--- title: "Update Subnet Properties" description: "Learn how to update the properties of an existing subnet. This can be needed if you want to comply with the prerequisites to be able to use the Public Cloud Gat" url: https://docs.us.ovhcloud.com/en/public-cloud/network-services/update-subnet-properties lang: en --- > For AI agents: the complete documentation index is available at https://docs.us.ovhcloud.com/en/llms.txt, the full documentation bundle is available at https://docs.us.ovhcloud.com/en/llms-full.txt. # Update Subnet Properties **Learn how to update the properties of an existing subnet.** This can be needed if you want to comply with the prerequisites to be able to use the Public Cloud Gateway: have a gateway IP defined in your subnet. For this example, we will use a private network and a subnet with the following properties: - CIDR 10.4.0.0/16 - DHCP enabled with allocation pool on the global range - No gateway IP We will see how to update it to have a Gateway IP set to `10.4.0.1` and remove that IP from the allocation pool.   ## Requirements - created a private network and a subnet as explained in [this guide](https://docs.us.ovhcloud.com/en/public-cloud/network-services/configure-vrack.md).   ## Instructions ### Using the OVHcloud Control Panel It is currently not possible to update a subnet through this interface but you can use our Horizon interface instead (see the instructions below).   ### Using Horizon Connect to Horizon and choose the region where the subnet is defined as explained in [this guide](https://docs.us.ovhcloud.com/en/public-cloud/cross-functional/introducing-horizon.md). Click on `Project > Network > Networks`. The page will display the list of networks available that contain an OVHcloud-managed network for public connectivity (`Ext-Net`) as well as your network. In that list, click on your network name ("Private\_Network\_VIN" in this example). The network detail page is then displayed. Click the `Subnets` tab to see the subnets from the private network. Click on `Edit Subnet`. For this guide, our target is to add a gateway IP: - Uncheck the `Disable Gateway` box. The field `Gateway IP` will appear. Fill it in with an IP within your CIDR (usually the first IP of the range is used). In our case, `10.4.0.1`. - Click on `Subnet Details`. Update the `Allocation Pools` to remove the Gateway IP that you entered in the previous step. In our case, we need to update from `10.4.0.1,10.4.255.254` to `10.4.0.2,10.4.255.254` Click on `Save` and your subnet is updated with a Gateway IP!   ### Using the OpenStack Command Line Interface You need to have your [CLI environment set up](https://docs.us.ovhcloud.com/en/public-cloud/cross-functional/compute-prepare-openstack-api-environment.md) and your [variables defined](https://docs.us.ovhcloud.com/en/public-cloud/cross-functional/compute-set-openstack-environment-variables.md). Run the following command (replace `Private_Network_VIN` with the name of your private network): ```bash ❯ openstack network show Private_Network_VIN ``` #### Example result: ```bash +---------------------------+--------------------------------------+ | Field | Value | +---------------------------+--------------------------------------+ | admin_state_up | UP | | availability_zone_hints | | | availability_zones | nova | | created_at | 2024-09-13T20:04:09Z | | description | | | dns_domain | None | | id | 0ff9XXXX-XXXX-XXXX-XXXX-XXXXXXXXX8a | | ipv4_address_scope | None | | ipv6_address_scope | None | | is_default | None | | is_vlan_transparent | None | | l2_adjacency | True | | mtu | 1500 | | name | Private_Network_VIN | | port_security_enabled | True | | project_id | REDACTED | | provider:network_type | vrack | | provider:physical_network | None | | provider:segmentation_id | 4 | | qos_policy_id | None | | revision_number | 5 | | router:external | Internal | | segments | None | | shared | False | | status | ACTIVE | | subnets | 50a7b953-b6a8-4097-92e4-6b71f0eada84 | | tags | | | tenant_id | REDACTED | | updated_at | 2024-09-13T20:04:15Z | +---------------------------+--------------------------------------+ ``` In this output, the `subnets` line provides the UID of your subnet. You can check your subnet details by running the following command (update the UID according to your value): ```bash ❯ openstack subnet show 50a7b953-b6a8-4097-92e4-6b71f0eada84 ``` #### Example result: ```bash +----------------------+--------------------------------------+ | Field | Value | +----------------------+--------------------------------------+ | allocation_pools | 10.4.0.1-10.4.255.254 | | cidr | 10.4.0.0/16 | | created_at | 2024-09-13T20:04:13Z | | description | | | dns_nameservers | 213.186.33.99 | | dns_publish_fixed_ip | None | | enable_dhcp | True | | gateway_ip |                                | | host_routes | | | id | 50a7b953-b6a8-4097-92e4-6b71f0eada84 | | ip_version | 4 | | ipv6_address_mode | None | | ipv6_ra_mode | None | | name | | | network_id | 0ff9XXXX-XXXX-XXXX-XXXX-XXXXXXXXX8a | | project_id | REDACTED | | revision_number | 0 | | segment_id | None | | service_types | | | subnetpool_id | None | | tags | | | updated_at | 2024-09-13T20:04:15Z | +----------------------+--------------------------------------+ ``` Now let's update the `gateway_ip` and the `allocation_pool`: ```bash ❯ openstack subnet set --gateway 10.4.0.1 --no-allocation-pool --allocation-pool start=10.4.0.2,end=10.4.255.254 50a7b953-b6a8-4097-92e4-6b71f0eada84 ``` You can check that the subnet has been updated: ```bash ❯ openstack subnet show 50a7b953-b6a8-4097-92e4-6b71f0eada84 ``` #### Example result: ```bash +----------------------+--------------------------------------+ | Field | Value | +----------------------+--------------------------------------+ | allocation_pools | 10.4.0.2-10.4.255.254 | | cidr | 10.4.0.0/16 | | created_at | 2024-01-19T10:44:33Z | | description | | | dns_nameservers | 213.186.33.99 | | dns_publish_fixed_ip | None | | enable_dhcp | True | | gateway_ip | 10.4.0.1 | | host_routes | | | id | 50a7b953-b6a8-4097-92e4-6b71f0eada84 | | ip_version | 4 | | ipv6_address_mode | None | | ipv6_ra_mode | None | | name | | | network_id | 0ff9XXXX-XXXX-XXXX-XXXX-XXXXXXXXX8a | | project_id | REDACTED | | revision_number | 1 | | segment_id | None | | service_types | | | subnetpool_id | None | | tags | | | updated_at | 2024-09-13T20:05:15Z | +----------------------+--------------------------------------+ ```   ## Go further Browse all the [Networking guides](https://docs.us.ovhcloud.com/en/public-cloud/network-services/landing-page-network-services.md). Browse the rest of the [OVHcloud US documentation](https://docs.us.ovhcloud.com/en/index.md) for guides on our other products and services. Learn more about [Public Cloud Network](https://us.ovhcloud.com/public-cloud/network/) on the OVHcloud US website. If you need training or technical assistance to implement our solutions, contact your sales representative or click on [this link](https://us.ovhcloud.com/professional-services/) to get a quote and ask our Professional Services experts for a custom analysis of your project.