--- title: "Configuring an Additional IP block in a vRack" description: "This guide will show you how to configure a block of public IP addresses for use with the vRack." url: https://docs.ovhcloud.com/en/guides/bare-metal-cloud/dedicated-servers/configuring-an-ip-block-in-a-vrack lang: en lastUpdated: 2026-05-28 --- # Configuring an Additional IP block in a vRack ## Objective As well as private IP addressing, the [vRack](https://www.ovhcloud.com/en-gb/network/vrack/) also allows you to route public IP traffic through your server's vRack port using a public IP address block. **This guide will show you how to configure a block of public IP addresses for use with the vRack.** :::info vRack supports both IPv4 and IPv6 public routing with Additional IP address blocks. You can find the instructions on how to configure IPv6 blocks in this guide: "[Configuring an IPv6 block in a vRack](/en/guides/bare-metal-cloud/dedicated-servers/configure-ipv6-in-vrack.md)". ::: :::info This article is focusing on Additional IP configuration over a vRack network. If you look for guidance on Additional IP configuration together with primary IP (on public network interface), read the following articles: - IPv4: - [Configuring IP aliasing on dedicated servers](/en/guides/bare-metal-cloud/dedicated-servers/network-ipaliasing.md). - [Configuring IP aliasing on a VPS](/en/guides/bare-metal-cloud/virtual-private-servers/configuring-ip-aliasing.md). - IPv6: - [Configuring IPv6 on dedicated servers](/en/guides/bare-metal-cloud/dedicated-servers/network-ipv6.md). - [Configuring IPv6 on a VPS](/en/guides/bare-metal-cloud/virtual-private-servers/configure-ipv6.md). - [Configuring IPv6 on a Public Cloud instance](/en/guides/public-cloud/network-services/ipv6-configuration.md). ::: ## Requirements - A public block of IP addresses in your account, with a minimum of four addresses - Your chosen private IP address range - A [vRack compatible server](https://www.ovhcloud.com/en-gb/bare-metal/) - A [vRack](https://www.ovhcloud.com/en-gb/network/vrack/) service activated in your account *** ### OVHcloud Control Panel Access - **Direct link:** vRack - **Navigation path:** Network > vRack private network *** :::warning This feature might be unavailable or limited on servers of the [**Eco** product line](https://eco.ovhcloud.com/en-gb/about/). Please visit our [comparison page](https://eco.ovhcloud.com/en-gb/compare/) for more information. ::: ## Instructions :::info For example purposes we'll be using an IP block of 46.105.135.96/28 and eth1 for the secondary network interface, which is dedicated to the vRack. Also for example purposes, the network configuration file we refer to is located in `/etc/network/interfaces`. The equivalent file on your server may be located somewhere else, depending on your operating system. The file content may also be different. If you encounter any difficulties, please refer to the official documentation for your distribution. ::: ### Add the IP block to the vRack :::warning Once an IP block is added to the vRack, it is no longer attached to a physical server. This setup allows you to configure IPs of the same block on multiple servers, provided that these servers are all in the same vRack as the IP block. The IP block must have at least 2 usable IPs or more for this to be possible. ::: Select your vRack from the list to display the list of eligible services. Click the IP block you wish to add to the vRack and click on the `Add ` button. ![Add an IP block to the vRack](/images/bare-metal-cloud/dedicated-servers/configuring-an-ip-block-in-a-vrack/addIPblock.png) ### Managing public IP bandwidth on vRack By default, Additional IP blocks routed via a vRack benefit from a standard public bandwidth of 5 Gbps in Europe/Canada/US and 100 Mbps in APAC regions. For a detailed overview of availability, please refer to public routing options on our [vRack product page](https://www.ovhcloud.com/en-gb/network/vrack/). As infrastructure requirements scale, users may require broader bandwidth to support high-traffic public-oriented services, for which OVHcloud provides paid bandwidth options. It is important to note that bandwidth options are applied **per-vRack and per-region**. Since Additional IP addresses are tied to a region, any bandwidth modification will affect all IP addresses (both IPv4 and IPv6) routed to the specific vRack within that particular