Connectivity Guide

Virtual extensible
LAN (VXLAN)
A type of network virtualization overlay that encapsulates a tenant's payload into IP UDP packets for transport
across the IP underlay network.
VXLAN network
identier (VNI)
A 24-bit ID number that identies a tenant segment and is transmitted in a VXLAN encapsulated packet.
VXLAN tunnel
endpoint (VTEP)
A switch with connected end hosts that are assigned to virtual networks, and the virtual networks are mapped to
VXLAN segments. Local and remote VTEPs performs encapsulation and de-capsulation of VXLAN headers for the
trac between end hosts. A VTEP is sometimes referred to as a network virtualization edge (NVE) node.
Bridge domain A Layer 2 domain that receives packets from member interfaces and forwards or oods them to other member
interfaces based on a packet's destination MAC address. OS10 supports two types of bridge domains: simple
VLAN and virtual network.
• Simple VLAN: A bridge domain represented by a VLAN ID. Trac on all member ports are assigned with the
same VLAN ID.
• Virtual network: A bridge domain represented by a virtual network ID (VNID). A virtual network supports
overlay encapsulation and is mapped with either a single VLAN ID in a switch-scoped VLAN or with multiple
(Port,VLAN) pairs in a port-scoped VLAN.
Virtual network In OS10, each Layer 2 ooding domain in the overlay network is represented as a virtual network.
Virtual network
identier (VNID)
A 16-bit ID number that identies a virtual network in OS10.
Access port A port on a VTEP switch that connects to an end host and is part of the overlay network.
Network port A port on a VTEP switch that connects to the underlay network.
Switch-scoped
VLAN
A VLAN that is mapped to a virtual network ID (VNID) in OS10. All member ports of the VLAN are automatically
added to the virtual network.
• You can map only one VLAN ID to a virtual network.
• Ideally suited for existing tenant VLANs that need to stretch over an IP fabric using VXLAN
Port-scoped VLAN A Port,VLAN pair that is mapped to a virtual network ID (VNID) in OS10. You can assign an individual member
interface to a virtual network either with an associated tagged VLAN or as an untagged member. Using a port-
scoped VLAN, you can congure:
• The same VLAN ID on dierent access interfaces to dierent virtual networks.
• Dierent VLAN IDs on dierent access interfaces to the same virtual network.
VXLAN as NVO solution
Network virtualization overlay (NVO) is a solution designed to address the requirements of a multi-tenant data center, especially one with
virtualized hosts. An NVO network is an overlay network used to extend L2 connectivity among VMs belonging to a tenant segment over
an underlay IP network. Each tenant's payload is encapsulated in an IP packet at the originating VTEP and stripped of the encapsulation at
the destination VTEP to access the payload. Each tenant segment is called a virtual-network and is uniquely identied in OS10 using a
virtual network ID (VNID).
VXLAN is a type of encapsulation that is used as an NVO solution. VXLAN encapsulates a tenant's payload into IP UDP packets for
transport across the IP underlay network. In OS10, each virtual network is assigned a 24-bit number called a VXLAN network identier
(VNI) that is carried in the VXLAN-encapsulated packet. The VNI uniquely identies the tenant segment on all VTEPs. OS10 sets up ASIC
tables to:
• Enable the creation of a Layer 2 bridge ooding domain across a Layer 3 network.
• Facilitate packet forwarding between local ports and tunneling packets from the local to a remote device.
VXLAN
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