By default all incoming traffic to most not just Meraki firewalls is blocked by default. I have yet to see any vendor allow any WAN > LAN traffic by default.
If you want to block port 500 outbound then simply create a rule doing so Security & SD-WAN > Configure > Firewall
![Screen Shot 2022-01-21 at 7.50.56 AM.png Screen Shot 2022-01-21 at 7.50.56 AM.png](https://community.meraki.com/t5/image/serverpage/image-id/21562iCE263487AB3FA5CA/image-size/large?v=v2&px=999)
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