Difference between PPPOE and Ether1-Gateway in Firewall settings

RouterOS Beginner Basics
1

Hello there,

First post here.

I used to use a PPPOE provider and had several firewall/NAT rules setup. At the time, the rules used PPPOE as the “income” port", because Ether1-gateway didn’t seem to work.

Now I changed to a DHCP provider (no authentication) and it I had to change all that stuff.

Question: Why Ether1-gateway doesn’t work in PPPOE connections, if it used the Ether1 port? What’s the difference between PPPOE and Ether1-gateway?