Failover IPs, also known as floating IPs, are IPs that can be easily moved from device to device. This makes them optimal for networking VMs on a Dedicated Server, redundancy, IP aliasing, and many other use cases. In this guide, we will cover everything you need to know about how to use failover IPs with OVHcloud.
- General networking knowledge
- Basic Networking with a Failover IP
- Purchasing Failover IPs
- How to Use a Failover IP in the OVHcloud Manager
Basic Networking with a Failover IP
In this section, we will cover a couple of concepts about failover IPs that are important to understand from a networking perspective. While failover IPs can be purchased in blocks as small as /32 or as large as /24, the CIDR notation only indicates how many IPs you get. It does not denote a subnet. Every IP is routed through the host. This means that every IP a customer purchases can be used since no addresses need to be reserved for network, broadcast, or gateway.
Your gateway IP address will be determined independently of your failover IP block. At OVHcloud, we reserve the last available IP in each subnet (not including the broadcast address) for a gateway address. Additionally, all Dedicated Servers are given an IP on a /24 subnet. Meaning a Dedicated Server's gateway will always be the first three octets of its IP followed by .254. For example, if your Dedicated Server's IP was 203.0.113.34, its gateway would be 203.0.113.254. Since failover IPs are routed through the host, any VM or other service using the failover IP would also use this as the gateway address.
Purchasing Failover IPs
To begin, log in to the OVHcloud Manager. Then, click on the Order drop-down on the left-hand sidebar.
Next, select the Additional IP option.
From the "Order additional IPs" pop-up window, choose the environment to which you would like the IP address(es) to be attached.
Afterward, click the Next button.
In step two, select the number of IP addresses that you would like to purchase. The choices are: 1 (/32), 4 (/30), 8 (/29), 16 (/28), 32 (/27), 64 (/26), 128 (/25), and 256 (/24).
Note: By selecting one (/32) IP address, you have the option to purchase up to 16 individual IP addresses, but in one order. These IP addresses will be handled individually, which means they can be separately assigned to different servers/services.
Additionally, if you purchase a block of 4 IPs (/30) or greater, the IP addresses can still be moved, but as an entire block ONLY. Also, you are able to set the WHOIS information by using the "Click here to access the organization management" link.
Warning: If you elect to create an organization and assign it to a block of IP addresses, that information will be publicly accessible via a WHOIS search and CAN NOT be changed. If you are unsure how to proceed, we recommend selecting "ARIN_104".
After you have chosen your desired purchase, click the Next button. A confirmation notice appears:
Click the Confirm button to finalize your selection. You are taken to an order page to pay for the additional IP(s). After completing the order the additional IP address(es) will appear in the IP section of the OVHcloud Manager.
How to Use a Failover IP in the OVHcloud Manager
Once you have ordered the failover IP, it will show up in your account attached to the Dedicated Server to which you wish to attach it. It is easily identified by the
FO icon next to it. On the top-right menu, you can see three buttons allowing you to export your IPs to a CSV file, order additional IPs, or add an ARIN organization to your IP.
You can use the following menu to perform a few tasks on your failover IPs: adding a description, moving the failover IP to another service, parking it, or deleting the failover IP.
Warning: If you delete a Dedicated Server with attached failover IPs, the IPs will be moved to parked. Once IPs have been parked for 31 days, you will be charged $3 per month per IP to keep them on your account. Therefore, if you want to keep these IPs, attach them to another service to avoid this charge.
Having read this article, you should understand basic networking concepts for OVHcloud Failover IPs. You should also be able to order failover IPs and perform basic operations on them in the OVHcloud Manager.