openstack-manuals/doc/install-guide/source/launch-instance-networks-selfservice.rst

Self-service network

If you chose networking option 2, you can also create a self-service (private) network that connects to the physical network infrastructure via NAT. This network includes a DHCP server that provides IP addresses to instances. An instance on this network can automatically access external networks such as the Internet. However, access to an instance on this network from external networks such as the Internet requires a floating IP address.

The demo or other unprivileged user can create this network because it provides connectivity to instances within the demo project only.

Warning

You must create the provider network <launch-instance-networks-provider> before the self-service network.

Note

The following instructions and diagrams use example IP address ranges. You must adjust them for your particular environment.

Networking Option 2: Self-service networks - Overview

Networking Option 2: Self-service networks - Connectivity

Create the self-service network

1. On the controller node, source the demo credentials to gain access to user-only CLI commands:

   $ . demo-openrc

2. Create the network:

   $ neutron net-create selfservice
   
   Created a new network:
   +-----------------------+--------------------------------------+
   | Field                 | Value                                |
   +-----------------------+--------------------------------------+
   | admin_state_up        | True                                 |
   | id                    | 7c6f9b37-76b4-463e-98d8-27e5686ed083 |
   | mtu                   | 0                                    |
   | name                  | selfservice                          |
   | port_security_enabled | True                                 |
   | router:external       | False                                |
   | shared                | False                                |
   | status                | ACTIVE                               |
   | subnets               |                                      |
   | tenant_id             | f5b2ccaa75ac413591f12fcaa096aa5c     |
   +-----------------------+--------------------------------------+

   Non-privileged users typically cannot supply additional parameters to this command. The service automatically chooses parameters using information from the following files:

   ml2_conf.ini:

   [ml2]
   tenant_network_types = vxlan
   
   [ml2_type_vxlan]
   vni_ranges = 1:1000

3. Create a subnet on the network:

   $ neutron subnet-create --name selfservice \
     --dns-nameserver DNS_RESOLVER --gateway SELFSERVICE_NETWORK_GATEWAY \
     selfservice SELFSERVICE_NETWORK_CIDR

   Replace DNS_RESOLVER with the IP address of a DNS resolver. In most cases, you can use one from the /etc/resolv.conf file on the host.

   Replace SELFSERVICE_NETWORK_GATEWAY with the gateway you want to use on the self-service network, typically the ".1" IP address.

   Replace SELFSERVICE_NETWORK_CIDR with the subnet you want to use on the self-service network. You can use any arbitrary value, although we recommend a network from RFC 1918.

   Example

   The self-service network uses 172.16.1.0/24 with a gateway on 172.16.1.1. A DHCP server assigns each instance an IP address from 172.16.1.2 to 172.16.1.254. All instances use 8.8.4.4 as a DNS resolver.

   $ neutron subnet-create --name selfservice \
     --dns-nameserver 8.8.4.4 --gateway 172.16.1.1 \
     selfservice 172.16.1.0/24
   
   Created a new subnet:
   +-------------------+------------------------------------------------+
   | Field             | Value                                          |
   +-------------------+------------------------------------------------+
   | allocation_pools  | {"start": "172.16.1.2", "end": "172.16.1.254"} |
   | cidr              | 172.16.1.0/24                                  |
   | dns_nameservers   | 8.8.4.4                                        |
   | enable_dhcp       | True                                           |
   | gateway_ip        | 172.16.1.1                                     |
   | host_routes       |                                                |
   | id                | 3482f524-8bff-4871-80d4-5774c2730728           |
   | ip_version        | 4                                              |
   | ipv6_address_mode |                                                |
   | ipv6_ra_mode      |                                                |
   | name              | selfservice                                    |
   | network_id        | 7c6f9b37-76b4-463e-98d8-27e5686ed083           |
   | subnetpool_id     |                                                |
   | tenant_id         | f5b2ccaa75ac413591f12fcaa096aa5c               |
   +-------------------+------------------------------------------------+

Create a router

Self-service networks connect to provider networks using a virtual router that typically performs bidirectional NAT. Each router contains an interface on at least one self-service network and a gateway on a provider network.

