Understanding and illustration of VMware Workstation virtual network VMnet0, VMnet1, VMnet8

1. Description of the symbol in the text:
<a/b>: Can be understood as A, also can be understood as B.

2. Term
Modem: realizes the conversion between analog signal and digital signal, and can be neglected as a network cable.
Routers: Specialized devices that provide routing, DHCP, NAT, < capabilities/Services > connect to different networks (including connections between the LAN and WAN, providing Internet connectivity).
< switch/multi-interface Network bridge: switch and Network bridge function similar, basically can think is the same. If you really want to say where the difference is: two points, first, the number of interfaces is different, the number of switches than the Network Bridge interface, the second is the function of the implementation of different ways, the function refers to switches and bridges using bridging technology, the implementation of different means that the switch through a special < IC/chip > to achieve bridging function, But the network bridge does not have the specialized processing core, therefore the switch is quicker and more intelligent than the net bridge.
Interface (interface): Routers, the type of direct interpolation on a switch is called an interface.
--------------the evil split line-------------------------above bias hardware, the following biased software---------------------------
Port: As you all know, the WWW service is identified as 80, which identifies the FTP service as 21, and these numbers are called ports. For example, Www.baidu.com's IP is 119.75.216.30, then access www.baidu.com is essentially access to the 119.75.216.30 80 port 119.75.216.30:80.
Routing server: A server that provides routing < functionality/service >. If you join the routing server role on Windows 2003 server, you can provide routing < functionality/services, which is equivalent to a router-provided routing < function/service >.
DHCP server: A server that provides dhcp< functionality/services >. If you join the DHCP server role on Windows 2003 server, you can provide the dhcp< feature/service, which is equivalent to the dhcp< function/service provided by a router >.
NAT server: A server that provides nat< functionality/services >. If you join the NAT server role on Windows 2003 server, you can provide the nat< function/service, which is equivalent to the nat< function/service provided by a router >.

3. Understanding of hardware equipment and software (virtual) equipment
For example, see Figure 3.1, routers and servers with dual network adapters and installing Routing and Firewall < service/function > to build a multihomed network. Where is the routing < server role/service/feature > not just a "virtual router" installed on Windows 2003 server? Makes Windows 2003 server work in this network like a real router. In fact, if you install a software firewall on this Windows 2003 server, this software approach is not exactly the same as a hardware firewall that actually exists on the web.
So, from a functional perspective,< physical/practical/hardware > Equipment and < virtual/software > devices are the same, you can see < virtual/software > equipment as a real hardware device. However, from the design and performance, the two are qualitative differences, the former is designed by the electronic integrated circuits and micro-program to achieve the function, and the latter is programmed by the software to CPU processing to complete, the former performance far more than the latter.
When these concepts are clear, the virtual machines as well as the virtual devices can be seen at a glance. We can make the software virtual out of the hardware equipment openly in our network structure, as they are real.

4. VMware Workstation Virtual Network
4.1. Virtual network components
Virtual < NIC/network adapter: See Figure 4.1. Installing a Virtual PC automatically installs a virtual < NIC/network adapter, which adds multiple virtual network adapters.
Virtual switches: See Figure 4.1. 10 virtual switches are installed automatically when the VM is installed.
Virtual Bridge: Virtual Network Bridge is only applied when the virtual NIC is connected to the VMnet0 (default bridged) virtual switch.
Virtual DHCP server: see Figure 4.2. When a virtual NIC is connected to a VMNET1 or VMnet8 virtual switch, the virtual DHCP server is automatically installed and connected to this virtual switch.
Virtual NAT server: see Figure 4.3. The virtual NAT server is automatically installed and connected to this virtual switch only when the virtual NIC is connected to the VMNET8 (NAT) Virtual Switch.
Host virtual < NIC/network adapter: See Figure 4.4. The equivalent of a real network card, is connected to the host and Virtual Switch network card.

Figure 4.1 Virtual network card and Virtual Switch

Figure 4.2 Virtual DHCP server

Figure 4.3 Virtual NAT server

Figure 4.4 Host Virtual < NIC/network adapter >

4.2. VMnet0 (Default bridged)
4.2.1. Virtual network components to use
Virtual < NIC/network adapter >
Virtual switches
Virtual Network Bridge
4.2.2. Virtual network structure diagram

4.2.3. Virtual network structure of general family networking

4.3. VMnet1 (host-only)
4.3.1. Virtual network components to use
Virtual network < NIC/network adapter >
Virtual switches
Virtual DHCP server
Host virtual < NIC/network adapter >
4.3.2. Virtual network structure diagram

4.3.3. Virtual network structure of general family networking

4.4. VMnet8 (NAT)
4.4.1. Virtual network components to use
Virtual network < NIC/network adapter >

Virtual switches
Virtual DHCP server
Host virtual < NIC/network adapter >
Virtual NAT Device
4.4.2. Virtual network structure diagram

4.4.3. Virtual network structure of general family networking



About Vmnet1~vmnet8 (Linxu network Connections under virtual machines)

The

First vmnet0, in fact, is a virtual network bridge, which has a number of ports, a port used to connect your host, a port to connect your virtual machine, their location is Peer-to-peer, who is not who's gateway. So in bridged mode, you can make a virtual machine the same status as your host machine.


Again Vmnet1, this is a host-only network mode, which is used to build an isolated network environment, where Vmnet1 is also a virtual switch, one port of the switch is connected to your host, The other port is connected to the virtual DHCP server (which is actually a component of VMware), and the remaining port is the virtual machine. The virtual NIC "VMWare virtual Ethernet Adapter for VMnet1" serves the virtual machine as a gateway interface to the virtual machine. After the virtual machine is started, if you use the ipconfig command, you will clearly see that your default gateway is the address of the "VMWare Virtual Ethernet Adapter for VMnet1" network card. (It doesn't actually provide a route, it's a VMware design, it's doing something other than providing a route-actually I don't know what it does), and there's no routing here that doesn't provide NAT service, So that the virtual machine can not access the address of the network segment specified in the host-only mode, look at the picture can be very clear:  
 

Again Vmnet8, this is a NAT way, the simplest way of networking, from the host of "VMWare Virtual Ethernet Adapter for VMnet8 "VPN, connect to the VMNET8 virtual switch, the other port of the virtual switch connects to the virtual NAT server (this is also a VMware component), and one port is connected to the virtual DHCP server, Other virtual machines, virtual machine gateway is the "VMWare virtual Ethernet Adapter for VMnet8" card machine, nonsense, this must be your host machine. Also, as you can see with ipconfig, your virtual machine's default gateway also points to your "VMWare virtual Ethernet Adapter for VMnet8" virtual network card address. In contrast, it can be seen that NAT networking and host-only way, the difference lies in whether a more NAT service, see figure:  

Some beginners to the VMware Virtual Machine Bridge, VMnet1 (host-only), VMnet8 (Nat way), I have VMware the meaning of the network card three map, I hope to help.
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Vmnet1 is host-only, that is, choosing to use Vmnet1 is equivalent to VMware providing you with a virtual switch that only connects the virtual machine to the real system, and the virtual machine can share files with the real system, but the virtual machine cannot access the external Internet, And Vmnet8 is NAT, is the network address translation, equivalent to give you a virtual switch, the virtual machine and the real system to connect, while this virtual switch and the external Internet connection, so that virtual machines and real systems can be shared, but also access to the external Internet, And the virtual machine is borrowed from the real system IP Internet, will not be limited by IP-MAC binding.

From: http://hi.baidu.com/slip2008/blog/item/5667864bab91b8fd82025cd0.html