Troubleshooting Tip: iPhone hostname info is empty on DHCP client monitor page

[yangw]

Description	This article describes the scenario when iPhone hostname info is empty on the DHCP client monitor, but the Windows device can display the hostname expected.
Scope	FortiGate v7.0,
Solution	The FortiGate detects the devices based on the MAC address in the Ethernet header information. From the MAC address, it is possible to know which Vendor and device type. To get more information including 'hostname', FortiGate uses DHCP (option 60 class identifier, option 12 host_name) parameters to detect the device info in this case. In the DHCP monitor page, the hostname column is empty for the iPhone device: The device info can be found by the command:  diag user device list vd root/0 ca:ec:ec:87:c6:a9 gen 50034 req 0 created 1623388s gen 139 seen 0s TWTAC gen 12558 ip 110.110.110.4 src mac ip6 fd00::71:b09a:a0bf:2a4f src mac hardware vendor 'Apple' src dhcp id 4670 weight 130 type 'Mobile Generic' src dhcp id 4670 weight 130 os 'iOS' src dhcp id 4670 weight 130 FortiGate received the device info above from DHCP and MAC address, there is no 'hostname' info. From the packet details below, the iPhone did not provide/support DHCP option 12 hostname info. To see the iPhone/iPad hostnames on FortiGate, disable the Private Wi-Fi address on the iPhone/iPad Wi-Fi settings. After disabling it, FortiGate will see the hostname for the iPhone/iPad.