Administrator's Guide v4.1.1 Manual

FIGURE 61 OSPF operating in a network
NOTE
For details of components and virtual links, refer to OSPF components and roles on page 584 and
Virtual links on page 588, respectively.
Once OSPF is enabled on the system, the user assigns an IP address or number as the area ID for
each area. The area ID is representative of all IP addresses (subnets) on a router port. Each port on a
router can support one area.
OSPF components and roles
Routers can take a variety of roles in an OSPF topology, as discussed below.
Area Border Routers
An OSPF router can be a member of multiple areas. Routers with membership in multiple areas are
known as Area Border Routers (ABRs) Each ABR maintains a separate topological database for each
area the router is in. Each topological database contains all LSA databases for each router within a
OSPF components and roles
584 Network OS Administrator’s Guide
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