Three major issues for deploying lightweight AP in enterprises (1)

In Cisco's unified wireless management policy, the wireless launch points are divided into two parts: lightweight AP and wireless LAN controller. The lightweight AP is only responsible for receiving and sending signals, while the wireless LAN Controller is responsible for client identity authentication and security policy management. Therefore, when deploying Cisco Wireless LAN, You need to properly deploy a lightweight AP so that it can be organically connected with the wireless LAN.

To help you better understand the deployment of lightweight AP, I will first talk about the working principle of lightweight AP. Then let's talk about the key points and precautions of the deployment based on the working principle. To put it simply, a lightweight AP can be divided into four steps from startup to normal operation.

Step 1: The lightweight AP obtains an IP address from the DHCP server. Although a lightweight AP is only a wireless access point, it is still a network device. To transfer data normally in the local area network, it still needs a valid IP address. Therefore, when starting the instance, the lightweight AP needs to obtain a valid IP address from the DHCP server.

Step 2: contact the wireless LAN controller. When a lightweight AP is started, the IP addresses of all wireless LAN Controllers are obtained through broadcast. If you do not consider other factors, it will first send a connection request to the first wireless LAN controller. If the wireless LAN controller does not respond, it will try the next IP address. When the wireless LAN Controller receives the request information, it sends the information to the lightweight AP. In this way, you can bind a lightweight AP with a wireless LAN controller.

Step 3: Compare and update the policy code. After the wireless LAN controller is bound with a lightweight AP, it compares its code impression version with the locally stored code image version. If some policies in the wireless LAN controller have changed before the connection, the lightweight AP will download and enable the latest impression code from the wireless LAN controller. But to take effect, the lightweight AP must be restarted.

Step 4: Create a tunnel. After the preceding three steps are completed, two tunnels are established between the lightweight AP and the Wireless LAN controller, namely the LWAPP control information tunnel for transmitting management information and the data tunnel for user data. These two tunnels cannot be used to achieve data load balancing, but have their own purposes. Even when client data is frequently exchanged, tunnels used to transmit control information do not need to be purchased to transmit data information.

It can be seen that the working principle of a lightweight AP is very simple. Most of its complex work, such as client identity authentication, is completed by an independent Wireless LAN controller. Therefore, when deploying a lightweight AP, the key is how to ensure the connection between the lightweight AP and the Wireless LAN controller. If the connection is interrupted, even if the lightweight AP works normally, the user still cannot send and receive information through this lightweight AP. To ensure effective connections between them, the network administrator should pay attention to the following issues.