D-Link DES-3326SRM Product Manual - Page 175

The Database Description Packet

Page 175 highlights

D-Link DES-3326S Layer 3 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 Table 6. 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 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. The 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 poll-response procedure is used. One of the routers is designated to be master, the other a slave. The master seconds Database Description packets (polls) which are acknowledged by Database Description packets sent by the slave (responses). The responses are linked to the polls via the packets' DD sequence numbers. 165

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D-Link DES-3326S Layer 3 Switch
Hello Packet
1
Packet Length
Router ID
Area ID
Version No.
Checksum
Authentication Type
Authentication
Authentication
Network Mask
Hello Interval
Options
Router Priority
Router Dead Interval
Designated Router
Backup Designated Router
Neighbor
Table 6. Hello Packet
Field
Description
Network Mask
The network mask associated with this interface.
Options
The optional capabilities supported by the router.
Hello Interval
The number of seconds between this router’s Hello packets.
Router Priority
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
become the DR or the BDR.
Router Dead Interval
The number of seconds that must pass before declaring a silent
router as down.
Designated Router
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.
Backup Designated Router
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.
Field
Description
Neighbor
The Router Ids of each router from whom valid Hello packets
have been seen within the Router Dead Interval on the network.
The 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 poll-response procedure is used.
One of the routers is designated to be master, the other a slave.
The master seconds
Database Description packets (polls) which are acknowledged by Database Description packets sent by the slave (responses).
The responses are linked to the polls via the packets’ DD sequence numbers.
165