Simple rule not working

[SamBox83]

Hi everyone,
I am new to opnsense and stuck on a seemingly simple problem: I can't get the internet working. At least not in the way I want it.

My internet is provided by a fritzbox router that connects to hn0 on my opnsense. I have multiple interfaces set up for the different separate networks I want to use, but I want to start learning by just using the LAN interface.
Now if I set up a rule with:
- Source: LAN
- Port: *
- Destination: *
- Port: *

then all works well, I am able to use the internet and ping the devices in the other networks.
(no rules have been set on anything other than the LAN interface. That also goes for the WAN interface as I am not sure what I would want there)

However, when I change it to:
- Source: LAN
- Port: *
- Destination: WAN net
- Port: *

then no connection is possible. To make any rule changes I always have to go and reset the state table, otherwise all connections stay open, even if I disable the rule (which should prevent any connection other than to the gui, right?)

I don't really know why I am not able to make such a simple thing work, maybe my install is bad somewhere?
Does anyone have an idea what could be the reason?

[tiermutter]

WAN_net means for your sense the network between Fritzbox and the sense.
With this rule, you only have access from LAN to this small network (WAN sense and LAN/DMZ Fritzbox).
For the issue with resetting states see this Thread: https://forum.opnsense.org/index.php?topic=30392.msg146651#msg146651

[SamBox83]

Ah, well that explains it.
But what would be the correct way of setting it up?
Allow all and then block all other networks?

[tiermutter]

Depends on how much you need to block... for a few networks I would allow any for LAN and create a block rule for each network that should not be reachable.