RFC1918 Alias

Next, I create an alias for RFC1918.
RFC1918 normally stands for all private IP addresses in your local network.

In my setup, this alias is used for rules that allow internet access for a specific VLAN, except for anything inside RFC1918. This makes it much easier to create internet access rules for the VLANs.

• Go to Firewall > Aliases
• Hit the Plus-Symbol
• Enter the name RFC1918
• Choose type as networks(s)
• Selected content __wan_network__ (In future all those beginning with __)

Caution

Make sure to update this alias every time you add a new network/interface to your OPNSense otherwise VLAN’s could access devices on the connected network.