Configuring VLAN interfaces in Linux

In this post, we will see how to configure VLAN tagged interfaces on a Linux machine. This will allow you to connect your machine to different VLANs in your network using a single interface. In this example, am going to configure the VLAN tagging on the network card interface directly. If you want reduntancy in the network level, it is recommended to configure bonding and then configure VLAN taggging on that bonded interface. Based on the bonding parameter configured, you can make the bond work in active-standby mode / link aggregation / active-active or so…

In this example, am having an interface eth0 configured with IP 192.168.0.1. Now, i need to configure 2 VLAN tagged interfaces for VLAN 10 & 20. The VLAN 10 interface should be assigned an IP 192.168.10.1 & VLAN 20 with IP 192.168.20.1. The interface configuration file is as follows:


#more /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
ONBOOT=yes
BOOTPROTO=none
NETMASK=255.255.255.0
IPADDR=192.168.0.1
USERCTL=no
PEERDNS=yes
TYPE=Ethernet
IPV6INIT=no

Creating VLAN 10 tagged interface:

To configure a VLAN tagged interface with VLAN_ID 10, copy the ifcfg-eth0 file and make ifcfg-eth0.10 first.

# cp /etc/sysconfig/network-scripts/ifcfg-eth0 /etc/sysconfig/network-scripts/ifcfg-eth0.10

 

Now edit the contents as follows. Dont forget to add the entry VLAN=yes in the VLAN tagged interface configuration file.


#more /etc/sysconfig/network-scripts/ifcfg-eth0.10
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

Creating VLAN 20 Tagged interface:

Copy the VLAN 10 interface configuration file to VLAN 20 interface configuration file.


#cp /etc/sysconfig/network-scripts/ifcfg-eth0.10 /etc/sysconfig/network-scripts/ifcfg-eth0.20

Edit the ifcfg-eth0.20 file and should look the following:

#more /etc/sysconfig/network-scripts/ifcfg-eth0.20
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

Restart the network service now

#service network restart

Switch Level Configuration:

For the VLAN interfaces to communicate through the switch, the switch port to which we connect the server interface should be configured as a trunk port. This is to be done in the network switch level. The interface fastethernet 0/2 here represents the interface in the swithc to which the server is connected. You may have to replace the interface type and numbers according to your physical connectivity.

Switch#(config)interface fastethernet 0/2
Switch#(config-if)no switchport mode access
Switch#(config-if)switchport mode trunk
Switch#(config-if)switchport trunk allowed vlan 0,10,20

Configuring VLAN tagged interfaces using vconfig command

We can configure VLAN interfaces using vconfig command also. This configuration is a temporary one and will be lost after a reboot.

To add a VLAN 10 tagged interface, use the following command:

#vconfig add eth0 10

Use ifconfig to assign IP address to vlan interface :

# ifconfig eth0.10 192.168.10.1 netmask 255.255.255.0 broadcast 192.168.1.255 up

Get detailed information about VLAN interface:

# cat /proc/net/vlan/eth0.5

Get the VLAN interface information on the server

#cat /proc/net/vlan/config

If you wish to delete VLAN interface delete command

# ifconfig eth0.5 down
# vconfig rem eth0.5


source: https://sysadmincorner.wordpress.com/2012/04/06/configuring-vlan-interfaces-in-linux/#more-41
Attachments
There are no attachments for this article.
Related Articles RSS Feed
Secure Secure Shell
Viewed 7986 times since Fri, Aug 21, 2020
Linux 20 Netstat Commands for Linux Network Management
Viewed 7932 times since Mon, Sep 21, 2020
Linux - How to monitor CPU usage
Viewed 4609 times since Fri, Jun 8, 2018
RHEL: ACLs basics
Viewed 2213 times since Sun, May 27, 2018
12 Linux Rsync Options in Linux Explained
Viewed 9685 times since Wed, Oct 31, 2018
How do I add ethtool settings to a network device permanently?
Viewed 4756 times since Mon, May 21, 2018
Using etckeeper with git
Viewed 5293 times since Sun, Jun 3, 2018
Linux - How to get Memory information
Viewed 888 times since Fri, Jun 8, 2018
20 Linux YUM (Yellowdog Updater, Modified) Commands for Package Management YUM
Viewed 9811 times since Thu, Oct 25, 2018
chrt command: Set / Manipulate Real Time Attributes of a Linux Process
Viewed 9316 times since Mon, Feb 17, 2020