Apple terminal associated wifi problem in a site

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 Apple terminal associated wifi problem in a site

On-site feedback that the Apple terminal cannot be connected to WiFi. The phenomenon is that the WiFi icon keeps circling, and at the same time, the IP address cannot be obtained. Android terminals are fine.

1)      First confirm whether the Apple terminal cannot be associated with WiFi or cannot obtain an IP address after being associated with WiFi. When the fault occurs, there is a display of the terminal on the AC.

The wlan client appears, but the IP address column is empty. It is suspected that the terminal cannot obtain an IP address.

2)      The ACG is used as the DHCP server on site, the address allocated on the ACG still has a margin, and the feedback from the Android terminal has been associated with no problem. Check the terminal DHCP interaction process by capturing packets on the ACG, and find that the terminal rejects the IP address assigned by the server.

3)      Then why does the terminal reject the IP address? By expanding DHCP

The message before Decline found that the ARP request sent by the terminal after obtaining the address received a reply in the network.

4)      Therefore, the Apple terminal thinks that the IP address assigned by ACG is in conflict, so it sends a DHCP rejection.

Confirmed by ACG, the destination address of the destination NAT in the field device configuration is configured as any, and at this time, the conversion interface is in the monitoring state. After the address is allocated by DHCP, when the terminal performs conflict check, the conversion interface will reply with an arp message. After receiving the arp message, the terminal considers that the address conflicts and does not use the allocated IP address, resulting in the terminal being unable to obtain an IP address.

So why can the Android terminal get the address? The verification mechanism of the Android terminal is not as complete as that of Apple. Although the ARP conflict is restored in the network, the Android terminal will continue to be used. When the Apple terminal cannot obtain the IP address, the phenomenon on the terminal is that the WiFi icon keeps turning in circles and cannot be lit, which easily makes the user feel that the association has failed. Therefore, when dealing with terminal association issues, we must pay attention to whether the terminal simply cannot be associated or cannot obtain an IP address after association.