Virtual Network Definition File 4.0

This page describes how to define a new Virtual Network template. A Virtual Network template follows the same syntax as the VM template.

If you want to learn more about the Virtual Network management, you can do so here.

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Common Attributes

There are two types of Virtual Networks, ranged and fixed. Their only difference is how the leases are defined in the template.

These are the common attributes for both types of VNets:

Attribute Value Description Mandatory
NAME String Name of the Virtual Network YES
BRIDGE String Name of the physical bridge in the physical host where the VM should connect its network interface YES if PHYDEV is not set
TYPE RANGED/FIXED Type of this VNet YES
VLAN YES/NO Whether or not to isolate this virtual network using the Virtual Network Manager drivers. If omitted, the default value is NO. NO
VLAN_ID Integer Optional VLAN id for the 802.1Q and Open vSwitch networking drivers. NO
PHYDEV String Name of the physical network device that will be attached to the bridge. YES for 802.1Q driver
SITE_PREFIX String IPv6 unicast local addresses (ULAs). Must be a valid IPv6 Optional
GLOBAL_PREFIX String IPv6 global unicast addresses. Must be a valid IPv6 Optional

Please note that any arbitrary value can be set in the Virtual Network template, and then used in the contextualization section of the VM. For instance, NETWORK_GATEWAY=“x.x.x.x” might be used to define the Virtual Network, and then used in the context section of the VM to configure its network to connect through the GATEWAY.

If you need OpenNebula to generate IPv6 addresses, that can be later used in context or for Virtual Router appliances, you can use the GLOBAL_PREFIX and SITE_PREFIX attributes

Attributes Used for Contextualization

Attribute Description
NETWORK_ADDRESS Base network address
NETWORK_MASK Network mask
GATEWAY Router for this network, do not set when the network is not routable
DNS Specific DNS for this network
GATEWAY6 IPv6 router for this network
CONTEXT_FORCE_IPV4 When a vnet is IPv6 the IPv4 is not configured unless this attribute is set

Leases

A lease is a definition of an IP-MAC pair. From an IP address, OpenNebula generates an associated MAC using the following rule: MAC = MAC_PREFFIX:IP. All Virtual Networks share a default value for the MAC_PREFIX, set in the oned.conf file.

So, for example, from IP 10.0.0.1 and MAC_PREFFIX 02:00, we get 02:00:0a:00:00:01.

The available leases for new VNets are defined differently for each type.

Fixed Virtual Networks

Fixed VNets need a series of LEASES vector attributes, defined with the following sub-attributes:

Sub-Attribute Value Description Mandatory
IP IP address IP for this lease YES
MAC MAC address MAC associated to this IP NO

:!: The optional MAC attribute will overwrite the default MAC_PREFIX:IP rule. Be aware that this will break the default contextualization mechanism.

Ranged Virtual Networks

Instead of a list of LEASES, ranged Virtual Networks contain a range of IPs that can be defined in a flexible way using these attributes:

Attribute Value Description
NETWORK_ADDRESS IP address, optionally in CIDR notation Base network address to generate IP addresses.
NETWORK_SIZE A, B, C, or Number Number of VMs that can be connected using this network. It can be defined either using a number or a network class (A, B or C). The default value for the network size can be found in oned.conf.
NETWORK_MASK Mask in dot-decimal notation Network mask for this network.
IP_START IP address First IP of the range.
IP_END IP address Last IP of the range.
MAC_START MAC address First MAC of the range.

The following examples define the same network range, from 10.10.10.1 to 10.10.10.254: 

NETWORK_ADDRESS = 10.10.10.0
NETWORK_SIZE    = C
NETWORK_ADDRESS = 10.10.10.0
NETWORK_SIZE    = 254
NETWORK_ADDRESS = 10.10.10.0/24
NETWORK_ADDRESS = 10.10.10.0
NETWORK_MASK    = 255.255.255.0

You can change the first and/or last IP of the range: 

NETWORK_ADDRESS = 10.10.10.0/24
IP_START        = 10.10.10.17

Or define the range manually: 

IP_START        = 10.10.10.17
IP_END          = 10.10.10.41

Finally, you can define the network by just specifying the MAC address set (specially in IPv6). The following is equivalent to the previous examples but with MACs: 

MAC_START    = 02:00:0A:0A:0A:11
NETWORK_SIZE = 254

:!: With either of the above procedures, no matter if you are defining the set using IPv4 networks, OpenNebula will generate IPv6 addresses if the GLOBAL_PREFIX and/or SITE_PREFIX is added to the network template. Note that the link local IPv6 address will be always generated.

Examples

Sample fixed VNet: 

NAME    = "Blue LAN"
TYPE    = FIXED
 
# We have to bind this network to ''virbr1'' for Internet Access
BRIDGE  = vbr1
 
LEASES  = [IP=130.10.0.1]
LEASES  = [IP=130.10.0.2, MAC=50:20:20:20:20:21]
LEASES  = [IP=130.10.0.3]
LEASES  = [IP=130.10.0.4]
 
# Custom Attributes to be used in Context
GATEWAY = 130.10.0.1
DNS     = 130.10.0.1
 
LOAD_BALANCER = 130.10.0.4

Sample ranged VNet: 

NAME    = "Red LAN"
TYPE    = RANGED
 
# Now we'll use the host private network (physical)
BRIDGE  = vbr0
 
NETWORK_ADDRESS = 192.168.0.0/24
IP_START        = 192.168.0.3
 
# Custom Attributes to be used in Context
GATEWAY = 192.168.0.1
DNS     = 192.168.0.1
 
LOAD_BALANCER = 192.168.0.2