Hello, if your DingTalk shows fails to link to the internet, please check it out as follows:
First, please check if your device is enabled for mobile network or wireless LAN,
if you need to connect to the Internet, please refer to the following methods:
1. Check if "Settings - Wireless LAN" is enabled in the phone and select an available network access;
2. Check if the "Setup - Cellular Mobile Network" in the mobile phone is turned on and the mobile phone is not down (the operator may charge the data communication fee after enabling the cellular mobile network).
Second, if you have access to the wireless LAN: 
1. Please check if the wireless LAN hotspot you are connecting to is connected to the Internet, or whether the hotspot has allowed your device to access the Internet.
Third, if your phone is an ios 10.x version of the system:  
You can try to switch to the wireless LAN assistant switch in the "Settings - Cell Phone Network - Wireless LAN Assistant", and then check if the nail can access the network.

Guess you want to learn more about：

Device shows offline.

M1 cannot connect to the network.

M2 cannot connect to the network

The terminal cannot connect to the Internet after connecting to C1.

M1/M1S network disconnected and reconnected.