A method for communication includes configuring a router to forward data packets over a network in accordance with Multiprotocol Label Switching (MPLS) labels appended to the data packets. At least first and second entries, corresponding to respective first and second labels, are stored in a Next Hop Label Forwarding Entry (NHLFE) table in the router, such that each of the first entries contains a respective pointer to at least one of the second entries. Upon receiving in the router a data packet from the network, a first entry is selected from among the first entries in the NHLFE table and, responsively to the pointer in the first entry, a second entry is selected. The respective first and second labels from the selected first and second entries are pushed onto an MPLS label stack of the data packet.