A method and Access Network Node for handling dissimilar protocols when a Host accesses a Broadband Network. The Access Network Node includes a protocol converter for interworking between the Neighbor Discovery (ND) protocol and the Dynamic Host Configuration Protocol (DHCP). When an ND Router Solicitation message is received from a Host that does not support DHCP, the converter converts the ND message to a DHCP Solicit message and forwards it to a Broadband Network Gateway (BNG) together with a port ID. When the Access Network Node receives a DHCP Reply message from the BNG destined for the same Host, the converter converts the DHCP Reply message to an ND Router Advertisement message before sending it to the Host.