[SOLVED]Enabling VLAN tagging on Redhat Linux

14:49 21/05/2015
#HowTo: Configure Linux Virtual Local Area Network (VLAN)
#########################################################

#I needed a physical machine with one NIC to be able to have two different IP addresses on two different VLAN’s.

#This is the scenario:
######################
+++One network card with an IP of 192.168.10.1 (VLAN 10).
+++I needed another interface on the same physical NIC with an IP address of 192.168.20.x (VLAN 20).

#First you copy the network configuration
#cp /etc/sysconfig/network-scripts/ifcfg-eth0 /etc/sysconfig/network-scripts/ifcfg-eth0.10

#My original file looked like this:
    DEVICE=eth0
    ONBOOT=yes
    BOOTPROTO=none
    NETMASK=255.255.255.0
    IPADDR=192.168.10.1
    USERCTL=no
    PEERDNS=yes
    TYPE=Ethernet
    IPV6INIT=no

#I needed to add in the VLAN info and change the device name (add VLAN=yes)
    DEVICE=eth0.10
    ONBOOT=yes
    VLAN=yes
    BOOTPROTO=none
    NETMASK=255.255.255.0
    IPADDR=192.168.10.1
    USERCTL=no
    PEERDNS=yes
    TYPE=Ethernet
    IPV6INIT=no
   
#I then copied the file again to my second interface
cp /etc/sysconfig/network-scripts/ifcfg-eth0.10 /etc/sysconfig/network-scripts/ifcfg-eth0.20
#and changed the IP address and device name
    DEVICE=eth0.20
    ONBOOT=yes
    VLAN=yes
    BOOTPROTO=none
    NETMASK=255.255.255.0
    IPADDR=192.168.20.1
    USERCTL=no
    PEERDNS=yes
    TYPE=Ethernet
    IPV6INIT=no

#I then removed the original IP address information from
#nano /etc/sysconfig/network-scripts/ifcfg-eth0
    DEVICE=eth0
    ONBOOT=yes
    BOOTPROTO=none
    USERCTL=no
    PEERDNS=yes
    TYPE=Ethernet
    IPV6INIT=no

    (OLD VALUE):
    #My original file looked like this:
    DEVICE=eth0
    ONBOOT=yes
    BOOTPROTO=none
    NETMASK=255.255.255.0 #remove
    IPADDR=192.168.10.1   #remove
    USERCTL=no
    PEERDNS=yes
    TYPE=Ethernet
    IPV6INIT=no

#And restart the network service
service network restart

#Of course the configuration has to be done as well on the switch side as well to allow the trunk of both VLAN’s
Switch#(config)interface Gi3/41
Switch#(config-if)no switchport mode access
Switch#(config-if)switchport mode trunk
Switch#(config-if)switchport trunk allowed vlan 10,20

#Source: http://technodrone.blogspot.com/2011/10/enabling-vlan-tagging-on-redhat-linux.html
#        http://www.cyberciti.biz/tips/howto-configure-linux-virtual-local-area-network-vlan.html

#Using the vconfig command
#The vconfig program allows you to create and remove vlan-devices on a vlan enabled kernel. Vlan-devices are virtual Ethernet devices which represents the virtual lans on the physical lan. This is yet another method of configuring VLAN. To add VLAN ID 5 with following command for eth0 interface:
vconfig add eth0 5