Virtual Extensible LAN (VXLAN) is a
network virtualization technology that attempts to address the
scalability problems associated with large
cloud computing deployments. It uses a
VLAN-like encapsulation technique to encapsulate
OSI layer 2 Ethernet frames within
layer 4 UDP datagrams, using 4789 as the default
IANA
The Internet Assigned Numbers Authority (IANA) is a standards organization that oversees global IP address allocation, autonomous system number allocation, root zone management in the Domain Name System (DNS), media types, and other Interne ...
-assigned destination UDP port number. VXLAN endpoints, which terminate VXLAN tunnels and may be either virtual or physical
switch ports, are known as VXLAN tunnel endpoints (VTEPs).
VXLAN is an evolution of efforts to standardize on an overlay encapsulation protocol. Compared to VLAN which provides limited number of layer-2 VLANs (typically using 12-bit VLAN ID), VXLAN increases scalability up to 16 million logical networks (with 24-bit VNID) and allows for layer-2 adjacency across IP networks.
Multicast or
unicast with head-end replication (HER) is used to flood
Broadcast, unknown-unicast and multicast traffic.
The VXLAN specification was originally created by
VMware,
Arista Networks and
Cisco. Other backers of the VXLAN technology include
Huawei,
Broadcom,
Citrix,
Pica8, Big Switch Networks,
Cumulus Networks,
Dell EMC,
Ericsson,
Mellanox,
FreeBSD
FreeBSD is a free and open-source Unix-like operating system descended from the Berkeley Software Distribution (BSD), which was based on Research Unix. The first version of FreeBSD was released in 1993. In 2005, FreeBSD was the most popular ...
,
OpenBSD
OpenBSD is a security-focused, free and open-source, Unix-like operating system based on the Berkeley Software Distribution (BSD). Theo de Raadt created OpenBSD in 1995 by forking NetBSD 1.0. According to the website, the OpenBSD project em ...
,
Red Hat
Red Hat, Inc. is an American software company that provides open source software products to enterprises. Founded in 1993, Red Hat has its corporate headquarters in Raleigh, North Carolina, with other offices worldwide.
Red Hat has become ass ...
,
, and
Juniper Networks.
VXLAN is officially documented by the IETF in RFC 7348.
VXLAN encapsulates a
MAC frame in a
UDP datagram for transport across an IP network,
creating an
overlay network or
tunnel.
Open vSwitch is an example of a software-based virtual
network switch that supports VXLAN overlay networks.
See also
*
Distributed Overlay Virtual Ethernet (DOVE)
*
Ethernet VPN (EVPN)
*
GENEVE, an industry effort to unify both VXLAN and NVGRE technologies
*
Generic Routing Encapsulation (GRE)
*
IEEE 802.1ad, an Ethernet networking standard, also known as provider bridging, Stacked VLANs, or simply QinQ.
*
NVGRE, a similar competing specification
*
Overlay Transport Virtualization (OTV)
*
Virtual LAN (VLAN)
*
Layer 2 Tunneling Protocol (L2TP)
References
External links
VXLAN Deep Dive: Part 1an
Part 2 November 2012, by Joe Onisick
Tunneling protocols
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