Why does this firewall rule block my internet?

I have been adding some bogon ip address in my firewall (I have been using this one as a starting point) and one in particular blocks internet traffic for me and I’m not sure why. I use the address 192.168.0.0/16 in the following lines;

add chain=forward src-address=192.168.0.0/16 action=drop
add chain=forward dst-address=192.168.0.0/16 action=drop

If I disable the first line it all works, but if I enable add chain=forward src-address=192.168.0.0/16 action=drop I can no longer access the internet.

Can anyone help me with this one?

Al of these and related

add chain=forward src-address=0.0.0.0/8 action=drop
add chain=forward dst-address=0.0.0.0/8 action=drop
add chain=forward src-address=127.0.0.0/8 action=drop
add chain=forward dst-address=127.0.0.0/8 action=drop
add chain=forward src-address=224.0.0.0/3 action=drop
add chain=forward dst-address=224.0.0.0/3 action=drop

is replace by this single line:

/ip settings
set rp-filter=strict

which means “drop any packet if it’s not logical to receive it on that interface”
https://wiki.mikrotik.com/wiki/Manual:IP/Settings

Great, thanks a million sebastia. That keeps my firewall rules much simpler as I had quite a few IP address in my bogon list :slight_smile:

but if I enable add chain=forward src-address=192.168.0.0/16 action=drop I can no longer access the internet.

That means your LAN is using that IP range.
I use a similar rule to block individual PCs when I first install new software to see if they try to ‘phone home’ after install.