Appendix A: Using Aruba Instant in a Physical Site Survey
In the past, the centralized, thin nature of Aruba APs has led to some challenging experiences for users attempting a physical site survey. Surveys are especially difficult in buildings where no wiring is present. Users tried many solutions, including rolling mobility controllers around on a cart and using RAPs with preselected channels and power in an always-on mode. Aruba Instant simplifies physical site surveys by allowing users to set up a stand-alone AP quickly that can broadcast an SSID and uses the same hardware that will later be deployed in the environment.
When you use an Instant AP, the first thing that must be solved for is power. Though an external adapter is possible to use, we found it more convenient to use a PoE switch when existing wiring was in place, or a PoE injector when it was not. In Figure 46 we show the setup using an IAP-105 and a PowerDsine PD-9001G-AC power injector. A laptop running DHCP server software was also used.
Figure 46 IAP with a PoE injector
When using a power injector, note that the IAP needs an Ethernet link to come up until version 3.0. Without the link, the IAP assumes it is a mesh point. A mid-span power injector does not provide the link, it simply adds power as a transparent pass through. To provide the link, attach a second laptop or a switch to the LAN side of the injector.
The IAP assigns an IP address to itself if no DHCP source is discovered. We found it to be faster simply to enable a DHCP server on a laptop and connect that to the IAP through the power injector or switch. It takes about 2 minutes more to boot the AP without the DHCP server, and though that is not a long time, it does add up over the course of the day while moving the AP around a facility and waiting for it to boot. In our small test facility, that boot time would have added 20 minutes to the day. Having a laptop connected also allows for the use of tools for testing throughput.
Be sure that your DHCP server vends a DNS address even if it is not reachable. By default, the IAP intercepts the DNS request, which is important when you are trying to reach the virtual controller address.
In our testing, we found that either an open or PSK network are the easiest to deal with when configuring the system. We allowed ARM to adjust channels just as it would in the eventual production environment, but we restricted the power setting. We set the minimum and maximum to 15 dBm, which matches ARMs default minimum power. By using this power setting, we were able to simulate the network as if all the APs had powered down to minimum.
Table 5 Summary of IAP Settings
| Parameter | Recommendation |
|---|---|
| AP Power | PoE switch or power injector |
| Link | If a PoE switch is not used, attach a laptop or switch to the LAN side of the injector. |
| Encryption / Authentication | Open or PSK |
| Channel setting | Allow ARM to set channel, or pick a channel in the 5 GHz band. |
| Power setting | Set to the ARM minimum power (15 dBm by default) for both min power and max power. You can adjust this power if your clients will be using a different power level and you will be adjusting the ARM minimum on the controller or IAP. |
Configuring the IAP for Survey Use
The following steps will guide you through setting up an IAP for site surveys using the previously discussed settings. Test this setup ahead of time to ensure that all of your tools work and you understand how the system operates before you go on site.
Connect the IAP to an Ethernet connection with a link and provide power. The AP boots up, which you can monitor from the console port. After the AP has booted, it begins broadcasting an open SSID called “instant.” (See Figure 47.) Connect your wireless device to this SSID to begin the provisioning process.
Figure 47 Aruba Instant default SSID
After you are connected, browse to http://instant.arubanetworks.com. The IAP intercepts this address and you are taken to the web interface for the virtual controller as show in Figure 48. The default username “admin” and default password “admin” are used.
Figure 48 Virtual controller login
After you log in, you need to add an SSID and encryption. It is helpful to use an SSID that is obvious to you, because you can identify quickly that the IAP is up and running. You may also want to enable encryption using a PSK. This encryption is helpful or required for some networks, and it gives you peace of mind that no one can access the local network without your permission.
In the network box, the default Instant SSID and a link to create a new SSID are listed as seen in Figure 49. Click the new link to begin configuring your SSID.
Figure 49 Default SSID and new SSID link
The virtual controller opens a new setup wizard that has three steps. Step 1 is shown in Figure 50. Enter the SSID name that you have chosen and then click More.
Figure 50 New SSID name
The link opens additional settings that you can use. You may want to limit your SSID to the 5 GHz band, or if you are doing multiband scanning, you can skip this step. Figure 51 shows the additional settings and the band selection.
Figure 51 Setting the SSID to broadcast only on 5 GHz
Click Next to continue to the security settings. Here you configure the security level of the SSID, which is typically WPA2-PSK or open. If you select WPA2-PSK, enter your PSK as shown in Figure 52.
Figure 52 SSID security settings
Click Next to continue to the security settings. The final screen allows you to configure role-based access. You do not need to make any changes on this screen. Click Finish to complete the SSID setup. (See Figure 53.)
Figure 53 Access control settings
You should now see your new SSID in the network box on the dashboard. (See Figure 54.) You will use this SSID going forward.
Figure 54 New SSID is available
Connect your laptop to the new SSID you created and supply the PSK you configured when prompted to do so. When you log back into the management interface of the IAP, you will see that the Instant SSID has disappeared and the newly configured SSID is the only one present. (See Figure 55.)
Figure 55 Connected to new SSID
The next step is to configure the ARM settings to disable power level changes. By default, ArubaOS sets the ARM minimum power to 15 dB. In this case, we want our IAP to match that minimum power. If you are not using the default minimum, adjust the power setting to match your planned configuration.
Click the settings link in the upper right hand corner and then click the ARM tab as shown in Figure 56. You must adjust the min and max transmit power to be 15 dB.
Figure 56 IAP ARM settings
At this point your IAP is ready to use for active and passive survey testing.