----
+
+VLAN 802.1Q
+~~~~~~~~~~~
+
+A virtual LAN (VLAN) is a broadcast domain that is partitioned and
+isolated in the network at layer two. So it is possible to have
+multiple networks (4096) in a physical network, each independent of
+the other ones.
+
+Each VLAN network is identified by a number often called 'tag'.
+Network packages are then 'tagged' to identify which virtual network
+they belong to.
+
+
+VLAN for Guest Networks
+^^^^^^^^^^^^^^^^^^^^^^^
+
+{pve} supports this setup out of the box. You can specify the VLAN tag
+when you create a VM. The VLAN tag is part of the guest network
+confinuration. The networking layer supports differnet modes to
+implement VLANs, depending on the bridge configuration:
+
+* *VLAN awareness on the Linux bridge:*
+In this case, each guest's virtual network card is assigned to a VLAN tag,
+which is transparently supported by the Linux bridge.
+Trunk mode is also possible, but that makes the configuration
+in the guest necessary.
+
+* *"traditional" VLAN on the Linux bridge:*
+In contrast to the VLAN awareness method, this method is not transparent
+and creates a VLAN device with associated bridge for each VLAN.
+That is, if e.g. in our default network, a guest VLAN 5 is used
+to create eno1.5 and vmbr0v5, which remains until rebooting.
+
+* *Open vSwitch VLAN:*
+This mode uses the OVS VLAN feature.
+
+* *Guest configured VLAN:*
+VLANs are assigned inside the guest. In this case, the setup is
+completely done inside the guest and can not be influenced from the
+outside. The benefit is that you can use more than one VLAN on a
+single virtual NIC.
+
+
+VLAN on the Host
+^^^^^^^^^^^^^^^^
+
+To allow host communication with an isolated network. It is possible
+to apply VLAN tags to any network device (NIC, Bond, Bridge). In
+general, you should configure the VLAN on the interface with the least
+abstraction layers between itself and the physical NIC.
+
+For example, in a default configuration where you want to place
+the host management address on a separate VLAN.
+
+NOTE: In the examples we use the VLAN at bridge level to ensure the correct
+function of VLAN 5 in the guest network, but in combination with VLAN anwareness
+bridge this it will not work for guest network VLAN 5.
+The downside of this setup is more CPU usage.
+
+.Example: Use VLAN 5 for the {pve} management IP
+----
+auto lo
+iface lo inet loopback
+
+iface eno1 inet manual
+
+iface eno1.5 inet manual
+
+auto vmbr0v5
+iface vmbr0v5 inet static
+ address 10.10.10.2
+ netmask 255.255.255.0
+ gateway 10.10.10.1
+ bridge_ports eno1.5
+ bridge_stp off
+ bridge_fd 0
+
+auto vmbr0
+iface vmbr0 inet manual
+ bridge_ports eno1
+ bridge_stp off
+ bridge_fd 0
+
+----
+
+The next example is the same setup but a bond is used to
+make this network fail-safe.
+
+.Example: Use VLAN 5 with bond0 for the {pve} management IP
+----
+auto lo
+iface lo inet loopback
+
+iface eno1 inet manual
+
+iface eno2 inet manual
+
+auto bond0
+iface bond0 inet manual
+ slaves eno1 eno2
+ bond_miimon 100
+ bond_mode 802.3ad
+ bond_xmit_hash_policy layer2+3
+
+iface bond0.5 inet manual
+
+auto vmbr0v5
+iface vmbr0v5 inet static
+ address 10.10.10.2
+ netmask 255.255.255.0
+ gateway 10.10.10.1
+ bridge_ports bond0.5
+ bridge_stp off
+ bridge_fd 0
+
+auto vmbr0
+iface vmbr0 inet manual
+ bridge_ports bond0
+ bridge_stp off
+ bridge_fd 0
+
+----
+
////
TODO: explain IPv6 support?
TODO: explain OVS