...
Where to find reference on exact commands?
Differences between articles,
https://help.ubuntu.com/community/KVM/Networking - KVM specific, but also explains each item more,
auto lo iface lo inet loopback auto br0 iface br0 inet static address 192.168.0.10 network 192.168.0.0 netmask 255.255.255.0 broadcast 192.168.0.255 gateway 192.168.0.1 dns-nameservers 192.168.0.5 8.8.8.8 dns-search example.com bridge_ports eth0 bridge_stp off bridge_fd 0 bridge_maxwait 0
https://www.theurbanpenguin.com/ubuntu-server-creating-a-bridge-interface/ - mentions for KVM too,
auto br0 iface br0 inet static address 192.168.0.201 netmask 255.255.255.0 gateway 192.168.0.1 dns-nameservers 8.8.8.8 8.8.4.4 bridge_ports eth0 bridge_stp off
https://www.cyberciti.biz/faq/how-to-create-bridge-interface-ubuntu-linux/ - shows bridging with multiple cards... more complicated,
# br1 setup with static wan IPv4 with ISP router as gateway auto br1 iface br1 inet static address 208.43.222.51 network 255.255.255.248 netmask 255.255.255.0 broadcast 208.43.222.55 gateway 208.43.222.49 bridge_ports eth1 bridge_stp off bridge_fd 0 bridge_maxwait 0
auto br0 iface br0 inet static address 10.18.44.26 netmask 255.255.255.192 broadcast 10.18.44.63 dns-nameservers 10.0.80.11 10.0.80.12 # set static route for LAN post-up route add -net 10.0.0.0 netmask 255.0.0.0 gw 10.18.44.1 post-up route add -net 161.26.0.0 netmask 255.255.0.0 gw 10.18.44.1 bridge_ports eth0 bridge_stp off bridge_fd 0 bridge_maxwait 0