D-Link xStack Reference Manual page 213

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xStack DGS-3620 Series Layer 3 Managed Stackable Gigabit Switch Web UI Reference Guide
Interval, and the Router Dead Interval. These parameters are included in the hello packets, so that differences can
inhibit the forming of neighbor relationships. A detailed explanation of the receive process for Hello packets is
necessary so that differences cannot inhibit the forming of neighbor relationships.
The format of the Hello packet is shown below:
Version No.
Parameter
Network Mask
Options
Hello Interval
Router Priority
Router Dead Interval
Designated Router
Backup Designated
Router
Neighbor
Database Description Packet
Hello Packet
1
Checksum
Hello Interval
Router Dead Interval
Designated Router
Backup Designated Router
Figure 6-30 Hello Packet
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.
The Router IDs of each router from whom valid Hello packets have been seen within
the Router Dead Interval on the network.
Packet Length
Router ID
Area ID
Authentication Type
Authentication
Authentication
Network Mask
Options
Neighbor
212
Router Priority