Firewall aliases
To introduce you to aliases, let's start with a little story.
Let's imagine that you oversee an OPNsense firewall in a network with thousands of hosts, dozens of network segments, and a lot of VPN tunnels. This scenario will probably (considering good security practices) demand a lot of different rules to control host traffic, right? So, this will easily produce more than a thousand rules (yes – this part is based on a real example!), and managing each host individually using the one rule per host approach can increase this number to tens of thousands of rules incredibly quickly, becoming a nightmare to anyone in charge of managing the firewall!
Now, imagine it being possible to group hosts by access profile, selecting both source and destination hosts and adding them to lists, and then creating firewall rules based only on these lists.
This will drastically reduce the number of rules, turning the nightmare into the firewall ruleset of dreams...