# Network Config

There are several different qualities that networks in OpenStack might have that might not be able to be automatically inferred from the available metadata. To help users navigate more complex setups, os-client-config allows configuring a list of network metadata.

    clouds:
      amazing:
        networks:
        - name: blue
          routes_externally: true
        - name: purple
          routes_externally: true
          default_interface: true
        - name: green
          routes_externally: false
        - name: yellow
          routes_externally: false
          nat_destination: true
        - name: chartreuse
          routes_externally: false
          routes_ipv6_externally: true
        - name: aubergine
          routes_ipv4_externally: false
          routes_ipv6_externally: true

Every entry must have a name field, which can hold either the name or the id of the network.

routes_externally is a boolean field that labels the network as handling north/south traffic off of the cloud. In a public cloud this might be thought of as the “public” network, but in private clouds it’s possible it might be an RFC1918 address. In either case, it’s provides IPs to servers that things not on the cloud can use. This value defaults to false, which indicates only servers on the same network can talk to it.

routes_ipv4_externally and routes_ipv6_externally are boolean fields to help handle routes_externally in the case where a network has a split stack with different values for IPv4 and IPv6. Either entry, if not given, defaults to the value of routes_externally.

default_interface is a boolean field that indicates that the network is the one that programs should use. It defaults to false. An example of needing to use this value is a cloud with two private networks, and where a user is running ansible in one of the servers to talk to other servers on the private network. Because both networks are private, there would otherwise be no way to determine which one should be used for the traffic. There can only be one default_interface per cloud.

nat_destination is a boolean field that indicates which network floating ips should be attached to. It defaults to false. Normally this can be inferred by looking for a network that has subnets that have a gateway_ip. But it’s possible to have more than one network that satisfies that condition, so the user might want to tell programs which one to pick. There can be only one nat_destination per cloud.

nat_source is a boolean field that indicates which network floating ips should be requested from. It defaults to false. Normally this can be inferred by looking for a network that is attached to a router. But it’s possible to have more than one network that satisfies that condition, so the user might want to tell programs which one to pick. There can be only one nat_source per cloud.

this page last updated: 2026-01-16 23:06:19

Except where otherwise noted, this document is licensed under Creative Commons Attribution 3.0 License. See all OpenStack Legal Documents.