I've been reading the RHEL documetation on KVM as well as networking, and I'm trying to wrap my head around br#, virbr#, and virbr#-nic devices. I've played around with virt-manager all afternoon, and based on this activity, I understand the following to be correct:
1) a br# device is a host-OS-level device used to bridge two network interfaces, virtual, logical, or physical.
2) a virb# device is created to be the router/gateway for a virtual network, so if I create the virtual network 10.0.1.0/24, then 10.0.1.1/24 is a virbr# device.
3) a virbr#-nic device is a virtual NIC used by a guest OS???
Is this understanding correct? Thanks for your time reading my question!
Yes..!!! you got it correctly.
1. #br is a bridge adapter which is giving direct access to external network to your guest os
2. whereas #virbr is working as a NAT adapter which is giving internal network so that guest vms can have ip address and they can have external access as well through this device.
3. and the last #virbr-nic, this is the NIC for guest vms.