This post is an update to a previous post on using multiple interfaces(Ethernet cards) on the LAN, – utilizing RedHat’s popular virtualization tools – QEMU, KVM, libvirt, and virt-manager. In this article I will demonstrate with Fedora 21, but this roughly applies to CentOS 7 as well.
I’ve resisted upgrading to recent versions of Fedora/CentOS for a long time. The main reason is that I hate NetworkManager. It does to much automatically; I much preferred the old ‘network’ daemon that could easily be manually set. For instance if I create a Bridge(call it bridge1) interface assigned to my second Ethernet card(eth1) NetworkManager will automatically create a profile for each with automatic startup and DHCP enabled! I don’t need or want a DHCP lease on either side of a bridged interface! Among other issues are the creation of duplicate profiles when libvirt restarts. So NetworkManger reports ‘bridge1’ & ‘bridge1’ in the NM start menu applet.
Ideally libvirt and NetworkManager would work hand in hand because Redhat sponsors both projects…
In this article we will describe the steps to allow you to connect two seperate NIC’s to a switch; assigning one of the NIC’s specifically to guest VM’s.
Goals of this post:
- Set NetworkManager to ignore bridge and Ethernet device
- enable systemd version of rc.local boot script to create bridge at boot
- assign host to specific bridged Ethernet device