OpenCloudOS-Kernel/Documentation/networking/vxlan.txt

Virtual eXtensible Local Area Networking documentation
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The VXLAN protocol is a tunnelling protocol that is designed to
solve the problem of limited number of available VLAN's (4096).
With VXLAN identifier is expanded to 24 bits.

It is a draft RFC standard, that is implemented by Cisco Nexus,
Vmware and Brocade. The protocol runs over UDP using a single
destination port (still not standardized by IANA).
This document describes the Linux kernel tunnel device,
there is also an implantation of VXLAN for Openvswitch.

Unlike most tunnels, a VXLAN is a 1 to N network, not just point
to point. A VXLAN device can either dynamically learn the IP address
of the other end, in a manner similar to a learning bridge, or the
forwarding entries can be configured statically.

The management of vxlan is done in a similar fashion to it's
too closest neighbors GRE and VLAN. Configuring VXLAN requires
the version of iproute2 that matches the kernel release
where VXLAN was first merged upstream.

1. Create vxlan device
  # ip li add vxlan0 type vxlan id 42 group 239.1.1.1 dev eth1

This creates a new device (vxlan0). The device uses the
the multicast group 239.1.1.1 over eth1 to handle packets where
no entry is in the forwarding table.

2. Delete vxlan device
  # ip link delete vxlan0

3. Show vxlan info
  # ip -d link show vxlan0

It is possible to create, destroy and display the vxlan
forwarding table using the new bridge command.

1. Create forwarding table entry
  # bridge fdb add to 00:17:42:8a:b4:05 dst 192.19.0.2 dev vxlan0

2. Delete forwarding table entry
  # bridge fdb delete 00:17:42:8a:b4:05 dev vxlan0

3. Show forwarding table
  # bridge fdb show dev vxlan0