Today, I’m going to explain my config for KVM server to get network connectivity on guests machines using tagged vlans to get independent networks. As virtual platform I am using Proxmox ve. Proxmox is a great platform to administer KVM and OpenVZ machines, actually it is based on Debian Lenny, but very soon will be available the 2.0 version based on Debian Squeeze and with many great features.
I have connected my kvm server network interfaces to two different switches and the switch ports configured in trunk mode only accepting traffic for my tagged vlans. For vlan configuration I am using vlan package in debian, rather than specify them like eth0.X, I prefer to configure them using this tool.
To install vlan package simply run:
# apt-get install vlan
Above the two network interfaces I have configured a bond interface in active-backup mode. My /etc/network/interfaces file looks like this:
iface eth0 inet manual iface eth1 inet manual auto bond0 iface bond0 inet manual slaves eth0 eth1 bond_miimon 100 bond_mode active-backup auto vlan50 iface vlan50 inet manual vlan_raw_device bond0 auto vlan60 iface vlan60 inet manual vlan_raw_device bond0 auto vlan100 iface vlan100 inet manual vlan_raw_device bond0 auto vmbr0 iface vmbr0 inet static address 172.17.16.5 netmask 255.255.240.0 gateway 172.17.16.1 bridge_ports vlan100 bridge_stp off bridge_fd 0 auto vmbr50 iface vmbr50 inet static address 0.0.0.0 netmask 255.255.255.255 bridge_ports vlan50 bridge_stp off bridge_fd 0 auto vmbr60 iface vmbr60 inet static address 0.0.0.0 netmask 255.255.255.255 bridge_ports vlan60 bridge_stp off bridge_fd 0
I have three bridges configured, vmbr0 (with vlan 100), required to access proxmox web interface, and vmbr50 and vmbr60, each of them accessing to their vlans to provide access to guests. The bridge vmbr0 is the only bridge that has an IP address configured, because is the only interface I’m going to use to access to the kvm server.
Now, it is easy to provide network connectivity to the kvm guests machines, simply you have to link their network interfaces to the bridge you want depending on, to that vlan you want they get access.
For example, part of one of my kvm machine config file looks like this:
vlan60: virtio=DE:17:7C:C3:CE:B2 vlan50: virtio=B2:0A:19:3E:72:4D
This is automatically added using proxmox ve web interface.