Configure a Cisco Mobility Express AP for an APoS Site Survey

November 23, 2017

APoS, cisco, mobility express, site survey

This article explains how to configure a Cisco Mobility Express AP for an AP-on-a-Stick site survey using the CLI (Command Line Interface). It is also possible to do it using the provisioning SSID.

Right before configuring the AP for the survey, I had to convert it from the CAPWAP mode to the Mobility Express mode.

STEP 1 - CONNECT TO THE AP

Connect to the AP via the console port. (I use AirConsole on macOS)

STEP 2 - SETUP WIZARD

When the AP boots for the first time in the Mobility Express mode, you are presented with a setup wizard. We will use the wizard to configure the following parameters:

IP address of the Mobility Express management interface: 192.168.88.11/24 (Note: The IP address of the Mobility Express controller has to be different from the AP IP address!!)
IP address of the gateway: 192.168.88.1
DHCP server for the Wi-Fi clients: 192.168.88.100-200
Time
Host name of the controller: surveyWLC
Admin credentials: Admin / Cisco123

You will notice that I am not configuring any WLAN profile yet. This will come later.

Here is how I configured mine (these parameters can be changed to match your environment):

Would you like to terminate autoinstall? [yes]:yes
Enter Administrative User Name (24 characters max):admin
Enter Administrative Password (3 to 24 characters max):Cisco123
Re-enter Administrative Password: Cisco123
System Name:[Cisco_3a:d2:b4] (31 characters max):surveyWLC
Enter Country Code list(enter ‘help’ for a list of countries)[US]:CA 
Configure a NTP server now?[YES][no]:no
Configure the system time now?[YES][no]:yes
Enter the date in MM/DD/YY format:11/22/17
Enter the time in HH:MM:SS format:11:30:00
Enter timezone location index(enter ‘help’ for a list of timezones):5 
Management Interface IP Address: 192.168.88.11
Management Interface Netmask: 255.255.255.0
Management Interface Default Router: 192.168.88.1
Create Management DHCP Scope?[yes][NO]:yes
DHCP Network: 192.168.88.0
DHCP Netmask: 255.255.255.0
Router IP: 192.168.88.1
Start DHCP IP address: 192.168.88.100
Stop DHCP IP address: 192.168.88.200
DoaminName: mewlc.local
DNS Server:[OPENDNS][user DNS]OPENDNS
Create Employee Network?[YES][no]:NO
Create Guest Network? [yes][NO]:NO
Enable RF Parameter Optimization?[YES][no]:no
Configuration correct? If yes, system will save it and reset.[yes][NO]:yes

Wait for the AP to reboot. You will be able to login into the controller using the admin username and the Cisco123 password.

user: admin
password: ********
Welcome to the Cisco Mobility Express command line interface.
Only commands which are listed in the command line reference guide for this release are supported
(Cisco Controller) &gt;

Once everything is configured, here are a couple of useful show commands that you could use to validate your configurations:

show interface summary
show time
show dhcp summary

STEP 3 - CONFIGURE THE SURVEY SSIDS

When I do AP-on-a-stick site surveys I like to configure the following SSIDs:

Open SSID called survey24 on the 2.4GHz band only
Open SSID called survey5 on the 5GHz band only

Here is how you can configure them on the Mobility Express controller via CLI:

(Cisco Controller) &gt; config wlan create 1 survey24 survey24
(Cisco Controller) &gt; config wlan radio 1 802.11bg
(Cisco Controller) &gt; config wlan security wpa disable 1
(Cisco Controller) &gt; config wlan enable 1
 
(Cisco Controller) &gt; config wlan create 2 survey5 survey5
(Cisco Controller) &gt; config wlan radio 2 802.11a-only
(Cisco Controller) &gt; config wlan security wpa disable 2
(Cisco Controller) &gt; config wlan enable 2

Once everything is configured, here are a couple of useful show commands that you could use to validate your configurations:

show wlan summary
show wlan wlan_id

STEP 4 - RADIO SETTINGS

I also like to keep control on the channel and transmit power used for the survey on both frequency bands. In this example, we are configuring the 2.4GHz radio on channel 1 with a transmit power level of 4 and the 5GHz radio on channel 36 with a transmit power level of 2.
Use the show config ap 802.11b ap_name and show config ap 802.11a ap_name commands to find out which power level corresponds to which dBm value for your AP.

First, you need to make sure that the AP joined the controller using the show ap summary command. In our case the name of the AP was surveyAP. If the AP didn’t join, make sure that you are using different IP addresses for the AP and the Mobility Express controller. Also, check out this article from Packet 6: Troubleshoot AP Joining Issues – Cisco Mobility Express.

Here is how you can configure these radio settings on the Mobility Express controller via CLI:

(Cisco Controller) &gt; config 802.11b disable surveyAP
(Cisco Controller) &gt; config 802.11b channel ap surveyAP 1
(Cisco Controller) &gt; config 802.11b txPower ap surveyAP 4
(Cisco Controller) &gt; config 802.11b enable surveyAP
 
(Cisco Controller) &gt; config 802.11a disable surveyAP
(Cisco Controller) &gt; config 802.11a channel ap surveyAP 36
(Cisco Controller) &gt; config 802.11a chan_width surveyAP 20
(Cisco Controller) &gt; config 802.11a txPower ap surveyAP 2
(Cisco Controller) &gt; config 802.11a enable surveyAP

Now, if you are using a Cisco Aironet 2800 or 3800 series AP, you will not have the 802.11b radio available. Instead, you will configure the 802.11-abgn radio.
If you try to configure the 802.11-abgn radio the same way we configured the 802.11b radio above, you will get the following error:

(Cisco Controller) &gt; config 802.11-abgn disabe surveyAP
(Cisco Controller) &gt; config 802.11-abgn channel ap surveyAP 1
(Cisco Controller) &gt; config 802.11-abgn txPower ap surveyAP 4
XOR radio is not manual mode
(Cisco Controller) &gt;

This is because, by default, the 802.11-abgn radio is set to the auto role.
We need to change the role to manual client-serving in order to be able to configure the custom transmit power.

Here is how to configure the 802.11-abgn radio:

(Cisco Controller) &gt; config 802.11-abgn disable surveyAP
(Cisco Controller) &gt; config 802.11-abgn role surveyAP manual client-serving
(Cisco Controller) &gt; config 802.11-abgn channel ap surveyAP 1
(Cisco Controller) &gt; config 802.11-abgn txPower ap surveyAP 4
(Cisco Controller) &gt; config 802.11-abgn enable surveyAP