Normaly I can put the WAN address of my modem in the Domain tab of the General Setup. , isn't.
No.
What you set here is the domain name you actually have on the WAN.
If you dont have a name just set it to something like "local" or "myLAN".
This name will be assigned as the domain to the clients that get their DHCP lease from pfSense.
Dont put numbers/IP's here.
Then I put in de Domain colom of the DNS Forwarder that WAN address. Will this then work or what shud I prepare.
Yes you put what you entered under domain in the general section here.
The IP field is the IP of your server.
The Host field can be left empty.
In my example: i have the domain "psymia.mine.nu".
If i enter "psymia.mine.nu" in firefox i access my server on 10.0.0.10.
I added a second entry with as host www:
If i enter "
www.psymia.mine.nu" in firefox i access my server on 10.0.0.10.