The provider network must include the router:external option to enable self-service routers to use it for connectivity to external networks such as the Internet. The admin or other privileged user must include this option during network creation or add it later. In this case, we can add it to the existing provider provider network.

1. On the controller node, source the admin credentials to gain access to admin-only CLI commands:

   $ . admin-openrc

2. Add the router: external option to the provider network:

   $ neutron net-update provider --router:external
   
   Updated network: provider

3. Source the demo credentials to gain access to user-only CLI commands:

   $ . demo-openrc

4. Create the router:

   $ neutron router-create router
   
   Created a new router:
   +-----------------------+--------------------------------------+
   | Field                 | Value                                |
   +-----------------------+--------------------------------------+
   | admin_state_up        | True                                 |
   | external_gateway_info |                                      |
   | id                    | 89dd2083-a160-4d75-ab3a-14239f01ea0b |
   | name                  | router                               |
   | routes                |                                      |
   | status                | ACTIVE                               |
   | tenant_id             | f5b2ccaa75ac413591f12fcaa096aa5c     |
   +-----------------------+--------------------------------------+

5. Add the self-service network subnet as an interface on the router:

   $ neutron router-interface-add router selfservice
   
   Added interface bff6605d-824c-41f9-b744-21d128fc86e1 to router router.

6. Set a gateway on the provider network on the router:

   $ neutron router-gateway-set router provider
   
   Set gateway for router router

Verify operation

We recommend that you verify operation and fix any issues before proceeding. The following steps use the IP address ranges from the network and subnet creation examples.

1. On the controller node, source the admin credentials to gain access to admin-only CLI commands:

   $ . admin-openrc

2. List network namespaces. You should see one qrouter namespace and two qdhcp namespaces.

   $ ip netns
   
   qrouter-89dd2083-a160-4d75-ab3a-14239f01ea0b
   qdhcp-7c6f9b37-76b4-463e-98d8-27e5686ed083
   qdhcp-0e62efcd-8cee-46c7-b163-d8df05c3c5ad

3. List ports on the router to determine the gateway IP address on the provider network:

   $ neutron router-port-list router
   
   +--------------------------------------+------+-------------------+------------------------------------------+
   | id                                   | name | mac_address       | fixed_ips                                |
   +--------------------------------------+------+-------------------+------------------------------------------+
   | bff6605d-824c-41f9-b744-21d128fc86e1 |      | fa:16:3e:2f:34:9b | {"subnet_id":                            |
   |                                      |      |                   | "3482f524-8bff-4871-80d4-5774c2730728",  |
   |                                      |      |                   | "ip_address": "172.16.1.1"}              |
   | d6fe98db-ae01-42b0-a860-37b1661f5950 |      | fa:16:3e:e8:c1:41 | {"subnet_id":                            |
   |                                      |      |                   | "5cc70da8-4ee7-4565-be53-b9c011fca011",  |
   |                                      |      |                   | "ip_address": "203.0.113.102"}           |
   +--------------------------------------+------+-------------------+------------------------------------------+

4. Ping this IP address from the controller node or any host on the physical provider network:

   $ ping -c 4 203.0.113.102
   
   PING 203.0.113.102 (203.0.113.102) 56(84) bytes of data.
   64 bytes from 203.0.113.102: icmp_req=1 ttl=64 time=0.619 ms
   64 bytes from 203.0.113.102: icmp_req=2 ttl=64 time=0.189 ms
   64 bytes from 203.0.113.102: icmp_req=3 ttl=64 time=0.165 ms
   64 bytes from 203.0.113.102: icmp_req=4 ttl=64 time=0.216 ms
   
   --- 203.0.113.102 ping statistics ---
   rtt min/avg/max/mdev = 0.165/0.297/0.619/0.187 ms

Return to Launch an instance - Create virtual networks <launch-instance-networks>.