How to Assign Floating IPs in AlmaLinux, RockyLinux, CloudLinux, and CentOS

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A floating IP address helps handle requests to various services or applications on the same server. While a management IP address provides a fixed address for each server, floating IP addresses can be moved from one server to another as needed.

This guide will explain how to set up a floating IP address on your server by editing the network interfaces configuration file using “NetworkManager”. Before you get started, please ensure that you have root access to the server in order to carry out the steps outlined below.

If your server contains critical data, it is advised that you configure the floating IP manually as outlined in steps 4 and 5.

#Instructions to Assign IP Addresses to Your Servers

#Step 1: Access the Client Portal

Log in to your client portal.
Click on the "Network" button at the top of the menu bar.

#Step 2: Verify Your Floating IP Address

In the "Network" section, confirm that a floating IP address is linked to an instance.
Assign it using the "Attach +".

#Step 3: Identify Your Primary Network Interface

Use the “ip route” command to find the primary network interface. This will show the default route, which includes the primary network interface (e.g., eth0, bond0):
Command Line
```
ip route show default
```
You should see it in this line:
```
Output[root@new-kb-vps /]# ip route show default
default via 192.168.0.1 dev eth0 proto static metric 100
```

#Step 4: Configure the Floating IP Address Manually

OPTIONAL - Install the “nano” text editor if you prefer it over “vi”, which is pre-installed. You can do this by running:
Command Line
```
sudo dnf install nano
```
Change the directory to the network-scripts directory with the command:
Command Line
```
cd /etc/sysconfig/network-scripts/
```
Identify the appropriate configuration file for your network interface (e.g., ifcfg-eth0):
Command Line
```
ls
```
It should appear in this output line:
```
Output[root@new-kb-vps network-scripts]# ls
ifcfg-eth0 ifcfg-eth1 readme-ifcfg-rh.txt
```
Edit the identified network interface configuration file:
Command Line
```
sudo nano ifcfg-eth0
```
or use “vi”:
Command Line
```
sudo vi ifcfg-eth0
```

Under the current configuration, add your new floating IP address using the /32 subnet notation (e.g., 93.115.24.186/32). This should be added below your primary IP address.


Created by cloud-init automatically, do not edit.

AUTOCONNECT_PRIORITY=120
BOOTPROTO=none
DEFROUTE=yes
DEVICE=eth0
DNS1=8.8.8.8
DNS2=8.8.4.4
GATEWAY=192.168.0.1
HWADDR=54:52:00:10:d9:c7
IPADDR=5.199.168.117
NETMASK=255.255.255.255
ONBOOT=yes
TYPE=Ethernet
USERCTL=no

Floating IP configuration

IPADDR1=93.115.24.186
NETMASK1=255.255.255.255

Save the changes:
- In “nano” : Press Ctrl + X, Y, and Enter to save.
- In “vi” : Press Esc, type :wq, and press Enter to save and exit.
Restart the networking service to apply the changes with command:
Command Line
```
sudo systemctl restart NetworkManager 
```

#Step 5: Verify Configuration Persistence

Verify your IP addresses. Run the following script to do so:

nmcli device show eth0

You should see your primary and floating IP address above IP4.GATEWAY:

Output[root@new-kb-vps network-scripts]# nmcli device show eth0
GENERAL.DEVICE:                         eth0
GENERAL.TYPE:                           ethernet
GENERAL.HWADDR:                         54:52:00:10:D9:C7
GENERAL.MTU:                            1500
GENERAL.STATE:                          100 (connected)
GENERAL.CONNECTION:                     System eth0
GENERAL.CON-PATH:                       /org/freedesktop/NetworkManager/ActiveConnection/2
WIRED-PROPERTIES.CARRIER:               on
IP4.ADDRESS[1]:                         93.115.24.186/32
IP4.ADDRESS[2]:                         5.199.168.117/32
IP4.GATEWAY:                            192.168.0.1
IP4.ROUTE[1]:                           dst = 0.0.0.0/0, nh = 192.168.0.1, mt = 100
IP4.ROUTE[2]:                           dst = 192.168.0.1/32, nh = 0.0.0.0, mt = 100
IP4.DNS[1]:                             8.8.8.8
IP4.DNS[2]:                             8.8.4.4
IP6.ADDRESS[1]:                         fe80::5652:ff:fe10:d9c7/64
IP6.GATEWAY:                            --
IP6.ROUTE[1]:                           dst = fe80::/64, nh = ::, mt = 256

Test connectivity by running this command, and replacing the IP address, (5 93.115.24.186) with your own:
Command Line
```
ping -c 5 93.115.24.186 
```
Check that your IP address responds.

Your Floating IP is now successfully set up and will persist through any reboots.

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