In an embodiment, a method comprises: determining that a session restart on a restarting node has been initiated; in response to determining that the restarting node has preserved a last acknowledged version of routing information received from a peer node, and determining that the restarting node has preserved a routing state corresponding to the last acknowledged version of routing information, transmitting to the peer node a message indicating that the last acknowledged version of routing information and the routing state have been preserved at the restarting node; wherein the method is performed by one or more computing devices.