D-Link DGS-3627 Product Manual - Page 221

xStack® DGS-3600 Series Layer 3 Managed Gigabit Ethernet Switch Hello Packet Version No. 1 Packet Length Router ID Area ID Checksum Authentication Type Authentication Authentication Network Mask Hello Interval Options Router Priority Router Dead Interval Designated Router Backup Designated Router Neighbor Figure 4- 40. Hello Packet Field Network Mask Options Hello Interval Router Priority Router Dead Interval Designated Router Backup Designated Router Field Neighbor Description The network mask associated with this interface. The optional capabilities supported by the router. The number of seconds between this router's Hello packets. This router's Router Priority. The Router Priority is used in the election of the DR and BDR. If this field is set to 0, the router is ineligible to become the DR or the BDR. The number of seconds that must pass before declaring a silent router as down. The identity of the DR for this network, in the view of the advertising router. The DR is identified here by its IP interface address on the network. The identity of the Backup Designated Router (BDR) for this network. The BDR is identified here by its IP interface address on the network. This field is set to 0.0.0.0 if there is no BDR. Description The Router IDs of each router from whom valid Hello packets have been seen within the Router Dead Interval on the network. Database Description Packet Database Description packets are OSPF packet type 2. These packets are exchanged when an adjacency is being initialized. They describe the contents of the topological database. Multiple packets may be used to describe the database. For this purpose, a pollresponse procedure is used. One of the routers is designated to be master, the other a slave. The master seconds Database Description packets (polls) that are acknowledged by Database Description packets sent by the slave (responses). The responses are linked to the polls via the packets' DD sequence numbers. 205