Explanation
The wrong gateway is the most likely cause of the connectivity issue for the new VM that cannot access the Internet or the VMs on any other subnet. A gateway is a device or software that connects two or more networks and routes traffic between them. A gateway is usually configured as the default route for a network device, which means that any traffic that is not destined for the local network will be sent to the gateway. If the gateway is configured incorrectly, the network device will not be able to communicate with other networks or the Internet. In this case, the new VM has an IP address of 172.16.31.40/24, which means that its subnet mask is 255.255.255.0 and its network ID is 172.16.31.0. However, its gateway is configured as 172.16.30.1, which belongs to a different network (172.16.30.0/24). This means that the new VM will not be able to reach its gateway or any other network through it. The administrator should change the gateway to an IP address that belongs to the same network as the new VM, such as 172.16.31.1 or 172.16.31.254.