Virtual Device Identifier and Network Interface Name

Language:

When you add a virtual switch or virtual network device to a domain, you can specify its device number by setting the id property.

primary# ldm add-vsw [id=switch-id] vswitch-name domain-name
primary# ldm add-vnet [id=network-id] if-name vswitch-name domain-name

Each virtual switch and virtual network device of a domain has a unique device number that is assigned when the domain is bound. If a virtual switch or virtual network device was added with an explicit device number (by setting the id property), the specified device number is used. Otherwise, the system automatically assigns the lowest device number available. In that case, the device number assigned depends on how virtual switch or virtual network devices were added to the system. The device number eventually assigned to a virtual switch or virtual network device is visible in the output of the ldm list-bindings command when a domain is bound.

The following example shows that the primary domain has one virtual switch, primary-vsw0. This virtual switch has a device number of 0 (switch@0).

primary# ldm list-bindings primary
...
VSW
    NAME         MAC               NET-DEV DEVICE   DEFAULT-VLAN-ID PVID VID MTU MODE
    primary-vsw0 00:14:4f:fb:54:f2 net0    switch@0 1               1    5,6 1500
...

The following example shows that the ldg1 domain has two virtual network devices: vnet and vnet1. The vnet device has a device number of 0 (network@0) and the vnet1 device has a device number of 1 (network@1).

primary# ldm list-bindings ldg1
...
NETWORK
    NAME  SERVICE              DEVICE    MAC               MODE   PVID VID MTU
    vnet  primary-vsw0@primary network@0 00:14:4f:fb:e0:4b hybrid 1        1500
    ...
    vnet1 primary-vsw0@primary network@1 00:14:4f:f8:e1:ea        1        1500
...

Similarly, when a domain with a virtual network device is running the Oracle Solaris OS, the virtual network device has a network interface, vnetN. However, the network interface number of the virtual network device, N, is not necessarily the same as the device number of the virtual network device, n.

Note - On Oracle Solaris 11 systems, generic link names in the form of netn are assigned to both vswn and vnetn. Use the dladm show-phys command to identify which netn names map to the vswn and vnetn devices.

Caution - The Oracle Solaris OS preserves the mapping between the name of a network interface and a virtual switch or a virtual network device based on the device number. If a device number is not explicitly assigned to a virtual switch or virtual network device, its device number can change when the domain is unbound and is later bound again. In that case, the network interface name assigned by the OS running in the domain can also change and make the existing system configuration unusable. This situation might happen, for example, when a virtual switch or a virtual network interface is removed from the configuration of the domain.

You cannot use the ldm list-* commands to directly determine the Oracle Solaris OS network interface name that corresponds to a virtual switch or virtual network device. However, you can obtain this information by using a combination of the output from ldm list -l command and from the entries under /devices on the Oracle Solaris OS.