AS5800-EC Series CLI Reference Guide R02

Chapter 19 | VLAN Commands
Configuring VxLAN Tunneling
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show
l2protocol-tunnel
This command shows settings for Layer 2 Protocol Tunneling (L2PT).
Command Mode
Privileged Exec
Example
Console#show l2protocol-tunnel
Layer 2 Protocol Tunnel
Tunnel MAC Address : 01-12-CF-00-00-00
Interface Protocol
----------------------------------------------------------
Eth 1/ 1 Spanning Tree
Console#
Configuring VxLAN Tunneling
This section describes the commands used to configure Virtual Extensible LAN
(VxLAN) tunneling.
VxLAN is a networking scheme that encapsulates MAC-based Layer 2 Ethernet
frames within Layer 3 UDP packets to aggregate and tunnel multiple layer 2
networks across a Layer 3 infrastructure. VxLAN scales up to 16 million logical
networks and supports Layer 2 adjacency for isolated tenants across IP networks.
Multicast transmission is used for broadcast, multicast, and unknown unicast traffic.
In this implementation, broadcast, multicast and unknown unicast traffic can also
use unicast tunneling.
When a packet enters a switch port, the switch determines if the VLAN to which this
port belongs is associated with a VxLAN ID. If a VLAN to VXLAN mapping is found, it
then searches the bridge table for the destination port. If the egress port is found,
the packet is encapsulated with a VxLAN header and sent on to the corresponding
Virtual Tunnel End Point (VTEP). If the egress port is not found, the packet is flooded
to all VTEPs on this VXLAN ID. The flooded packet may be encapsulated as a unicast
packet or multicast packet according to the configured setting as described in RFC
7348.
Unicast VM-to-VM Communication
Consider a Virtual Machine (VM) within a VXLAN overlay network. To communicate
with a VM on a different host, it sends a MAC frame destined to the target as it
normally would. The VTEP on the physical host looks up the Virtual Network
Identifier (VNI) to which this VM is associated. It then determines if the destination
MAC is on the same segment and if there is a mapping of the destination MAC
address to the remote VTEP. If so, an outer header comprising an outer MAC, outer
IP header, and VXLAN header are prepended to the original MAC frame. The
encapsulated packet is forwarded towards the remote VTEP. Upon reception, the
remote VTEP verifies the validity of the VNI and whether or not there is a VM on that
VNI using a MAC address that matches the inner destination MAC address. If so, the