:_mod-docs-content-type: PROCEDURE
[id="retrieving-the-network-configuration_{context}"]

= Retrieving the network configuration from your existing deployment

[role="_abstract"]
You must determine which isolated networks are defined in your existing
deployment. After you retrieve your network configuration, you have the following information:

* A list of isolated networks that are used in the existing deployment.
* For each of the isolated networks, the VLAN tag and IP ranges used for
  dynamic address allocation.
* A list of existing IP address allocations that are used in the environment.
  When reusing the existing subnet ranges to host the new control plane
  services, these addresses are excluded from the corresponding allocation
  pools.

ifeval::["{build_variant}" == "ospdo"]
For more information about director Operator network configurations, see link:https://docs.redhat.com/en/documentation/red_hat_openstack_platform/17.1/html-single/deploying_an_overcloud_in_a_red_hat_openshift_container_platform_cluster_with_director_operator/index#assembly_creating-networks-with-director-operator[Creating networks with director Operator] in _Deploying an overcloud in a Red Hat OpenShift Container Platform cluster with director Operator_.
endif::[]

.Procedure

. Find the network configuration in the `network_data.yaml` file. For example:
+
----
- name: InternalApi
  mtu: 1500
  vip: true
  vlan: 20
  name_lower: internal_api
  dns_domain: internal.mydomain.tld.
  service_net_map_replace: internal
  subnets:
    internal_api_subnet:
      ip_subnet: '172.17.0.0/24'
      allocation_pools: [{'start': '172.17.0.4', 'end': '172.17.0.250'}]
----

. Retrieve the VLAN tag that is used in the `vlan` key and the IP range in the
  `ip_subnet` key for each isolated network from the `network_data.yaml` file.
  When reusing subnet ranges from the existing deployment for the new control
  plane services, the ranges are split into separate pools for control
  plane services and load-balancer IP addresses.

. Use the `tripleo-ansible-inventory.yaml` file to determine the list of IP addresses that are already consumed in the adopted environment. For each listed host in the file, make a note of the IP and VIP addresses that are consumed by the node. For example:
+
----
Standalone:
  hosts:
    standalone:
      ...
      internal_api_ip: 172.17.0.100
    ...
  ...
standalone:
  children:
    Standalone: {}
  vars:
    ...
    internal_api_vip: 172.17.0.2
    ...
----
+
[NOTE]
In this example, the `172.17.0.2` and `172.17.0.100` values are
consumed and are not available for the new control plane services until the adoption is complete.

. Repeat this procedure for each isolated network and each host in the
configuration.