Linux PPPoE/ADSL Clinet Support

The ncurses utility PPPoE/ADSL - PPP over ethernet driver. pppoeconf Configures PPP/ADSL connections.

pppoe clamp MSS at 1452 bytes  (If you still get problems described above try setting to 1412 in the dsl-provider file.)
Now, you can make a DSL connection with "pon dsl-provider" and terminate it with "poff".  
You can use the "plog" command to see the status or "ip addr show ppp0" for general interface info.

undo

Uninstall pppoeconf

To remove just pppoeconf package itself from Ubuntu 16.04 (Xenial Xerus) execute on terminal:

sudo apt-get remove pppoeconf

Uninstall pppoeconf and it's dependent packages

To remove the pppoeconf package and any other dependant package which are no longer needed from Ubuntu Xenial.

sudo apt-get autoremove pppoeconf

Purging pppoeconf

If you also want to delete configuration and/or data files of pppoeconf from Ubuntu Xenial then this will work:

sudo apt-get purge pppoeconf

To delete configuration and/or data files of pppoeconf and it's dependencies from Ubuntu Xenial then execute:

sudo apt-get autoremove --purge pppoeconf

In Linux Mint 19.2 the file /etc/network/interfaces was modified by pppoeconf

sudo vi /etc/network/interfaces