1. A method, comprising: receiving, at an intermediate node of a computer network, a first message intended for a destination, the first message having a header indicating a source route, wherein a route cache indicator is included within the header that triggers the intermediate node to cache a routing entry and indicates for how long to cache the routing entry; in response to the route cache indicator being within the first message: determining, by the intermediate node, the routing entry for the destination, the routing entry associated with a next hop of the intermediate node toward the destination based on the source route, wherein the routing entry is a portion of the source route to the destination, and caching the routing entry at the intermediate node; receiving a second message intended for the destination at the intermediate node, wherein the second message does not indicate the next hop; and transmitting, by the intermediate node, the second message according to the cached routing entry to the next hop associated with the destination.