Juniper IGP - CONFIGURATION GUIDE V11.1.X Configuration Manual page 277

network area
NOTE: Until you activate the configured network range for summaries by issuing the
area range command, the range is not active for summarization; the network range
is summarized through area summaries for ABRs only. (See "Aggregating OSPF
Networks" on page 256 .) The only range that is active by default if you do not issue
the area range command is the network that matches the IP interface's network
exactly. (In other words, by default the exact network of the IP interface is going to
be summarized into other areas.)
ospf enable
Use to configure a range of OSPFv2 interfaces and their related area.
If the specified range matches one or more of the IP addresses configured for
IP interfaces, one or more corresponding OSPF interfaces are created and placed
in the specified area.
Create address ranges that do not overlap; you can attach only the same range
of interfaces to a single area.
You cannot use this command for unnumbered interfaces.
If the range specified by this command includes an address on an interface that
is being referred to by unnumbered interfaces, all of the unnumbered interfaces
begin trying to form adjacencies. If this behavior is not intended, you must
reevaluate the interface assignment or the range specified by the command.
Example 1 shows the creation of one OSPF interface in the backbone area
host1(config-if)#ip address 2.2.2.1 255.255.0.0
host1(config-if)#ip address 2.2.1.1 255.255.0.0 secondary
host1(config)#router ospf 2
host1(config-router)#network 2.2.2.0 0.0.0.255 area 0
Example 2 shows the creation of two OSPF interfaces, one in the backbone
area and one in a non-backbone area
host1(config-if)#ip address 2.2.2.1 255.255.255.0
host1(config-if)#ip address 2.2.1.1 255.255.255.0 secondary
host1(config)#router ospf 2
host1(config-router)#network 2.2.2.0 0.0.0.255 area 0
host1(config-router)#network 2.2.1.0 0.0.0.255 area 1
This sequence of commands creates two OSPF ranges (2.2.2.0/24 and 2.2.1.0/24),
with each range belonging to a different area. Area 0 is configured for 2.2.2.0/24,
and area 1 is configured for 2.2.1.0/24. This sequence also creates two OSPF
interfaces: one in the backbone area (area 0) using IP address 2.2.2.1, the second
in a nonbackbone area (area 1) using IP address 2.2.1.1. This command also
creates the two areas if they do not already exist.
Use the no version to delete OSPF interfaces, ranges, and areas.
See network area
Chapter 5: Configuring OSPF
253
Starting OSPF