1. add the below option in the file “/etc/default/grub and add ipv6.disable=1”

# cat /etc/default/grub
GRUB_TIMEOUT=5
GRUB_DEFAULT=saved
GRUB_DISABLE_SUBMENU=true
GRUB_TERMINAL_OUTPUT=”console”
GRUB_CMDLINE_LINUX=”ipv6.disable=1 crashkernel=auto rhgb quiet”
GRUB_DISABLE_RECOVERY=”true”

** add the option highlighted in bold.

2. After modifying the file, run the below command to generate new grub configuration

grub2-mkconfig -o /boot/grub2/grub.cfg

3. Reboot the server for the

/sbin/reboot

.