Woukd you like to completely replace 1 IP to another on the whole server? You may use ipswap.sh script for this. Step #4 from https://help.directadmin.com/item.php?id=250.
/usr/local/directadmin/scripts/ipswap.sh <oldip> <newip> [<file>]
cd /usr/local/directadmin/scripts
./ipswap.sh 1.2.3.4 4.3.2.1
Directadmin allows to change one IP to another at once globally for all accounts and sites:
Code:/usr/local/directadmin/scripts/ipswap.sh <oldip> <newip> [<file>]
Run the ipswap.sh script to replace the old server IP (1.2.3.4) with the new server IP (4.3.2.1)
Code:cd /usr/local/directadmin/scripts ./ipswap.sh 1.2.3.4 4.3.2.1
This script can be run on any ip, so if you want to change all ips with new ones, just run this script for each old ip with the new ip. Just ensure that you match the new server ip with the old one. As mentioned before, you must not add the new IP do DA through the IP Manager. The new server IP is to be added using the ipswap.sh script. It will remove the old IP as well automatically.
source link: https://help.directadmin.com/item.php?id=250