Product SiteDocumentation Site

4.3. Networking in Hosts and Virtual Machines

Host networking refers to the configuration options possible for networking connectivity at the host level. Virtual machine networking refers to virtual machine network interactions.

4.3.1. Host Networking Configurations

Common types of networking configurations for Red Hat Enterprise Virtualization hosts include:
  • Bridge and NIC configuration.
  • Bridge, VLAN, and NIC configuration.
  • Bridge, Bond, and VLAN configuration.
  • Multiple Bridge, Multiple VLAN, and NIC configuration.

4.3.1.1. Bridge Configuration

The simplest host configuration in Red Hat Enterprise Virtualization is the Bridge and NIC configuration. As Figure 4.3, “Bridge and NIC configuration” depicts, this configuration uses a bridge to connect one or more virtual machines (or guests) to the host's NIC.
Bridge and NIC configuration
Figure 4.3. Bridge and NIC configuration

An example of this configuration is the automatic creation of the bridge rhevm when the Red Hat Enterprise Virtualization Manager installs. On installation, the Red Hat Enterprise Virtualization Manager installs VDSM on the host. The VDSM installation process creates the bridge rhevm. The rhevm bridge then obtains the IP address of the host to enable management communication for the host.

4.3.1.2. VLAN Configuration

Figure 4.4, “Bridge, VLAN, and NIC configuration” depicts an alternative configuration that includes a virtual LAN (VLAN) to connect the host NIC and bridge.
Bridge, VLAN, and NIC configuration
Figure 4.4. Bridge, VLAN, and NIC configuration

A VLAN is included to provide a secure channel for data transfer over this network and also to support the option to connect multiple bridges to a single NIC using multiple VLANs. For more information on VLANs, refer to Section 4.1.2, “Bridge”

4.3.1.3. Bridge and Bond Configuration

Figure 4.5, “Bridge, Bond, and NIC configuration” displays a configuration that includes a bond to connect multiple host NICs to the same bridge and network.
Bridge, Bond, and NIC configuration
Figure 4.5. Bridge, Bond, and NIC configuration

The included bond creates a logical link that combines the two (or more) physical Ethernet links. The resultant benefits include NIC fault tolerance and potential bandwidth extension, depending on the bonding mode.

4.3.1.4. Multiple Bridge, Multiple VLAN, and NIC configuration

Figure 4.6, “Multiple Bridge, Multiple VLAN, and NIC configuration”. depicts a configuration that connects a single NIC to two VLANs. This presumes that the network switch has been configured to pass network traffic that has been tagged into one of the two VLANs to one NIC on the host. The host uses two VNICs to separate VLAN traffic, one for each VLAN. Traffic tagged into either VLAN then connects to a separate bridge by having the appropriate VNIC as a bridge member. Each bridge is in turn connected to by multiple virtual machines.
Multiple Bridge, Multiple VLAN, and NIC configuration
Figure 4.6. Multiple Bridge, Multiple VLAN, and NIC configuration

4.3.1.5. Multiple Bridge, Multiple VLAN, and Bond Configuration

Figure 4.7, “Multiple Bridge, Multiple VLAN, and Multiple NIC with Bond connection”. displays a configuration that bonds multiple NICs to facilitate a connection with multiple VLANs.
Multiple Bridge, Multiple VLAN, and Multiple NIC with Bond connection
Figure 4.7. Multiple Bridge, Multiple VLAN, and Multiple NIC with Bond connection

Each VLAN in this configuration is defined over the bond connecting the NICs. Each VLAN connects to an individual bridge and each bridge connects to one or more guests.