region. During the Additional IP ordering process #### Choosing public bandwidth during an Additional IP order The default public bandwidth can be changed when ordering a new Additional IP block with a vRack network as the backend. To order a new Additional IP block: - Open the Network section in the left-hand sidebar. - Select Public IP addresses. - Click on the Order IPs button, near the top of the page. - Select the IP version, then the vRack you want to attach your Additional IP to. - Select the region you want your Additional IP to be in. - Choose the public bandwidth you want to apply to your vRack for that specific region. - Fill in the other options as necessary, then proceed with your order. From the vRack management page #### Modifying vRack public bandwidth on management page For Additional IP blocks already attached to a vRack, bandwidth can be managed directly through the service configuration page. To access the management interface: - In the "Public IP & bandwidth" column, click the Manage button for the corresponding vRack. The management page is organized into two tabs: - **All attached services**: For the time being, it redirects to the classic vRack management page. Soon, it will list all the products (Servers, Cloud Projects, etc.) currently linked to the vRack, in a new way. - **Public IP routing**: Manages the public IP routing options of your vRack, including public bandwidth. To modify the public bandwidth: - Navigate to the Public IP routing tab. - The interface displays individual management windows for each region (e.g., `eu-west-par`) associated with the vRack, listing all IP addresses attached to that specific region. - Within the window for the relevant region, click the Modify bandwidth button. - Select the desired bandwidth option in the panel that appears on the right-hand side, then click Proceed to order to validate the order. - Once paid, the selected bandwidth should be available to your vRack in the chosen region after a few minutes. :::info Charges for the initial month are pro-rated based on the remaining days, with the full rate effective the next billing cycle. ::: The selected bandwidth upgrade will apply to all IP addresses in that region for the chosen vRack. ### Managing 3-AZ failover priorities Some OVHcloud regions span three Availability Zones (AZs) hosted in physically independent locations within the same region. When such a region is involved in your vRack public IP routing, it is identified in the OVHcloud Control Panel by a **3-AZ** badge displayed next to the region name in the `Public IP routing ` tab. :::info If a region transitioned to 3-AZ while you already had IPs routed via the vRack in that region, those IPs will remain in 1-AZ mode and will not automatically benefit from the 3-AZ routing configuration. To enable 3-AZ mode for IP blocks routed via the vRack in such regions, remove the IP block from the vRack, then re-add it. **IP blocks that are still routed in 1-AZ mode are identified by a grey `1-AZ` badge.** ::: #### Benefits - **Built-in resilience**: public IP traffic routed via the vRack remains available if a single Availability Zone becomes unavailable, as routing automatically fails over to the next AZ in the priority order. - **Predictable failover behaviour**: each 3-AZ region gives your vRack a Primary Availability Zone and two ordered failover positions, making the failover sequence deterministic. - **Workload alignment**: when other OVHcloud services are deployed in the same 3-AZ region, priorities can be aligned so that the vRack's active AZ matches the AZ hosting your services. This keeps your public traffic in the same AZ as your workload during normal operation. #### Mechanics and priority management When a vRack is first associated with a 3-AZ region, OVHcloud assigns a random priority order to its availability zones. The **Primary** , **Secondary** , and **Last resort** zones are displayed in order of priority in the corresponding region tile on the `Public IP routing ` tab, within the `3-AZ failover priorities` subsection, right above a `Configure ` button. You can override this random assignment at any time, for example to align failover priorities with the AZ layout of other components attached to your infrastructure. Modify the Availability Zone priorities To adjust the failover priorities of a 3-AZ region: - Open Network in the left-hand sidebar of your