In general, if the network port of the host is connected to the network cable and can access the Internet, the default installation of the VM is as follows, in VM-Settings-Hardware-Network Adapter-Network connection, select the Bridged connection mode and disable the firewall under the window. Therefore, windows and VM can be pinged easily, however, when the network port of the host is not connected to the network, it is not so easy to ping each other. I encountered this problem in a project: the host's network port cannot be connected to the windows system on the host and the Ubuntu system on the VM must be bound to an IPv6 address to analyze the problem. At the same time, a solution is proposed. The VM network connection methods include Bridged, NAT, Host-only, and Custom. Let's take a look at the first three connection methods (I haven't figured it out yet ). Bridged: bridges connect virtual machines to the LAN of your host. This is the easiest way to allow virtual machines to access the network of the host. In this case, the virtual machine needs its own identification. For example, the TCP/IP network needs its own IP address. This IP address is obtained from the network administrator, and other network details need to be set manually. In the bridge mode, a virtual machine is just like a host in a local network, just like a physical machine. If multiple virtual machines are running in vmware at the same time, each virtual machine should have an independent IP address. NAT (Network Address Translation NAT device): If the network of the host cannot provide an IP address to the virtual machine, NAT is the easiest way for the Virtual Machine to access the network of the host machine. Because the virtual machine does not have an external physical network IP address, vmware establishes an independent private network on the host machine and obtains the IP address through the Virtual DHCP server. NAT can differentiate the network data of multiple virtual machines and transmit the data between the virtual machine and the external physical network. In NAT mode, many standard TCP/IP protocols can be used on virtual machines, such as HTTP, FTP, and TELET. However, computers on external networks cannot be connected to virtual machines by default. Therefore, virtual machines cannot provide services such as WEB browsing. Host-only (Host machine virtual network adapter): This mode allows virtual machines to communicate with the Host machine, but this virtual adapter does not connect to any external network, only special software such as a proxy server can be set up on the host machine to connect the virtual adapter to the physical adapter. In fact, virtual machines only connect to the host machine over the network. In addition, it should be noted that the switch components will be automatically installed as needed during the installation of vmware software. Like a real switch, it allows connecting multiple network components and allows up to nine switches to be mounted, named VMnet0-8 respectively. Three of them are allocated to the Net Bridge (VMnet0), host machine virtual network adapter (VMnet1), and network address translation NAT device (VMnet8) by default ). VMnet0, VMnet1, and VMnet8 can be seen in windows, but when the host pulls out the network cable, VMnet0 will automatically disappear and become invalid. This is why when the host is not connected to a network cable, the connection between windows and VM cannot be pinged in the Bridged mode. The solution here is clear: select the NAT mode, and select the VMnet8 IP address when the VM selects the ping operation for windows. Select Host-only mode. When the VM selects ping for windows, select the IP address of vmnet1. Note: When binding an IP address to Ubuntu on the VM end, it is best to bind all IPv4 and IPv6 addresses, even if only IPv6 is required, because only IPv6 IP addresses are bound, and when the network is connected, the specified Nic may not be bound.