1Virtual eXtensible Local Area Networking documentation 2====================================================== 3 4The VXLAN protocol is a tunnelling protocol designed to solve the 5problem of limited VLAN IDs (4096) in IEEE 802.1q. With VXLAN the 6size of the identifier is expanded to 24 bits (16777216). 7 8VXLAN is described by IETF RFC 7348, and has been implemented by a 9number of vendors. The protocol runs over UDP using a single 10destination port. This document describes the Linux kernel tunnel 11device, there is also a separate implementation of VXLAN for 12Openvswitch. 13 14Unlike most tunnels, a VXLAN is a 1 to N network, not just point to 15point. A VXLAN device can learn the IP address of the other endpoint 16either dynamically in a manner similar to a learning bridge, or make 17use of statically-configured forwarding entries. 18 19The management of vxlan is done in a manner similar to its two closest 20neighbors GRE and VLAN. Configuring VXLAN requires the version of 21iproute2 that matches the kernel release where VXLAN was first merged 22upstream. 23 241. Create vxlan device 25 # ip link add vxlan0 type vxlan id 42 group 239.1.1.1 dev eth1 dstport 4789 26 27This creates a new device named vxlan0. The device uses the multicast 28group 239.1.1.1 over eth1 to handle traffic for which there is no 29entry in the forwarding table. The destination port number is set to 30the IANA-assigned value of 4789. The Linux implementation of VXLAN 31pre-dates the IANA's selection of a standard destination port number 32and uses the Linux-selected value by default to maintain backwards 33compatibility. 34 352. Delete vxlan device 36 # ip link delete vxlan0 37 383. Show vxlan info 39 # ip -d link show vxlan0 40 41It is possible to create, destroy and display the vxlan 42forwarding table using the new bridge command. 43 441. Create forwarding table entry 45 # bridge fdb add to 00:17:42:8a:b4:05 dst 192.19.0.2 dev vxlan0 46 472. Delete forwarding table entry 48 # bridge fdb delete 00:17:42:8a:b4:05 dev vxlan0 49 503. Show forwarding table 51 # bridge fdb show dev vxlan0 52