Linux/Netzwerk/Konfiguration/vlan

vlan

Howto use vlan (dot1q, 802.1q, trunk)

Manual config

modprobe 8021q

apt install vlan

vconfig add eth0 222 # 222 is vlan number
ifconfig eth0.222 up
ifconfig eth0.222 mtu 1496 #optional if your network card doesn't support MTU 1504B
ifconfig eth0.222 10.10.10.1 netmask 255.255.255.0

Network init script config

Into /etc/modules add line:

8021q

In /etc/network/interfaces to section iface add parameter:

vlan-raw-device eth0

The interface name should be the raw interface name (the same as specified by vlan-raw-device), then a dot, then the VLAN ID, for example eth0.100. It can instead be "vlan" then the VLAN ID, for example vlan100. In either case, the VLAN ID is on the end, and this is the only place that it is configured.

Note: If you name your VLAN interfaces ethX.YYY, then there is no need to specify the vlan-raw-device, as the raw device can be retrieved from the interface name.

Eg:

auto eth0.222
iface eth0.222 inet static
 address 10.10.10.1/24
 vlan-raw-device eth0

Bridges and VLANs

If you create VLAN interfaces only to put them into a bridge, there is no need to define the VLAN interfaces manually. Just config the bridge, and the VLAN interface will be created automatically when creating the bridge, e.g:

auto br1
iface br1 inet manual
 bridge_ports eth0.99 eth1.99
 up /usr/sbin/brctl stp br1 on

Caveats when using bridging and vlan

#/etc/network/interfaces
auto eth0 bri0
iface eth0 inet static
 address 192.168.1.1/24
iface eth0.110 inet manual
 vlan-raw-device eth0
iface bri0 inet static
 address 192.168.110.1/24
 bridge_ports eth0.110
 bridge_stp on
 bridge_maxwait 10

If you are using a brigded VLAN setup, which is probably useful for networking in virtualization environments, take care to only attach either a bridge device or VLAN devices to an underlying physical device - like shown above. Attaching the physical interface (eth0) to a bridge (eg. bri1) while using the same physical interface on apparently different VLANs will result in all packets to remain tagged. (Kernel newer than 2.6.37 and older than 3.2).