Figure 7: Stub Area Example - Avaya 8600 Engineering

8.2.2 Stub Area
A stub area does not receive advertisements for external routes (AS-external LSAs, type 5) from an Area
Border Router, which reduces the size of the link state database. Instead, routing to external destinations
from within a stub area is based simply on the default route originated by a stub area border router. A
stub area has only one area border router. Any packets destined outside the area are simply routed to
that area border exit point where the packets are examined by the area border router and forwarded to a
destination. ASBR‟s cannot be supported within a stub area. Without AS-external LSA‟s, stub area‟s
cannot support virtual links.
8.2.2.1 Configuring a Stub Area
To configure an OSPF area as a stub or NSSA, use the following command
PP8600A# config ip ospf area <area IP address> stub <true | false>
PP8600A# config ip ospf area <area IP address> nssa <true | false>

AS-external LSA‟s are not flooded into a Stub area‟s. Instead, only one default route to external
destinations is distributed into the Stub area by the Stub ABR router
8.2.2.1.1 Configuration Example – Stub Area Configuration
The following are the configuration step required on PP8600E and PP8600B:
PP8600E Configuration Steps:
Step 1 Configure OSPF Interface
config ethernet 2/6 ip create 10.1.1.18/30
2090
config ethernet 2/6 ip ospf enable
November 2010

Figure 7: Stub Area Example

ERS 8600 / 8800 OSPF Technical Configuration Guide
These two command configure port 2/6 as a brouter port
and enables OSPF on this interface
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