I have not been able to find a way to assign the default route inserted via pppoe-client to a specific routing table.
In v6.x I use this hack because adding a pppoe-client to a VRF results in the default still going to ‘main’
/routing/filter add chain=dynamic-in comment="Hack to add routing mark for pppoe" distance=104 set-routing-mark=DSL
The pppoe client sets the distance to ‘104’ and the route filter assigns the route to the DSL table based on that.
In v7.1 adding the pppoe-client interface to a VRF as below still results in the default added to the ‘main’ table and there doesn’t appear to be a way to apply the workaround above. Adding the underlying interface to the VRF doesn’t work either, unlike adding the underlying interface for a dhcp-client.
/ip/vrf add interfaces=pppoe-interface name=DSL
Totally open to other options if they exist