About VXLANs
A virtual extensible LAN (VXLAN) defines a 24-bit LAN segment identifier to provide segmentation at cloud scale and an architecture that expands cloud deployments with repeatable pods in different Layer 2 (L2) domains. A VXLAN can also enable the migration of virtual machines (VMs) between servers across Layer 3 networks.
A VXLAN creates LAN segments by overlaying the original MAC (L2) frame in IP encapsulation from the VM within the Virtual Ethernet Module (VEM).
Each VEM is assigned an IP address, which is used as the source IP address when MAC frames are encapsulated and sent over the network. You can have multiple VMkernel NICs (also referred to as virtual network adapters or vmknics) per VEM that are used as sources for this encapsulated traffic. The encapsulation carries the 24-bit VXLAN identifier that scopes the MAC address of the payload frame.
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VMkernel NICs are used to manage physical NICs (pNICs) on a host server to connect the virtual network to the physical network. |
The connected VXLAN is indicated within the port profile configuration of the virtual network interface card (vNIC) and is applied when the VM connects. Each VXLAN uses an assigned IP multicast group to carry broadcast traffic within the VXLAN segment.
In Cisco UCS Director, you can configure VXLANs on the Cisco Nexus 1000 switch.
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For more detailed information about VXLANs and configuration guidelines for VXLANs, see the Cisco NX-OS Software Configuration Guides. |