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Chapter 6
Troubleshooting TCP/IP Connectivity
Figure 6.12 displays a flowchart that depicts each step of the initialization
process. The process starts by sending out Hello packets. Every listening
router then adds the originating router to the adjacency database. The
responding routers reply with all of their Hello information so that the orig-
inating router can add them to its adjacency table.
Area identification
OSPF area number and link information, which
must be the same for a peering session to be
established.
Router priority
Value assigned to a router and used when choos-
ing the DR and BDR.
DR and BDR
If they have already been chosen, their Router ID
and address is contained in the Hello packet.
Authentication
password
All peers must have the same authentication pass-
word if authentication is enabled.
Stub area flag
This is a special area--two routers must share the
same stub information. This is not necessary to ini-
tiate a regular peering session with another OSPF
router.
T A B L E 6 . 9
OSPF Multicast Information (continued)
Information Description
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