Control Panel. - Select vRack private network. - In the "Public IP & bandwidth" column, click the Manage button for the corresponding vRack. - Open the Public IP routing tab. - Locate the tile of the 3-AZ region you want to configure, then the `3-AZ failover priorities` subsection, and click Configure. - In the panel that opens, assign each Availability Zone to one of the three slots: **Primary Zone**, **Secondary Zone** and **Last resort Zone**. - Confirm your selection. :::info Priority changes apply to all Additional IP blocks routed to the corresponding 3-AZ region for the selected vRack, regardless of their IP version. ::: ### Configure a usable IP address For vRack purposes, the first, penultimate, and last addresses in any given IP block are always reserved for the network address, network gateway, and network broadcast respectively. This means that the first useable address is the second address in the block, as shown below: ```sh 46.105.135.96 Reserved: Network address 46.105.135.97 First usable IP 46.105.135.98 46.105.135.99 46.105.135.100 46.105.135.101 46.105.135.102 46.105.135.103 46.105.135.104 46.105.135.105 46.105.135.106 46.105.135.107 46.105.135.108 46.105.135.109 Last usable IP 46.105.135.110 Reserved: Network gateway 46.105.135.111 Reserved: Network broadcast ``` To configure the first usable IP address, we need to edit the network configuration file, as shown below. In this example, we need to use a subnet mask of **255.255.255.240**. :::info The subnet mask we've used in our example is appropriate for our IP block. Your subnet mask may differ depending on the size of your block. When you purchase your IP block, you'll receive an email that will tell you which subnet mask to use. ::: ### Download the `iproute2` package Before you begin, download and install **iproute2**, a package for manual IP routing configuration. This package may already be available on your server — if so, skip to the next step. Establish an SSH connection to your server and run the following command from the command line. This will download and install iproute2. ```sh # apt-get install iproute2 ``` Next, we need to create a new IP route for the vRack. We'll be adding a new traffic rule by amending the file, as shown below: ```sh /etc/iproute2/rt_tables # # reserved values # 255 local 254 main 253 default 0 unspec # # local # #1 inr.ruhep 1 vrack ``` ### Amend the network configuration file :::info For example purposes, the network configuration file we refer to is located in /etc/network/interfaces. The equivalent file on your server may be located somewhere else, depending on your operating system. ::: Finally, we need to amend the network configuration file to account for the new traffic rule and route the vRack traffic through the network gateway address of **46.105.135.110**. ```sh /etc/network/interfaces auto eth1 iface eth1 inet static address 46.105.135.97 netmask 255.255.255.240 broadcast 46.105.135.111 post-up ip route add 46.105.135.96/28 dev eth1 table vrack post-up ip route add default via 46.105.135.110 dev eth1 table vrack post-up ip rule add from 46.105.135.96/28 table vrack post-up ip rule add to 46.105.135.96/28 table vrack ``` **Fedora** ```sh sudo dnf install iproute ``` ### CentOS 6/7 #### Create the file for the secondary network interface First we can copy and use the configuration being used for the primary network interface and adjust it as per our needs: ```sh sudo cp /etc/sysconfig/network-scripts/ifcfg-eth0 /etc/sysconfig/network-scripts/ifcfg-eth1 ``` Then we access to the new file: ```sh sudo nano /etc/sysconfig/network-scripts/ifcfg-eth1 ``` And we define the IP settings: ```sh # Created by cloud-init on instance boot automatically, do not edit. # DEVICE=eth1 BOOTPROTO=static ONBOOT=yes USERCTL=no IPV6INIT=no PEERDNS=yes TYPE=Ethernet NETMASK=255.255.255.240 IPADDR=46.105.135.97 ARP=yes ``` ### Create a new IP routing table Next, we need to create a new IP route for the vRack. We'll be adding a new traffic rule by amending the file, as shown below: ```sh /etc/iproute2/rt_tables # # reserved values # 255 local 254 main 253 default 0 unspec # # local # #1 inr.ruhep 1 vrack ``` Next, create the file needed to apply the new rules: ```sh nano /etc/sysconfig/network-scripts/rule-eth1 ``` And paste the following content (please remember to replace our variables with your own values): ```sh from 46.105.135.96/28 table