I need help designing networking for virtualized guests using KVM. My machine is running CentOS 7 and has 2 NICs. I'd like to achieve the following
- One physical interface (em1) shall be used for host access only. The host will have a pretty normal configuration with untagged traffic and a static IP address.
- The other physical interface (em2) receives tagged traffic for different VLANs.
- The virtual machines shall only see the traffic for their specific VLAN. Inter-Guest communication is not required to be done within the KVM.
- I would prefer the traffic on the virtual NIC to be untagged, to make sure that the guest doesn't change its internal NIC config to spoof other networks.
I am new to libvirt and also not used to Network Manager. I searched for documentation but found conflicting information, starting with the question whether it is possible to configure this bridging via network manager. I also read about the possibility to let the KVM do the switching.
I would be grateful for either direct configuration help or a pointer to an up-to-date documentation that does not use (on CentOS 7) deprecated tools or workarounds for problems removed in the meantime.
Thanks in advance.