•A network, which is a virtual Ethernet switch on a XenServer host. Network objects have a name and description, a globally unique UUID, and the collection of VIFs and PIFs connected to them.
Both XenCenter and the xe CLI allow configuration of networking options, control over which NIC is used for management operations, and creation of advanced networking features such as virtual local area networks (VLANs) and NIC bonds.
Networks
Each XenServer host has one or more networks, which are virtual Ethernet switches. Networks that are not associated with a PIF are considered internal and can be used to provide connectivity only between VMs on a given XenServer host, with no connection to the outside world. Networks associated with a PIF are considered external and provide a bridge between VIFs and the PIF connected to the network, enabling connectivity to resources available through the PIF's NIC.
VLANs
Virtual Local Area Networks (VLANs), as defined by the IEEE 802.1Q standard, allow a single physical network to support multiple logical networks. XenServer hosts can work with VLANs in multiple ways.
Note:
All supported VLAN configurations are equally applicable to pools and standalone hosts, and bonded and
Using VLANs with Management Interfaces
Switch ports configured to perform 802.1Q VLAN tagging/untagging, commonly referred to as ports with a native VLAN or as access mode ports, can be used with primary management interfaces to place management traffic on a desired VLAN. In this case the XenServer host is unaware of any VLAN configuration.
Primary management interfaces cannot be assigned to a XenServer VLAN via a trunk port.
Using VLANs with Virtual Machines
Switch ports configured as 802.1Q VLAN trunk ports can be used in combination with the XenServer VLAN features to connect guest virtual network interfaces (VIFs) to specific VLANs. In this case, the XenServer host performs the VLAN tagging/untagging functions for the guest, which is unaware of any VLAN configuration.
XenServer VLANs are represented by additional PIF objects representing VLAN interfaces corresponding to a specified VLAN tag. XenServer networks can then be connected to the PIF representing the physical NIC to see all traffic on the NIC, or to a PIF representing a VLAN to see only the traffic with the specified VLAN tag.
For procedures on how to create VLANs for XenServer hosts, either standalone or part of a resource pool, see the section called “Creating VLANs”.
Using VLANs with Dedicated Storage NICs
Dedicated storage NICs (also known as
Combining Management Interfaces and Guest VLANs on a Single Host NIC
A single switch port can be configured with both trunk and native VLANs, allowing one host NIC to be used for a management interface (on the native VLAN) and for connecting guest VIFs to specific VLAN IDs.
NIC Bonds
NIC bonds can improve XenServer host resiliency by using two physical NICs as if they were one. Specifically, NIC bonding is a technique for increasing resiliency and/or bandwidth in which an administrator configures two NICs
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