neutron-specs/misc/api/layer-3_networking.rst

Layer-3 networking (router)

The Layer-3 networking extension enables OpenStack Networking API users to route packets between subnets, forward packets from internal networks to external ones, and access instances from external networks through floating IPs.

The OpenStack Networking Layer-3 extension defines these resources:

• router. A logical entity that forwards packets across internal subnets and NATs them on external networks through an appropriate external gateway. A router has an interface for each subnet with which it is associated. By default, the IP address of such interface is the subnet's gateway IP. Also, whenever a router is associated with a subnet, a port for that router interface is added to the subnet's network.
• floating IP. Represents an external IP address that is mapped to an OpenStack Networking port and, optionally, a specific IP address on a private OpenStack Networking network. A floating IP enables access to an instance on a private network from an external network. Floating IPs can only be defined on networks where the router:external attribute (by the external network extension) is set to True.

Router attributes

Attribute	Type	Required	CRUD	Default value	Validation constraints	Notes
id	uuid-str	N/A	R	generated	N/A	Unique identifier for the router.
name	String	No	CRU	None	N/A	Human readable name for the router. Does not have to be unique.
admin_state_up	Bool	No	CRU	true	{truefalse}	Administrative state of the router.
status	String	N/A	R	N/A	N/A	Indicates whether or not a router is currently operational.
tenant_id	uuid-str	No	CR	Derived from Authentication token	N/A	Owner of the router. Only admin users can specify a tenant identifier other than its own.
external_gateway_info	dict	No	CRU	None	No constraint	Information on external gateway for the router.

Floating IP attributes

Attribute	Type	Required	CRUD	Default value	Validation constraints	Notes
id	uuid-str	N/A	R	generated	N/A	Unique identifier for the floating IP instance.
floating_network_id	uuid-str	Yes	CR	N/A	UUID Pattern	UUID of the external network where the floating IP is to be created.
port_id	uuid-str	Yes	CRU	N/A	UUID Pattern	UUID of the port on an internal OpenStack Networking network which should be associated to the floating IP.
fixed_ip_address	IP Address	No	CRU	None	IP address or null	Specific IP address on port_id which should be associated with the floating IP.
floating_ip_address	IP Address	N/A	R	Address of the floating IP on the external network.
tenant_id	uuid-str	No	CR	Derived from Authentication token	N/A	Owner of the floating IP. Only admin users can specify a tenant identifier other than its own.

..note: C means, use the attribute in create operations. R means this attribute is returned in response to show and list operations. U means you can update the value of this attribute. D means you can delete the value of this attribute.