Vodafone forces its customers to use their modem/router, the "Vodafone Station": using any other router is impossible because authentication is being done via a custom PPPoE setup.
In the PPPoE packet there is a field named Host-Uniq which is used to separate packets from different PPPoE sessions: Vodafone requires the Station serial number to be put in this field as authentication.
A Linux router with root access is needed to replace the Station with. With an xDSL connection a modem with a custom firmware like OpenWrt has to be used, most likely one based on a Lantiq SoC.
For a FTTH internet connection then every machine with at least two gigabit ethernet interface and a decent CPU will do it.
