which will support up to 50 AP groups — The number of AP groups that are supported increases exponentially with WLC model upgrades.

We are picking up after my LAB-AP-1 has joined the controller… As you can see below, the AP has joined the default-group by default and will advertise all of the globally enabled SSIDs that are part of the default-group.

asis

An AP that joins your controller for the first time and immediately starts broadcasting all of your enabled WLANs that are part of the default-group (WLAN ID’s 1-16) may not be part of your wish list — This is preventable with an out-of-box configuration or by creating all of your WLANs with a WLAN ID of 17 or higher (if supported). 

The out-of-box feature, when enabled, will move all APs that are in the default-group to the out-of-box group and admin down their radios. This feature must be enabled under WIRELESS > RF Profile >> Enable Out Of Box.outofbox

To view the current AP groups navigate WLANs > Advanced > AP groups or show wlan apgroups from the CLI. I currently have 2 AP groups configured and “in production”, but we are going to pay attention to the default group and a new LAB-GROUP that I will create shortly.

apdescript

By selecting the AP group name we are able to drill down to see details of the AP group (these details are also visible via the same CLI command mentioned above).

defaultgroup

As you can see in the image above I am in the APs tab of the default-group, but several tabs are available. I encourage you to review each tab, but we are looking at the APs tab to display which APs are currently in the default-group (LAB-AP-1).

To the right are APs that are in other AP groups and an option to add or move APs to the current group. Fair warning — The AP will reboot to move from one AP group to another. 

Now that we have an understanding of the initial join process and the default-group, I am going to show how to create a new AP group and move the AP to that new group.

I have already created a WLAN and because I am using a 2504, I am limited to 16 WLAN IDs. Also, I do prefer using the CLI for certain tasks and I do believe that using the CLI makes you a stronger talent :0).

CREATE AP GROUP:

Navigate to WLANs > Advanced > AP groups >> Add Group

Create the new group name and description and then select Add. Next, select the newly created AP group name to configure options.

creategroup

Navigate to the WLANs tab and add each of the WLANs that you want in the group and the correct interface mappings… This is done one WLAN at a time and is a bit easier to script for the CLI.

wlans

The WLANs will appear in the WLANs tab after they are added.

wlan-added

I will cover RF profiles in another post, but if you have RF profiles built you will want to navigate to the RF Profile tab and attach the desired RF profile to AP group.

Navigate to the APs tab and select which AP’s you want to migrate to the new AP group. In our example I have selected LAB-AP-1. After selecting the AP, choose the Add APs button and review the warning that pops up. If you are prepared to reboot the AP and confident that you understand the warning, you should choose to continue.

move-ap

One particular warning that pops up with 3600 APs warns about APs with the 802.11ac module only broadcasting the first 8 WLANs on the 5GHz radio — This has nothing to do with the WLAN ID — Instead, how many total it will broadcast.

The AP will reboot into the new group after a few minutes. You are able to validate this by navigating WLANs > Advanced > AP groups and selecting the AP group you want to review.

done

VIA CLI for the above example:

config wlan apgroup add LAB-GROUP (AP Group name) OCEAN OF RF (description)

config wlan apgroup interface-mapping (maps WLAN to AP Group) add LAB-GROUP (AP Group created) 8 (WLAN ID) management (Interface Name to map)

config ap group-name LAB-GROUP LAB-AP-1 (Sets selected AP to AP Group)

  • Changing the AP’s group name will cause the AP to reboot.
    Are you sure you want to continue? (y/n)

I hope that you found this review helpful. If you have any questions or concerns, please reach out to me.

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