802.1q VLAN HOWTO

from http://ubuntuforums.org/showthread.php?t=703387
=======================================================

Install the vlan package:

Code:

sudo apt-get install vlan

Load the 8021q kernel module:

Code:

sudo modprobe 8021q

Ensure that this module gets loaded after a reboot by adding to /etc/modules:

Code:

sudo  sh -c 'grep -q 8021q /etc/modules || echo 8021q >> /etc/modules'

Configure the interface by editing /etc/network/interfaces:

Code:

sudo vi /etc/network/interfaces

and adding a stanza like this:

Code:

auto eth0.99
iface eth0.99 inet static
address 192.168.99.1
netmask 255.255.255.0

Then bring the interface up:

Code:

sudo ifup eth0.99

========================================================================
goal: several vlan-interfaces on top of a bonding trunk

first step: create the bonding config

- in /etc/network/interfaces:

Code:

 #auto bond0
iface bond0 inet manual
 pre-up ip link set bond0 up
 up ifenslave bond0 eth0
 up ifenslave bond0 eth1
 post-down ifenslave -d bond0 eth0 eth1
 post-down modprobe  -r bond0

second step: define the logical network link (repeat as to your needs)

- in /etc/network/interfaces:

Code:

 auto bond0.911
 allow-hotplug bond0.911
 iface bond0.911 inet static
 address 10.20.50.18
 netmask 255.255.255.192
 network 10.20.50.0
 broadcast 10.20.50.63
 gateway 10.20.50.2
 pre-up /etc/network/bondingstate UP bond0 911
 post-down /etc/network/bondingstate DOWN bond0 911

third step: glue them together

- in /etc/network/bondingstate:

Code:

# Script /etc/network/bondingstate
# wird aufgerufen aus /etc/network/interfaces
# 04.09.2007, no copyright
#
 
# Variablen setzen

set -x
CHANGE_STATE=$1
TRUNK=$2
VLANID=$3

case $CHANGE_STATE in
  UP)
    #egrep "$TRUNK" /etc/network/run/ifstate >/dev/null 2>&1
    if [ ! -f /proc/net/bonding/$TRUNK ] ; then
      ifup $TRUNK
      if [ $? -ne 0 ] ; then
        exit 1
      fi
    fi
    vconfig add $TRUNK $VLANID
    ;;

  DOWN)
    vconfig rem $TRUNK.$VLANID
    egrep "$TRUNK\.[0-9]+" /etc/network/run/ifstate >/dev/null 2>&1
    if [ $? -ne 0 ] ; then
      if [ -z "$VLANID" ] ; then
        exit 0
      else
        ifdown $TRUNK
      fi
    fi
    ;;
esac

What happens:

'auto bond0.911' starts setting up the interface.
'pre-up' calls bondingstate
bondingstate tests whether the bonding module is loaded,
then starts bonding, if need be.
'iface bond0' enslaves the physical NICs, then returns success
bondingstate adds the given vlan ID and returns success
'auto bond0.911' configures IP-addresses and returns success

Configuring additional links is but a copy of 'bond0.911'

On shutdown, 'post-down /etc/network/bondingstate DOWN bond0 911'
calls bondingstate, which in turn checks in /etc/network/run/ifstate
whether this is the last vlan interface and if so, shuts down bond0
bond0's post-down then will remove the kernel module

There might be routing issues. Beware of the order in /etc/network/interfaces.