Ospf Configuration Concerns - HP 7102dl - ProCurve Secure Router Configuration Manual

Depending on the type of LSAs that the router receives, the database can also
include:
links to ranges of networks in other areas
links to external networks
The router would use this information to generate inter-area and external
routes.
A router applies the Dijkstra's algorithm to its topological database to generate
a routing tree with itself as the root. This action is also called performing the
shortest path first (SPF) calculation. From the SPF tree, the router calculates
its own best routes. Each router's routing table is unique. Each route in this
table contains this information:
type of route—O, IA, E1, or E2
destination address and subnet mask
administrative distance—by default, 110 for OSPF routes
metric—the total cost for all links in between the router and the
destination
next-hop address
Because OSPF routers can factor in the total cost for all links between the
router and the destination, they can use higher-speed connections, even when
they involve more hops.
A router performs SPF calculations when its OSPF database changes. Its SPF
calculation delay and hold timers prevent the router from performing the
calculation too often. These factors prevent router processes from being tied
up when, for example, a flapping interface causes continual topological
changes. (A flapping interface is a term used for interfaces that frequently
change their status from up to down and then down to up.)

OSPF Configuration Concerns

Properly configuring areas is a large part of configuring OSPF. Before you
configure OSPF on your ProCurve Secure Router, you should have a clear
picture of your network's topology. You should know:
each router's role:
• internal router
• ABR
• ASBR
each router's ID
the OSPF area for each directly connected network
IP Routing—Configuring RIP, OSPF, BGP, and PBR
Configuring OSPF
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