1. A method, comprising: pre-computing diverse source-routed paths to one or more nodes in a computer network by a source routing device; receiving a particular packet at the device; forwarding the particular packet on a source-routed first path of the pre-computed diverse paths; implicitly detecting failure of the first path by the device; and forwarding a copy of the particular packet on a source-routed second path of the pre-computed diverse paths in response to the implicitly detected failure of the first path.