wan = DHCP(ISP network) + PPPoe(Internet)
How to block a packets from DHCP(ISP network) ?
Firewal|WAN operates only on pppoe connection
Use the "Floating Rules" tab and just create a rule to block udp packets on port 67 incoming from not your lan ~~network to any.
Do not specify the interface on the rule.
That should get you up and running.~~