Just another one note to remember how to…
In my case a new external network it is private subnet with NAT in public addresses.
1) Let’s make a backup of neutron config files.
2) Add a new vlan nterface for our private subnet. No ip address set.
3) Edit neutron server configuration:
In /etc/neutron/plugins/ml2/ml2_conf.ini add a new external network info.
network_vlan_ranges = physnet1:1:4094,extnet1,extnet2,extnet3,extnet4
bridge_mappings = extnet1:br-ex,extnet2:br-ex-2,extnet3:br-ex-3,extnet4:br-ex-4
Here in network_vlan_ranges I added extnet3 и extnet4 and appropriate mapping in bridge_mappings – extnet3:br-ex-3,extnet4:br-ex-4.
extnet4 added for future use. When we face a lack of any free IPs in extnet3 we can add new external network without neutron-server service restart.