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d342894c | 1 | Virtual eXtensible Local Area Networking documentation |
2 | ====================================================== | |
3 | ||
e8fed985 RJ |
4 | The VXLAN protocol is a tunnelling protocol designed to solve the |
5 | problem of limited VLAN IDs (4096) in IEEE 802.1q. With VXLAN the | |
6 | size of the identifier is expanded to 24 bits (16777216). | |
7 | ||
8 | VXLAN is described by IETF RFC 7348, and has been implemented by a | |
9 | number of vendors. The protocol runs over UDP using a single | |
10 | destination port. This document describes the Linux kernel tunnel | |
11 | device, there is also a separate implementation of VXLAN for | |
12 | Openvswitch. | |
13 | ||
14 | Unlike most tunnels, a VXLAN is a 1 to N network, not just point to | |
15 | point. A VXLAN device can learn the IP address of the other endpoint | |
16 | either dynamically in a manner similar to a learning bridge, or make | |
17 | use of statically-configured forwarding entries. | |
18 | ||
19 | The management of vxlan is done in a manner similar to its two closest | |
20 | neighbors GRE and VLAN. Configuring VXLAN requires the version of | |
21 | iproute2 that matches the kernel release where VXLAN was first merged | |
22 | upstream. | |
d342894c | 23 | |
24 | 1. Create vxlan device | |
e8fed985 RJ |
25 | # ip link add vxlan0 type vxlan id 42 group 239.1.1.1 dev eth1 dstport 4789 |
26 | ||
27 | This creates a new device named vxlan0. The device uses the multicast | |
28 | group 239.1.1.1 over eth1 to handle traffic for which there is no | |
29 | entry in the forwarding table. The destination port number is set to | |
30 | the IANA-assigned value of 4789. The Linux implementation of VXLAN | |
31 | pre-dates the IANA's selection of a standard destination port number | |
32 | and uses the Linux-selected value by default to maintain backwards | |
33 | compatibility. | |
d342894c | 34 | |
35 | 2. Delete vxlan device | |
36 | # ip link delete vxlan0 | |
37 | ||
38 | 3. Show vxlan info | |
cc9b3101 | 39 | # ip -d link show vxlan0 |
d342894c | 40 | |
41 | It is possible to create, destroy and display the vxlan | |
42 | forwarding table using the new bridge command. | |
43 | ||
44 | 1. Create forwarding table entry | |
45 | # bridge fdb add to 00:17:42:8a:b4:05 dst 192.19.0.2 dev vxlan0 | |
46 | ||
47 | 2. Delete forwarding table entry | |
cc9b3101 | 48 | # bridge fdb delete 00:17:42:8a:b4:05 dev vxlan0 |
d342894c | 49 | |
50 | 3. Show forwarding table | |
51 | # bridge fdb show dev vxlan0 |