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- Virtual eXtensible Local Area Networking documentation
- ======================================================
- The VXLAN protocol is a tunnelling protocol designed to solve the
- problem of limited VLAN IDs (4096) in IEEE 802.1q. With VXLAN the
- size of the identifier is expanded to 24 bits (16777216).
- VXLAN is described by IETF RFC 7348, and has been implemented by a
- number of vendors. The protocol runs over UDP using a single
- destination port. This document describes the Linux kernel tunnel
- device, there is also a separate implementation of VXLAN for
- Openvswitch.
- Unlike most tunnels, a VXLAN is a 1 to N network, not just point to
- point. A VXLAN device can learn the IP address of the other endpoint
- either dynamically in a manner similar to a learning bridge, or make
- use of statically-configured forwarding entries.
- The management of vxlan is done in a manner similar to its two 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 link add vxlan0 type vxlan id 42 group 239.1.1.1 dev eth1 dstport 4789
- This creates a new device named vxlan0. The device uses the multicast
- group 239.1.1.1 over eth1 to handle traffic for which there is no
- entry in the forwarding table. The destination port number is set to
- the IANA-assigned value of 4789. The Linux implementation of VXLAN
- pre-dates the IANA's selection of a standard destination port number
- and uses the Linux-selected value by default to maintain backwards
- compatibility.
- 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
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