A network switch capable of forwarding VLAN tagged traffic. The physical switch ports should be VLAN trunks.

This driver requires some previous work on the network components, namely the switches, to enable VLAN trunking in the network interfaces connected to the OpenNebula hosts. If this is not activated the VLAN tags will not get trough and the network will behave erratically.

In OpenNebula 3.0, this functionality was provided through a hook, and it wasn't effective after a migration. Since OpenNebula 3.2 this limitation does not apply.

• The sudoers file must be configured so oneadmin can execute vconfig, brctl and ip in the hosts.
• The package vconfig must be installed in the hosts.
• Hosts must have the module 8021q loaded.

To enable VLAN (802.1Q) support in the kernel, one must load the 8021q module: <xterm> $ modprobe 8021q </xterm>

If the module is not available, please refer to your distribution's documentation on how to install it. This module, along with the vconfig binary which is also required by the script, is generally supplied by the vlan package.

To enable this driver, use 802.1Q as the Virtual Network Manager driver parameter when the hosts are created with the onehost command:

<xterm> $ onehost create host01 im_kvm vmm_kvm tm_shared 802.1Q </xterm>

The driver will be automatically applied to every Virtual Machine deployed in the Host. However, this driver requires a special configuration in the Virtual Network template: only the virtual networks with the attribute VLAN set to YES will be isolated. The attribute PHYDEV must be also defined, with the name of the physical network device that will be attached to the bridge. The BRIDGE attribute is not mandatory, if it isn't defined, OpenNebula will generate one automatically.

NAME    = "hmnet"
TYPE    = "fixed"
 
PHYDEV  = "eth0"
VLAN    = "YES"
VLAN_ID = 50        # optional
BRIDGE  = "brhm"    # optional
 
LEASES = ...

In this scenario, the driver will check for the existence of the brhm bridge. If it doesn't exist it will be created. eth0 will be tagged (eth0.<vlan_id>) and attached to brhm (unless it's already attached).

Any user with Network creation/modification permissions may force a custom vlan id with the VLAN_ID parameter in the network template. In that scenario, any user may be able to connect to another network with the same network id. Techniques to avoid this are explained under the Tuning & Extending section.

The vlan id is calculated by adding the network id to a constant defined in /var/lib/one/remotes/vnm/OpenNebulaNetwork.rb. You can customize that value to your own needs:

CONF = {
    :start_vlan => 2
}

You can either restrict permissions on Network creation with ACL rules, or you can entirely disable the possibility to redefine the VLAN_ID by modifying the source code of /var/lib/one/remotes/vnm/802.1Q/HostManaged.rb. Change these lines:

                if nic[:vlan_id]
                    vlan = nic[:vlan_id]
                else
                    vlan = CONF[:start_vlan] + nic[:network_id].to_i
                end

with this one:

                vlan = CONF[:start_vlan] + nic[:network_id].to_i