Static IPv4/IPv6 Addresses - Debian 11

 Here’s how to set both static IPv4 and IPv6 addressing on Debian 11. The new portions are outlined in italics.

First, edit /etc/network/interfaces

auto lo  
auto ens192  
iface lo inet loopback  
# The primary network interface  
allow-hotplug ens192  
iface ens192 inet static  
    address _**{{ ipv4.address }}**_  
    gateway _**{{ ipv4.gateway }}**_  
iface ens192 inet6 static  
    address _**{{ ipv6.address }}**_  
    gateway _**{{ ipv6.gateway }}**_  

Then, restart your networking stack:

systemctl restart networking