An autonomous system, AS,, configured to operate as a system in a source-selected path routing network, including: a data plane, comprising one or more border routers, BRs, configured to receive path information from a first neighboring AS and to forward said path information to a control service, CS, a control plane, comprising said control service, CS, said CS configured to construct path segments by supplementing said path information by adding information about a plurality of links connecting the AS to the first neighboring AS and by registering the supplemented path information in order to make it available to local and remote hosts and to store the resulting path segments in a database, and further to propagate said supplemented path information to a second neighboring AS; wherein said data plane comprising the one or more BRs is further configured to forward data packets across a specific link selected from the plurality of links based on the constructed path segments, wherein the data plane and the control plane are split into a plurality of shards, each shard comprising one or more BRs and exactly one CS, and wherein the CS of each shard is configured to construct a shard of path segments by supplementing the received path information by adding information about a subset of the links connecting the AS to the first neighboring AS and by registering the supplemented path information in order to make it available to local and remote hosts and to store the resulting shard of path segments in a segment storage, and further to propagate said shard of supplemented path information to the second neighboring AS; and a local host, configured to send a query for information about available path segments for routing a data packet to a destination AS, wherein the local host comprises a daemon, configured to fetch the constructed shards of path segments from the CSes of all shards and to combine said fetched path segments to a path from the local host to the destination AS. a data plane, comprising one or more border routers, BRs, configured to receive path information from a first neighboring AS and to forward said path information to a control service, CS, a control plane, comprising said control service, CS, said CS configured to construct path segments by supplementing said path information by adding information about a plurality of links connecting the AS to the first neighboring AS and by registering the supplemented path information in order to make it available to local and remote hosts and to store the resulting path segments in a database, and further to propagate said supplemented path information to a second neighboring AS; wherein said data plane comprising the one or more BRs is further configured to forward data packets across a specific link selected from the plurality of links based on the constructed path segments, wherein the data plane and the control plane are split into a plurality of shards, each shard comprising one or more BRs and exactly one CS, and wherein the CS of each shard is configured to construct a shard of path segments by supplementing the received path information by adding information about a subset of the links connecting the AS to the first neighboring AS and by registering the supplemented path information in order to make it available to local and remote hosts and to store the resulting shard of path segments in a segment storage, and further to propagate said shard of supplemented path information to the second neighboring AS; and a local host, configured to send a query for information about available path segments for routing a data packet to a destination AS, wherein the local host comprises a daemon, configured to fetch the constructed shards of path segments from the CSes of all shards and to combine said fetched path segments to a path from the local host to the destination AS.