Configuring OSPF
433
In the following group network, an AS operating the OSPF protocol includes three
areas, area 1, area 2, and area 0. Area 0 is the backbone area. The other ASs
operate RIP. Area 1 is defined as an NSSA area. After an RIP route advertises to the
NSSA ASBR that generates a Type-7 LSA and propagates in Area 1. After the
Type-7 LSA reaches the NSSA ABR, it is transformed into a Type-5 LSA that is
advertised to Area 0 and Area 2. The RIP route is generated as a Type-5 LSA and
propagated in the OSPF AS by the ASBR of Area 2. This Type-5 LSA will not reach
Area 1 because Area 1 is an NSSA area. On this point, an NSSA area and a stub
area are the same.
Figure 146
Schematic Diagram of an NSSA Area
Perform the following configuration in OSPF view:
Table 499
Configure an NSSA Area of OSPF
By default, no area is configured as an NSSA area.
The
default-route-advertise
attribute generates default a Type-7 LSA. A
Type-7 LSA default route is generated on the ABR no matter whether there is a
default route 0.0.0.0 in the routing table while applying this parameter. A Type-7
LSA default route is only generated on an ASBR when there is a default route
0.0.0.0 in the routing table.
The
no-import-route
attribute is used on the ASBR, which allows the OSPF route
that is imported using the
import-route
command, to not be advertised to the
NSSA area. If the NSSA router is both ASBR and ABR, this parameter option is
always selected.
Configuring Route
Summarization within
the OSPF Domain
.
Route summary provides that the routing information is processed in the ABR.
Only one route is sent to other areas for the network segment configured with
summary. One area can be configured with multiple summary network segments
so that OSPF can summarize multiple network segments. When the ABR sends
routing information to other areas, Sum_net_Lsa (Type 3 LSA) is generated for
each network segment. If there are some continuous network segments in the
area, they can be summarized into one network segment with a range command.
Then the ABR only sends one summery LSA and all other LSAs in the summary
network segment range specified with this command are not sent separately,
Operation
Command
Configure an area as NSSA area
nssa area
area-id
[
default-route-advertise ] [
no-import-route ] [ no-summary ]
Cancel the configured NSSA area
undo nssa area
area-id
area 0
area 1
NSSA
Router
area 2
Router
Router
RIP
Router
Router
RIP
NSSA
ASBR
NSSA
ABR
Содержание 3036
Страница 1: ...http www 3com com 3Com Router Configuration Guide Published March 2004 Part No 10014299 ...
Страница 4: ...VPN 615 RELIABILITY 665 QOS 681 DIAL UP 721 ...
Страница 6: ...2 ABOUT THIS GUIDE ...
Страница 7: ...I GETTING STARTED Chapter 1 3Com Router Introduction Chapter 2 3Com Router User Interface ...
Страница 8: ...4 ...
Страница 16: ...12 CHAPTER 1 3COM ROUTER INTRODUCTION ...
Страница 34: ...30 ...
Страница 60: ...56 CHAPTER 3 SYSTEM MANAGEMENT ...
Страница 88: ...84 CHAPTER 5 CONFIGURING NETWORK MANAGEMENT RouterA interface ethernet 0 RouterA Ethernet0 rmon promiscuous ...
Страница 98: ...94 CHAPTER 6 DISPLAY AND DEBUGGING TOOLS ...
Страница 110: ...106 ...
Страница 114: ...110 CHAPTER 8 INTERFACE CONFIGURATION OVERVIEW ...
Страница 158: ...154 CHAPTER 10 CONFIGURING WAN INTERFACE ...
Страница 168: ...164 ...
Страница 188: ...184 CHAPTER 13 CONFIGURING PPPOE CLIENT ...
Страница 192: ...188 CHAPTER 14 CONFIGURING SLIP Router ip route static 0 0 0 0 0 0 0 0 10 110 0 1 ...
Страница 248: ...244 CHAPTER 16 CONFIGURING LAPB AND X 25 ...
Страница 292: ...288 CHAPTER 18 CONFIGURING HDLC Enable HDLC packet debugging debugging hdlc packet interface type number ...
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Страница 330: ...326 CHAPTER 20 CONFIGURING IP ADDRESS ...
Страница 362: ...358 CHAPTER 21 CONFIGURING IP APPLICATION ...
Страница 374: ...370 CHAPTER 23 CONFIGURING IP COUNT ...
Страница 406: ...402 CHAPTER 25 CONFIGURING DLSW ...
Страница 408: ...404 ...
Страница 452: ...448 CHAPTER 29 CONFIGURING OSPF ...
Страница 482: ...478 CHAPTER 30 CONFIGURING BGP ...
Страница 494: ...490 CHAPTER 31 CONFIGURING IP ROUTING POLICY ...
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Страница 508: ...504 CHAPTER 33 IP MULTICAST ...
Страница 514: ...510 CHAPTER 34 CONFIGURING IGMP ...
Страница 526: ...522 CHAPTER 36 CONFIGURING PIM SM ...
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Страница 532: ...528 CHAPTER 37 CONFIGURING TERMINAL ACCESS SECURITY ...
Страница 550: ...546 CHAPTER 38 CONFIGURING AAA AND RADIUS PROTOCOL ...
Страница 590: ...586 CHAPTER 40 CONFIGURING IPSEC ...
Страница 599: ...IX VPN Chapter 42 Configuring VPN Chapter 43 Configuring L2TP Chapter 44 Configuring GRE ...
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Страница 638: ...634 CHAPTER 43 CONFIGURING L2TP ...
Страница 649: ...X RELIABILITY Chapter 45 Configuring a Standby Center Chapter 46 Configuring VRRP ...
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Страница 670: ...666 CHAPTER 47 QOS OVERVIEW ...
Страница 700: ...696 CHAPTER 49 CONGESTION MANAGEMENT ...
Страница 706: ...702 CHAPTER 50 CONGESTION AVOIDANCE ...
Страница 707: ...XII DIAL UP Chapter 51 Configuring DCC Chapter 52 Configuring Modem ...
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Страница 762: ...758 CHAPTER 52 CONFIGURING MODEM ...