When you can't go online,
Ping gateway
Restart the ICS service or RRAS service,
If not, check the NAT interface, IP allocation settings, and DNS settings.
If it is no longer, it is reconfigured.
If you are reconfigured,
Situation 1: More than one DHCP distributor in the network, conflict
Case 2: There are multiple gateways in the network, causing NAT or ICS auto-off. For example, a NAT connection two subnets, but only DHCP allocation with weaker NAT, should configure DHCP server
If
First, check the firewall, have opened the designated network address
Second, check IP settings
Third, ipconfig command
