11.6 Configuring VLANs with Untagged Data Frames

The software described in this documentation is either in Extended Support or Sustaining Support. See https://www.oracle.com/us/support/library/enterprise-linux-support-policies-069172.pdf for more information.
Oracle recommends that you upgrade the software described by this documentation as soon as possible.

11.6 Configuring VLANs with Untagged Data Frames

11.6.1 Using vconfig to Create VLAN Devices

A virtual local area network (VLAN) consists of a group of machines that can communicate as if they were attached to the same physical network. A VLAN allows you to group systems regardless of their actual physical location on a LAN. In a VLAN that uses untagged data frames, you create the broadcast domain by assigning the ports of network switches to the same permanent VLAN ID or PVID (other than 1, which is the default VLAN). All ports that you assign with this PVID are in a single broadcast domain. Broadcasts between devices in the same VLAN are not visible to other ports with a different VLAN, even if they exist on the same switch.

To create a VLAN device for a network interface or bonded interface:

Create a file named ifcfg-interface.pvid in the /etc/sysconfig/network-scripts directory, by copying the ifcfg-interface configuration file for the interface that is connected to a port that implements the PVID that is identified by pvid.
For example, if the PVID of the switch port is 5 and the interface connected to it is eth0, copy the ifcfg-eth0 file to ifcfg-eth0.5:
```
# cd /etc/sysconfig/network-scripts
# cp ifcfg-eth0 ifcfg-eth0.5
```
For the bonded interface bond0, where the PVID of the connected switch ports is 10, copy the ifcfg-bond0 file to ifcfg-bond0.10:
```
# cd /etc/sysconfig/network-scripts
# cp ifcfg-bond0 ifcfg-bond0.10
```
Note
You do not need to create virtual interfaces for the component interfaces of the bonded interface. However, you must set the PVID on each switch port to which they connect.

Edit the ifcfg-interface.pvid file, change the DEVICE (and NAME, if specified) entries, and add a VLAN=yes entry. For example, ifcfg-eth0.5 would appear similar to the following:

DEVICE="eth0.5"
NAME="System eth0.5"
VLAN=yes
IPADDR=192.168.1.101
NETMASK=255.255.255.0
BROADCAST=192.0.2.255
NM_CONTROLLED="yes"
ONBOOT=yes
USERCTL=no
TYPE=Ethernet
BOOTPROTO=none
DEFROUTE=yes
IPV4_FAILURE_FATAL=yes
IPV6INIT=no
PEERDNS=yes
PEERROUTES=yes

and ifcfg-bond0.10 as:

DEVICE="bond0.10"
VLAN=yes
IPADDR=192.168.1.121
NETMASK=255.255.255.0
NETWORK=192.168.1.0
BROADCAST=192.168.1.255
ONBOOT=yes
BOOTPROTO=none
USERCTL=no
TYPE=Ethernet

Save your changes to the file. Do not edit the original ifcfg-ethN file.

Restart the network:
```
# service network restart
```
In addition to the regular interface, eth0 or bond0, which uses the physical LAN, you now have a VLAN device, such as eth0.5 or bond0.10, which can use untagged frames to access the virtual LAN.
To obtain detailed information about VLAN interfaces, view the /proc/net/vlan directory.