O.S.: Ubuntu Server 12.04 LTS
Module: Networking - Interfaces
I make use of KVM Hosts, and to manage VLANs we setup linux networking as follows:
physical interfaces in manual -> Bonding in static IP (untagged vlan) -> VLAN in manual (raw device is bond) -> Bridge in static or manual (bridge member is VLAN).
By doing so, I am able to assign bridges to virtual machine guests, and avoid VLAN configurations within the guest. This works perfectly when editing the /etc/network/interfaces file in Ubuntu, but I am unable to achieve this setup from Webmin. In webmin, it seems I can only select a NIC (eth0, eth1, etc) as bridge member. No bonded interfaces and no vlans.
Attaching a sample configuration file, hope this helps to better understand what I am trying to explain.
NOTE1. In the attached file, I used the VLAN100 format when creating interfaces (and declaring the raw device), per Ubuntu networking documentation. I tried with the bond1.100 format as well, but I was still unable to select it as Bridge interface from Webmin.
NOTE2. Bridges in this sample config have IP addresses. Those are not necessary. I added for a short while just to help troubleshoot networking.