VMware ESX/ESXi Networking Features Explained
Creating vNetwork Standard Switches
Define Virtual Network and Virtual Switch
A virtual network provides the networking for hosts and virtual machines that use virtual switches.
A virtual switch:
- Directs network traffic between virtual machines and links to external networks.
- Combines bandwidth of multiple network adapters and balances traffic among them. It can also handle physical network interface card (NIC) failover.
- Models a physical Ethernet switch:
- A virtual machine’s NIC can connect to a port.
- Each uplink adapter uses one port.
All network communication handles by a host passes through one or more virtual switches. A virtual switch provides connections for virtual machines to communicate with one another, whether they are on the same host or on a different host. A virtual switch allows connections for the management network on ESXi hosts and for the service console on ESX hosts. It also allows connections to access IP storage.
Virtual Switch Connections Types
A virtual switch allows the following connection types:
- VMkernel port:
- IP storage or vMotion migration
- For the ESXi management network
- One or more virtual machines port groups
- Service console port (ESX)
ESXi management network and ESX service console port are used to connect to network or remote services, including VMware vSphere Client. Separate IP stacks are configured for each VMkernel port and the ESXi management network port (or the ESX service console port). Each ESXi management network port and each VMkernel port must be configured with its own IP address, netmask, and gateway. The virtual machine port groups, VMkernel ports, and the service console port connect to the outside world through the physical Ethernet adapters that are connected to the virtual switch uplink ports.
Examples of Virtual Switch Connection
More than one network can coexist on the same virtual switch. Or networks can exist on separate virtual switches. When designing your networking environment, vSphere allows you to place all your networks on a single virtual switch. Or you can opt for multiple virtual switches, each with a separate network. Whatever the decision, depends on the layout of your physical networks. For example, you might not have enough network adapters to create a separate virtual switch for each network. You might instead team your network adapters to a single virtual switch and isolate the networks by using VLANS. A key point: Physical NICs are assigned at the virtual switch level, so all ports and port groups defined for a particular switch share the same hardware.
Types of Virtual Switches
A virtual network supports two types of virtual switches:
- vNetwork standard switches:
- Virtual switch configuration for a single host
- Discussed in this module
- vNetwork distributed switches
- Virtual switches that provide a consistent network configuration for virtual machines as they migrate across multiple hosts
Standard Virtual Switch Components Explained
A standard virtual switch provides connections for virtual machines to communicate with one another, whether on the same or different host. There are five standard virtual switches, each devoted to a different purpose.
- A standard virtual switch with a single outbound adapter being used only by VMI.
- An internal-only standard virtual switch, which allows virtual machines within a single ESX/ESXi host to communicate directly with other virtual machines connected to the same standard virtual switch. VM2 and VM3 can use this switch to communicate with each other.
- A standard virtual switch with teamed NICs. A NIC team provides automatic distribution of packets and failover.
- A standard virtual switch that is used by VMkernel for accessing iSCSI or NAS-based storage.
- A standard virtual switch that is used by VMkernel to allow remote management capabilities.
Default Standard Virtual Switch Configuration Explained
To view a host’s standard virtual switch configuration, click the Networking link of a host’s Configuration tab. ESXi installation creates a virtual machine port group and a VMkernel port. A good rule is to remove the VM Network virtual machine port group and keep virtual machine networks and management networks separated for performance and security reasons.
To remove a standard virtual switch, click Remove link next to the switch to be deleted. To display virtual switch properties, click Properties link next to the virtual switch.