A method of facilitating Internet Protocol access by a mobile node to an access Network, the method comprising: sending an attachment request from the mobile node to an access router of the access network, the request containing a mobile node identifier and an Interface Identifier or means for deriving an Interface Identifier, and being signed by the mobile node to allow the message to be authenticated as originating at that mobile node; receiving the request at the access router and authenticating the message there using the signature, and in response to the receipt and authentication of the message, performing a predefined set of tasks delegated to the access node and which are required to facilitate said access; and returning an acknowledgment from the access router to the mobile node confirming the access permission, the acknowledgement containing a network routing prefix and means for authenticating the access router to the mobile node.