A method (300, 400) for route optimization that does not require a return routability procedure, the method comprising the steps of: (a) receiving, at a home agent, a first update message transmitted from a mobile node, the first update message comprising a care-of-address, CoA, associated with the mobile node, wherein, in response to receiving the first update message, the home agent binds the CoA associated with the mobile node with a home address assigned to the mobile node; and (b) after receiving the first update message, transmitting a second update message from the home agent to a correspondent node, the second update message comprising the CoA associated with the mobile node and the home address assigned to the mobile node; wherein the correspondent node is a mobile node and the correspondent node has the same home agent as the first recited mobile node; (c) receiving, at the home agent, a third update message transmitted from the correspondent node, the third update message comprising a CoA associated with the correspondent node, wherein, in response to receiving the third update message, the home agent binds the CoA associated with the correspondent node with a home address assigned to the correspondent node, wherein step (b) is not performed until after the home agent receives the third update message, (d) after receiving the third update message, determining whether there is a trusted relationship between the mobile node and the correspondent node; and (e) in response to determining that there is a trusted relationship between the two nodes, then transmitting to the mobile node the CoA associated with the correspondent node and transmitting to the correspondent node the said second update message of step (b), wherein the step of determining whether there is a trusted relationship between the mobile node and the correspondent node comprises determining whether there is a cryptographic relationship between the mobile node and the correspondent node, and wherein steps (d) and (e) are performed by the home agent. (a) receiving, at a home agent, a first update message transmitted from a mobile node, the first update message comprising a care-of-address, CoA, associated with the mobile node, wherein, in response to receiving the first update message, the home agent binds the CoA associated with the mobile node with a home address assigned to the mobile node; and (b) after receiving the first update message, transmitting a second update message from the home agent to a correspondent node, the second update message comprising the CoA associated with the mobile node and the home address assigned to the mobile node; (c) receiving, at the home agent, a third update message transmitted from the correspondent node, the third update message comprising a CoA associated with the correspondent node, wherein, in response to receiving the third update message, the home agent binds the CoA associated with the correspondent node with a home address assigned to the correspondent node, wherein step (b) is not performed until after the home agent receives the third update message, (d) after receiving the third update message, determining whether there is a trusted relationship between the mobile node and the correspondent node; and (e) in response to determining that there is a trusted relationship between the two nodes, then transmitting to the mobile node the CoA associated with the correspondent node and transmitting to the correspondent node the said second update message of step (b), wherein