In one embodiment, a device receives a destination unreachable message originated by a particular node along a first source route, the message carrying an encapsulated packet as received by the particular node. In response, the device may determine a failed link along the first source route based on a tunnel header and the particular node. Once determining an alternate source route without the failed link, the device may re-encapsulate and re-transmit the original packet on an alternate source route with a new tunnel header indicating the alternate source route (e.g., and a new hop limit count for the tunnel header and an adjusted hop limit count in the original packet).