![background image](http://html.mh-extra.com/html/cisco/5505-asa-firewall-edition-bundle/5505-asa-firewall-edition-bundle_cli-configuration-manual_18624645.webp)
1-13
Cisco ASA Series CLI Configuration Guide
Chapter 1 Configuring OSPF
Customizing OSPFv2
Configuring an OSPFv2 NSSA
The OSPFv2 implementation of an NSSA is similar to an OSPFv2 stub area. NSSA does not flood Type
5 external LSAs from the core into the area, but it can import autonomous system external routes in a
limited way within the area.
NSSA imports Type 7 autonomous system external routes within an NSSA area by redistribution. These
Type 7 LSAs are translated into Type 5 LSAs by NSSA ABRs, which are flooded throughout the whole
routing domain. Summarization and filtering are supported during the translation.
You can simplify administration if you are an ISP or a network administrator that must connect a central
site using OSPFv2 to a remote site that is using a different routing protocol with NSSA.
Before the implementation of NSSA, the connection between the corporate site border router and the
remote router could not be run as an OSPFv2 stub area because routes for the remote site could not be
redistributed into the stub area, and two routing protocols needed to be maintained. A simple protocol
such as RIP was usually run and handled the redistribution. With NSSA, you can extend OSPFv2 to
cover the remote connection by defining the area between the corporate router and the remote router as
an NSSA.
Before you use this feature, consider these guidelines:
•
You can set a Type 7 default route that can be used to reach external destinations. When configured,
the router generates a Type 7 default into the NSSA or the NSSA area boundary router.
•
Every router within the same area must agree that the area is NSSA; otherwise, the routers cannot
communicate with each other.
area
area-id
authentication
Example:
hostname(config-rtr)# area 0
authentication
Enables authentication for an OSPF area.
area
area-id
authentication message-digest
Example:
hostname(config-rtr)# area 0
authentication message-digest
Enables MD5 authentication for an OSPF area.
Command
Purpose
Summary of Contents for 5505 - ASA Firewall Edition Bundle
Page 28: ...Glossary GL 24 Cisco ASA Series CLI Configuration Guide ...
Page 61: ...P A R T 1 Getting Started with the ASA ...
Page 62: ......
Page 219: ...P A R T 2 Configuring High Availability and Scalability ...
Page 220: ......
Page 403: ...P A R T 2 Configuring Interfaces ...
Page 404: ......
Page 499: ...P A R T 2 Configuring Basic Settings ...
Page 500: ......
Page 533: ...P A R T 2 Configuring Objects and Access Lists ...
Page 534: ......
Page 601: ...P A R T 2 Configuring IP Routing ...
Page 602: ......
Page 745: ...P A R T 2 Configuring Network Address Translation ...
Page 746: ......
Page 845: ...P A R T 2 Configuring AAA Servers and the Local Database ...
Page 846: ......
Page 981: ...P A R T 2 Configuring Access Control ...
Page 982: ......
Page 1061: ...P A R T 2 Configuring Service Policies Using the Modular Policy Framework ...
Page 1062: ......
Page 1093: ...P A R T 2 Configuring Application Inspection ...
Page 1094: ......
Page 1191: ...P A R T 2 Configuring Unified Communications ...
Page 1192: ......
Page 1333: ...P A R T 2 Configuring Connection Settings and QoS ...
Page 1334: ......
Page 1379: ...P A R T 2 Configuring Advanced Network Protection ...
Page 1380: ......
Page 1475: ...P A R T 2 Configuring Modules ...
Page 1476: ......
Page 1549: ...P A R T 2 Configuring VPN ...
Page 1550: ......
Page 1965: ...P A R T 2 Configuring Logging SNMP and Smart Call Home ...
Page 1966: ......
Page 2059: ...P A R T 2 System Administration ...
Page 2060: ......
Page 2098: ...1 8 Cisco ASA Series CLI Configuration Guide Chapter 1 Troubleshooting Viewing the Coredump ...
Page 2099: ...P A R T 2 Reference ...
Page 2100: ......