ZHLS GF

ZHLS-GF (Zone-Based Hierarchical Link State Routing Protocol with Gateway Flooding) is a hybrid routing protocol based on ZHLS. In ZHLS, all network nodes construct two routing tables, an intra-zone routing table and an inter-zone routing table, by flooding NodeLSPs within the zone and ZoneLSPs throughout the network. However, this incurs a large communication overhead in the network. In ZHLS-GF, the flooding scheme floods ZoneLSPs only to the gateway nodes of zones thus reduces the communication overhead significantly. Further, in ZHLS-GF only the gateway nodes store ZoneLSPs and construct inter-zone routing tables therefore the total storage capacity required in the network is less than ZHLS.