Basic L3 operations

Creates external networks.

# neutron net-create public --router:external=True
$ neutron subnet-create public 172.16.1.0/24

Lists external networks.

$ neutron net-list -- --router:external=True

Creates an internal-only router that connects to multiple L2 networks privately.

$ neutron net-create net1
$ neutron subnet-create net1 10.0.0.0/24
$ neutron net-create net2
$ neutron subnet-create net2 10.0.1.0/24
$ neutron router-create router1
$ neutron router-interface-add router1 <subnet1-uuid>
$ neutron router-interface-add router1 <subnet2-uuid>

Connects a router to an external network, which enables that router to act as a NAT gateway for external connectivity.

$ neutron router-gateway-set router1 <ext-net-id>

The router obtains an interface with the gateway_ip address of the subnet, and this interface is attached to a port on the L2 Networking network associated with the subnet. The router also gets a gateway interface to the specified external network. This provides SNAT connectivity to the external network as well as support for floating IPs allocated on that external networks. Commonly an external network maps to a network in the provider

Lists routers.

$ neutron router-list

Shows information for a specified router.

$ neutron router-show <router_id>

Shows all internal interfaces for a router.

Identifies the port-id that represents the VM NIC to which the floating IP should map.

$ neutron port-list -c id -c fixed_ips -- --device_id=<instance_id>

This port must be on an Networking subnet that is attached to a router uplinked to the external network used to create the floating IP. Conceptually, this is because the router must be able to perform the Destination NAT (DNAT) rewriting of packets from the Floating IP address (chosen from a subnet on the external network) to the internal Fixed IP (chosen from a private subnet that is behind the router).

Creates a floating IP address and associates it with a port.

$ neutron floatingip-create <ext-net-id>
$ neutron floatingip-associate <floatingip-id> <internal VM port-id>

Creates a floating IP address and associates it with a port, in a single step.

$ neutron floatingip-create --port_id <internal VM port-id> <ext-net-id>

Lists floating IPs.

$ neutron floatingip-list

Finds floating IP for a specified VM port.

$ neutron floatingip-list -- --port_id=ZZZ

Disassociates a floating IP address.

$ neutron floatingip-disassociate <floatingip-id>

Deletes the floating IP address.

$ neutron floatingip-delete <floatingip-id>

Clears the gateway.

$ neutron router-gateway-clear router1

Removes the interfaces from the router.

$ neutron router-interface-delete router1 <subnet-id>

Deletes the router.

$ neutron router-delete router1