Configuring the FortiAP units

Prior to providing a Remote WLAN FortiAP unit to an employee, you need to preconfigure the AP to connect to your FortiGate WiFi controller.

To pre-configure a FortiAP

1. Connect the FortiAP to the FortiGate unit.

2. Go to WiFi & Switch Controller > Managed FortiAPs and wait for the FortiAP to be listed. Click Refresh

periodically to see the latest information. Note the Connected Via IP address.

3. Go to Dashboard. In the CLI Console, log into the FortiAP CLI.

For example, if the IP address is 192.168.1.4, enter:

exec telnet 192.168.1.4

Enter admin at the login prompt. By default, no password is set.

4. Enter the following commands to set the FortiGate WiFi controller IP address. This should be the FortiGate

Internet-facing IP address, in this example 172.20.120.142.

cfg -a AC_IPADDR_1=172.20.120.142 cfg -c

5. Enter exit to log out of the FortiAP CLI.

 

Preauthorizing FortiAP units

By preauthorizing FortiAP units, you facilitate their automatic authorization on the network. Also, you can assign each unit a unique name, such as the employee’s name, for easier tracking.

1. Go to WiFi & Switch Controller > Managed FortiAPs and create a new entry.

2. Enter the Serial Number of the FortiAP unit and give it a Name. Select the appropriate FortiAP Profile.

3. Click OK.

Repeat this process for each FortiAP.

 

Features for high-density deployments

High-density environments such as auditoriums, classrooms, and meeting rooms present a challenge to WiFi providers. When a large number of mobile devices try to connect to a WiFi network, difficulties arise because of the limited number of radio channels and interference between devices.

FortiOS and FortiAP devices provide several tools to mitigate the difficulties of high-density environments.

 

Broadcast packet suppression

Broadcast packets are sent at a low data rate in WiFi networks, consuming valuable air time. Some broadcast packets are unnecessary or even potentially detrimental to the network and should be suppressed.

ARP requests and replies could allow clients to discover each other’s IP addresses. On most WiFi networks, intra- client communication is not allowed, so these ARP requests are of no use, but they occupy air time.

DHCP (upstream) should be allowed so that clients can request an IP address using DHCP.

DHCP (downstream) should be suppressed because it would allow a client to provide DHCP service to other clients. Only the AP should do this.

NetBIOS is a Microsoft Windows protocol for intra-application communication. Usually this is not required in high- density deployments.

IPv6 broadcast packets can be suppressed if your network uses IPv4 addressing.

You can configure broadcast packet suppression in the CLI. For example, to suppress ARP, downstream DHCP, NetBIOS, and IPv6 packets on the conf-net network, enter:

config wireless-controller vap edit conf_net

set broadcast-suppress arp-known arp-unknown arp-reply dhcp-down netbios-ns netbios- ds ipv6

end

 

Multicast to unicast conversion

Multicast data such as streaming audio or video are sent at a low data rate in WiFi networks. This causes them to occupy considerable air time. FortiOS provides a multicast enhancement option that converts multicast streams to unicast. A unicast stream is sent to each client at high data rate that makes more efficient use of air time. You can configure multicast-to-unicast conversion in the CLI:

 

config wireless-controller vap edit <vap_name>

set multicast-enhance enable end

 

Ignore weak or distant clients

Clients beyond the intended coverage area can have some impact on your high-density network. Your APs will respond to these clients’ probe signals, consuming valuable air time. You can configure your WiFi network to ignore weak signals that most likely come from beyond the intended coverage area. The settings are available in the CLI:

 

config wireless-controller vap edit <vap_name>

set probe-resp-suppression enable

set probe-resp-threshold <level_int>

end

 

vap_name is the SSID name.

 

probe-resp–threshold is the signal strength in dBm below which the client is ignored. The range is -95 to –

20dBm. The default level is -80dBm.