Differences in bridging, NAT, and host mode provided by VMware virtual machines

VMware offers three operating mode bridging (bridge), NAT (network address translation), and host-only (host mode).

2. Bridging mode

   In bridging mode, VMware's virtual operating system is like a standalone host in a local area network (hosts and virtual machines are in a peer position), and it can access any machine on the network. In bridge mode, we often need to configure the virtual host IP address, subnet mask, etc. (note that the IP address of the virtual host and host IP address in the same network segment).

   The relationship between a virtual system and a host using bridged mode is like two computers connected to a hub, and for them to communicate they need to configure the IP address and subnet mask for the virtual system. If we need to establish a virtual server within the LAN, and provide services for local area network users, then choose the bridging mode.

   But for friends who want to do a variety of network experiments, this mode is not very suitable, because you can not control the network of virtual machines, it went directly out.

4. Nat mode

   In NAT mode, the virtual system needs the NAT (Network address translation) feature. Access the public network through the network where the host machine resides. In other words, using a NAT mode virtual system can access the physical host as a router to the Internet. The TCP/IP configuration information for a virtual system in NAT mode is provided by the DHCP server of the VMNET8 (NAT) virtual network and cannot be modified manually, so the virtual system cannot communicate with other real hosts on the local area network. The biggest advantage of using NAT mode is that virtual system access to the Internet is very simple, you do not need to do any other configuration, only the host machine can access the Internet.

   This approach also enables two-way access to the host OS and the guest OS. However, other machines within the network cannot access the Guest os,guest OS can access other machines within the network through the host OS with the NAT protocol. The NAT mode IP address configuration method is assigned a ip  by VMware's virtual DHCP server, and the route is set in this IP address, which points to 192.168.138.1. If you want to use VMware to install a new virtual system, you can directly access the Internet without any manual configuration in the virtual system, it is recommended that you use NAT mode.

   In this way, there is a virtual NIC Vmnet8 (by default), if you have the experience of doing a NAT server, where the VMNET8 is the equivalent of connecting to the intranet network card, and the virtual machine itself is equivalent to running the machine on the Internet, The network card within the virtual machine (eth0) is independent of the vmnet8.

   You will find that in this way, VMware's own DHCP is loaded into the Vmnet8 interface by default, so that the virtual machine can use the DHCP service. More importantly, VMware comes with a NAT service that provides address translation from Vmnet8 to extranet, so this is a real NAT server running, but for virtual machines. Obviously, if you have only one extranet address, this approach is appropriate.

6. Host mode

   In the host mode, the real environment and the virtual environment are separated, in this mode, all the virtual systems can communicate with each other, but the virtual system and the real network are isolated. (Virtual systems and host machine systems can communicate with each other, which is equivalent to the two machines being interconnected by twisted-pair wires.) ）

   This should be the most flexible way to be interested in a variety of network experiments. Unlike NAT, the only difference is that, in this way, there is no address translation service, so by default, the virtual machine can only be accessed by the host.

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Differences in bridging, NAT, and host mode provided by VMware virtual machines