The present invention relates to a communication system comprising a number of end user stations (hosts) connected over access networks and routing arrangements. The system supports a IPv6 (Internet Protocol version 6) addressing scheme, wherein the end user stations are connected to the routing arrangements over links, and sending of router advertisements from router arrangements to end user stations (hosts) being implemented to support provisioning of IPv6 addresses for the end user station. Router advertisements (RAs) from a routing arrangement to an end user station are sent with a controllable and variable frequency during an initial phase. During said initial phase, the frequency is higher at the beginning and lower at the end.