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On PTMP subnets Hello protocol is used only to detect active OSPF neighbors and to detect bidirectional communication between neighbors. Routers on PTMP subnets send Hello packets to all other routers that are directly connected to them. Designated Routers and Backup Designated Routers are not elected on Point-to-multipoint subnets.
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| In ROS version 7 static neighbors must be configured for PTPM networks. |
Master-Slave Relation
Before database synchronization can begin, a hierarchy order of exchanging information must be established, which determines which router sends Database Descriptor (DD) packets first (Master). Master router is elected based on highest priority and if priority is not set then router ID will be used. Note that it is a router priority-based relation to arranging the exchanging data between neighbors which does not affect DR/BDR election (meaning that DR does not always have to be Master).
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