I came across this one today, and am putting it here to document it ofr my own benefit. I needed a physical machine with one NIC to be able to have two different IP addresses on two different VLAN’s.
On Windows I am not sure if that is possible by default.
So how would you do it on Redhat Linux (taken from Howto: Configure Linux Virtual Local Area Network (VLAN))
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
DEVICE=eth0 ONBOOT=yes BOOTPROTO=none 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