I moved to Luxembourg and I have opted for Tango Fiber. Their router is a Fritz!box which I do not like at all. I have a spare Mikrotik router, so here is how to configure.
Tango Fiber uses PPPoE over VLAN 35, MTU is 1480. You need to ask the PPP credentials via a contact form on the website, they will answer within a few days.
I have decided to use
ether1 to connect the Fiber and create a VLAN interface named
ether1.35 on it.
/interface vlan add interface=ether1 name=ether1.35 vlan-id=35 /interface pppoe-client add add-default-route=yes default-route-distance=0 disabled=no interface=ether1.35 max-mtu=1480 \ name=TangoFibre password=xxx use-peer-dns=yes user=xxx@tango
Do not forget to adapt your NAT rules to allow exit through this interface.