Before launching an instance, you must create the necessary virtual network infrastructure. For networking option 1, an instance uses a provider (external) network that connects to the physical network infrastructure via layer-2 (bridging/switching). This network includes a DHCP server that provides IP addresses to instances.
The admin or other privileged user must create this network because it
connects directly to the physical network infrastructure.
Note
The following instructions and diagrams use example IP address ranges. You must adjust them for your particular environment.
Networking Option 1: Provider networks - Overview
Networking Option 1: Provider networks - Connectivity
On the controller node, source the admin credentials to gain access to
admin-only CLI commands:
$ . admin-openrc
Create the network:
$ openstack network create --share --external \
--provider-physical-network provider \
--provider-network-type flat provider
Created a new network:
+---------------------------+--------------------------------------+
| Field | Value |
+---------------------------+--------------------------------------+
| admin_state_up | UP |
| availability_zone_hints | |
| availability_zones | |
| created_at | 2016-11-02T20:36:18Z |
| description | |
| headers | |
| id | 9793a02d-4f05-40d2-a280-407c48db0161 |
| ipv4_address_scope | None |
| ipv6_address_scope | None |
| mtu | 1500 |
| name | provider |
| port_security_enabled | True |
| project_id | 7e188c33604d4b02ae0a99b5da68cae0 |
| provider:network_type | flat |
| provider:physical_network | provider |
| provider:segmentation_id | None |
| revision_number | 3 |
| router:external | External |
| shared | True |
| status | ACTIVE |
| subnets | |
| tags | [] |
| updated_at | 2016-11-02T20:36:18Z |
+---------------------------+--------------------------------------+
The --share option allows all projects to use the virtual network.
The --external option defines the virtual network to be external. If
you wish to create an internal network, you can use --internal instead.
Default value is internal.
The --provider-physical-network provider and
--provider-network-type flat options connect the flat virtual network
to the flat (native/untagged) physical network on the eth1 interface
on the host using information from the following files:
ml2_conf.ini:
[ml2_type_flat]
flat_networks = provider
linuxbridge_agent.ini:
[linux_bridge]
physical_interface_mappings = provider:eth1
Create a subnet on the network:
$ openstack subnet create --network provider \
--allocation-pool start=START_IP_ADDRESS,end=END_IP_ADDRESS \
--dns-nameserver DNS_RESOLVER --gateway PROVIDER_NETWORK_GATEWAY \
--subnet-range PROVIDER_NETWORK_CIDR provider
Replace PROVIDER_NETWORK_CIDR with the subnet on the provider
physical network in CIDR notation.
Replace START_IP_ADDRESS and END_IP_ADDRESS with the first and
last IP address of the range within the subnet that you want to allocate
for instances. This range must not include any existing active IP
addresses.
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 PROVIDER_NETWORK_GATEWAY with the gateway IP address on the
provider network, typically the ”.1” IP address.
Example
The provider network uses 203.0.113.0/24 with a gateway on 203.0.113.1. A DHCP server assigns each instance an IP address from 203.0.113.101 to 203.0.113.250. All instances use 8.8.4.4 as a DNS resolver.
$ openstack subnet create --network provider \
--allocation-pool start=203.0.113.101,end=203.0.113.250 \
--dns-nameserver 8.8.4.4 --gateway 203.0.113.1 \
--subnet-range 203.0.113.0/24 provider
Created a new subnet:
+-------------------+--------------------------------------+
| Field | Value |
+-------------------+--------------------------------------+
| allocation_pools | 203.0.113.101-203.0.113.250 |
| cidr | 203.0.113.0/24 |
| created_at | 2016-11-02T20:45:04Z |
| description | |
| dns_nameservers | 8.8.4.4 |
| enable_dhcp | True |
| gateway_ip | 203.0.113.1 |
| headers | |
| host_routes | |
| id | 2c65ef8c-a5f3-4f51-94c1-4df0daaaab5c |
| ip_version | 4 |
| ipv6_address_mode | None |
| ipv6_ra_mode | None |
| name | provider |
| network_id | 9793a02d-4f05-40d2-a280-407c48db0161 |
| project_id | 7e188c33604d4b02ae0a99b5da68cae0 |
| revision_number | 2 |
| service_types | [] |
| subnetpool_id | None |
| updated_at | 2016-11-02T20:45:04Z |
+-------------------+--------------------------------------+
Return to Launch an instance - Create virtual networks.
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