A method for re-routing traffic in a network topology based on Shortest Path First, SPF, calculations, the network comprising a plurality of nodes (101 - 107), a traffic source 'Src' and a traffic destination 'Dest', wherein a path of nodes (105, 104, 101) represents a shortest source-to-destination path for the traffic from the traffic source to the traffic destination, and wherein each node has pre-calculated a shortest node-to-destination path from the respective node to the traffic destination, the method being performed in a first node 'A' of two nodes and comprising the steps of: receiving, from a second node 'S' at the first node, a notification indicating a loss of connection to a third node 'E' belonging to the shortest source-to-destination path, the first node being a next-hop of the second node; and selecting, at the first node, a neighbouring node as a new next-hop whose shortest node-to-destination path does not cross the connection-lost node wherein: the notification is an explicit notification message, is received at the first node 'A', and indicates failure of the second node 'S' losing connectivity to the third node 'E', the first node 'A' performs the selecting step so as to select a fourth neighbouring node 'N' (106, 107) as an alternate that does not require explicit notification due to its pre-calculated node-to-destination path being the shortest node-to-destination path irrespective of the node failure, and the selecting step further selects, responsive to the receiving of the explicit notification message of the second node 'S' losing connectivity to the third node 'E', the fourth neighbouring node 'N' as an alternate if and only if: Distance(fourth node N, Dest) < Distance(fourth node N, second node S) + Distance(second node S, Dest). receiving, from a second node 'S' at the first node, a notification indicating a loss of connection to a third node 'E' belonging to the shortest source-to-destination path, the first node being a next-hop of the second node; and selecting, at the first node, a neighbouring node as a new next-hop whose shortest node-to-destination path does not cross the connection-lost node wherein: the notification is an explicit notification message, is received at the first node 'A', and indicates failure of the second node 'S' losing connectivity to the third node 'E', the first node 'A' performs the selecting step so as to select a fourth neighbouring node 'N' (106, 107) as an alternate that does not require explicit notification due to its pre-calculated node-to-destination path being the shortest node-to-destination path irrespective of the node failure, and the selecting step further selects, responsive to the receiving of the explicit notification message of the second node 'S' losing connectivity to the third node 'E', the fourth neighbouring node 'N' as an alternate if and only if: Distance(fourth node N, Dest) < Distance(fourth node N, second node S) + Distance(second node S, Dest). the notification is an explicit notification message, is received at the first node 'A', and indicates failure of the second node 'S' losing connectivity to the third node 'E', the first node 'A' performs the selecting step so as to select a fourth neighbouring node 'N' (106, 107) as an alternate that does not require explicit notification due to its pre-calculated node-to-destination path being the shortest node-to-destination path irrespective of the node failure, and the selecting step further selects, responsive to the receiving of the explicit notification message of the second node 'S' losing connectivity to the third node 'E', the fourth neighbouring node 'N' as an alternate if and only if: Distance(fourth node N, Dest) < Distance(fourth node N, second node S) + Distance(second node S, Dest). Distance(fourth node N, Dest) < Distance(fourth node N, second node S) + Distance(second node S, Dest).