vrack to 46.105.135.96/28 table vrack ``` ### Amend the network configuration file Finally, we need to amend the network configuration file to account for the new traffic rule and route the vRack traffic through the network gateway address of **46.105.135.110**. We can achieve it by editing the following file in order to add persistent and static routes: ```sh nano /etc/sysconfig/network-scripts/route-eth1 ``` Paste the following content (please remember to replace our variables with your own values): ```sh 46.105.135.96/28 dev eth1 table vrack default via 46.105.135.110 dev eth1 table vrack ``` Now reboot your server to apply the changes or alternatively enable simply the new network interface: ```sh ip link set eth1 up ``` #### GNU/Linux configurations ****Debian 11**** **Configure the Additional IP** Using a text editor of your choice, open the network configuration file located in `/etc/network/interfaces.d` for editing. Here the file is called `50-cloud-init`. ```sh /etc/network/interfaces.d/50-cloud-init auto eth1 iface eth1 inet static address 46.105.135.97 netmask 255.255.255.240 broadcast 46.105.135.111 ``` **Create a new IP routing table** Next, we need to create a new IP route for the vRack. We'll be adding a new traffic rule by amending the file, as shown below: ```sh sudo nano /etc/iproute2/rt_tables # # reserved values # 255 local 254 main 253 default 0 unspec # # local # #1 inr.ruhep 1 vrack ``` **Amend the network configuration file** :::info For example purposes, the network configuration file we refer to is located in /etc/network/interfaces. The equivalent file on your server may be located somewhere else, depending on your operating system. ::: Finally, we need to amend the network configuration file to account for the new traffic rule and route the vRack traffic through the network gateway address of **46.105.135.110**. ```sh sudo nano /etc/network/interfaces.d/50-cloud-init auto eth1 iface eth1 inet static address 46.105.135.97 netmask 255.255.255.240 broadcast 46.105.135.111 post-up ip route add 46.105.135.96/28 dev eth1 table vrack post-up ip route add default via 46.105.135.110 dev eth1 table vrack post-up ip rule add from 46.105.135.96/28 table vrack post-up ip rule add to 46.105.135.96/28 table vrack ``` Now reboot your server to apply the changes or alternatively simply enable the new network interface: ```sh ip link set eth1 up ``` ****CentOS, AlmaLinux and Rocky Linux (8/9)**** **Create the file for the secondary network interface** First, copy the primary network interface configuration and adjust it as needed: ```sh sudo cp /etc/sysconfig/network-scripts/ifcfg-eth0 /etc/sysconfig/network-scripts/ifcfg-eth1 ``` Then, open the new file: ```sh sudo nano /etc/sysconfig/network-scripts/ifcfg-eth1 ``` - Define the IP settings: ```sh # Created by cloud-init on instance boot automatically, do not edit. # DEVICE=eth1 BOOTPROTO=static ONBOOT=yes USERCTL=no IPV6INIT=no PEERDNS=yes TYPE=Ethernet NETMASK=255.255.255.240 IPADDR=46.105.135.97 ARP=yes ``` **Create a new IP routing table** Next, we need to create a new IP route for the vRack. We'll be adding a new traffic rule by amending the file, as shown below: ```sh sudo nano /etc/iproute2/rt_tables # # reserved values # 255 local 254 main 253 default 0 unspec # # local # #1 inr.ruhep 1 vrack ``` Next, create the file needed to apply the new rules: ```sh nano /etc/sysconfig/network-scripts/rule-eth1 ``` And paste the following content (please remember to replace our variables with your own values): ```sh from 46.105.135.96/28 table vrack to 46.105.135.96/28 table vrack ``` **Amend the network configuration file** Finally, we need to amend the network configuration file to account for the new traffic rule and route the vRack traffic through the network gateway address of **46.105.135.110**. Edit the following file to add persistent and static routes: ```sh nano /etc/sysconfig/network-scripts/route-eth1 ``` Paste the following content (please remember to replace our variables with your own values): ```sh 46.105.135.96/28 dev eth1 table vrack default via 46.105.135.110 dev eth1 table vrack ``` Now reboot your server to apply the changes or alternatively simply enable the new network interface: ```sh ip link set eth1 up ``` ****Ubuntu & Debian 12+**** - Configure the Additional IP Using a text editor of your choice, open the network configuration file located in `/etc/netplan` for editing. Here the file is called `50-cloud-init.yaml`. ```sh sudo nano /etc/netplan/50-cloud-init.yaml ``` - Define the IP settings with the following variables: ```sh NETWORK_INTERFACE: dhcp4: false addresses: - ADDITIONAL_IP/PREFIX routes: - to: NETWORK_IP/PREFIX via: GATEWAY_IP ``` **Example** ```sh eno2: dhcp4: false addresses: - 46.105.135.97/28 routes: - to: 46.105.135.96/28 via: 46.105.135.110 ``` Apply the configuration with the following command: ```bash sudo netplan apply ``` ****Fedora, AlmaLinux and Rocky Linux (10)**** First, verify that your vRack interface is `connected` or `connecting` state. In our example, the interface is called `eno2`. ```sh nmcli device status DEVICE TYPE STATE CONNECTION eno1 ethernet connected cloud-init eno1 lo loopback connected (externally) lo eno2 ethernet connecting (getting IP configuration) vRack ``` Next, retrieve the name of the configuration file located in `/etc/NetworkManager/system-connections` for editing. Here the file is called `vRack.nmconnection`. ```sh [user@server ~]$ cd /etc/NetworkManager/system-connections cloud-init-eno1.nmconnection vRack.nmconnection ``` Using the `nmcli` handler, configure your Additional IP. Replace `vRack` and other parameters with your own values. - Add the IP ```sh sudo nmcli connection modify vRack IPv4.address 46.105.135.96/28 ``` - Add the Gateway ```sh sudo nmcli connection modify vRack IPv4.gateway 46.105.135.110 ``` - Change the configuration from **auto** to **manual**: ```sh sudo nmcli connection modify vRack IPv4.method manual ``` - Make the configuration persistent ```sh sudo nmcli con mod 'vRack' connection.autoconnect true ``` **Create a new IP routing table** Next, we need to create a new IP route for the vRack. We'll be adding a new traffic rule (`1 vrack`) by amending the file, as shown below: ```sh sudo nano /usr/share/iproute2/rt_tables # # reserved values # 255 local 254 main 253 default 0 unspec # # local # #1 inr.ruhep 1 vrack ``` - Add the route ```sh sudo ip route add / via dev ``` In our example ```sh sudo ip route add 46.105.135.96/28 via 46.105.135.110 dev eno2 ``` Restart your network with the following command: ```bash sudo systemctl restart NetworkManager ``` ### Windows Server #### Step 1: Check and configure the secondary network interface First, check the new network interface information: ![check the second network interface](/images/bare-metal-cloud/dedicated-servers/configuring-an-ip-block-in-a-vrack/win-ip-vrack-1.png) Then, check the properties: ![properties of the second network interface](/images/bare-metal-cloud/dedicated-servers/configuring-an-ip-block-in-a-vrack/win-ip-vrack-2.png) ![properties of the second network interface](/images/bare-metal-cloud/dedicated-servers/configuring-an-ip-block-in-a-vrack/win-ip-vrack-3.png) #### Step 2: IP Configuration Select the `Use the following IP address ` option: ![ip configuration](/images/bare-metal-cloud/dedicated-servers/configuring-an-ip-block-in-a-vrack/win-ip-vrack-4.png) Define the IP information: ![ip configuration](/images/bare-metal-cloud/dedicated-servers/configuring-an-ip-block-in-a-vrack/win-ip-vrack-5b.png) #### Step 3: Rebooting the network interface First, disable the interface. ![disabling network](/images/bare-metal-cloud/dedicated-servers/configuring-an-ip-block-in-a-vrack/win-ip-vrack-6.png) Then, enable the interface. ![enabling network](/images/bare-metal-cloud/dedicated-servers/configuring-an-ip-block-in-a-vrack/win-ip-vrack-7.png) ### Troubleshooting If you are unable to establish a connection from your VM or server to the private network, please send us a ticket from your Control Panel with the following: - IP source and IP destination - Ifconfig -a or ipconfig /all from both servers or VMs (setup network configuration interface) - Ping in both ways - Arp -a - Routing table Include the results above in your ticket. ## Go further [Configuring the vRack on your dedicated servers](/en/guides/bare-metal-cloud/dedicated-servers/vrack-configuring-on-dedicated-server.md) [Creating multiple vLANs in a vRack](/en/guides/bare-metal-cloud/dedicated-servers/creating-multiple-vlans-in-a-vrack.md) [Configuring the vRack between the Public Cloud and a Dedicated Server](/en/guides/bare-metal-cloud/dedicated-servers/configuring-the-vrack-between-the-public-cloud-and-a-dedicated-server.md) Join our [community of users](https://community.ovhcloud.com/).