It's normal to see a reduction in the internet speed when using a PPPoE connection, as the connection requires some overhead for the authentication process.
However, a reduction of 60-70 MBps is quite significant and there could be a few reasons for this. Here are some things you can try to troubleshoot the issue:
- Check the PPPoE connection settings on your router to make sure they are correct.
- Check if there are any other devices connected to your network that may be using bandwidth and causing congestion.
- Try connecting to the internet using a wired connection instead of a wireless connection, as this can often provide a more stable and faster connection.
- Check if there are any issues with your internet service provider or with the cables or equipment used to connect to the internet.
- Check if the MTU value is set correctly. A value that is too low can cause problems with the PPPoE connection.
- Check if the firewall rules are configured correctly and not blocking any necessary traffic.
I hope this helps!