实验拓扑
实验任务
- 设备IP地址配置。
- 按照规划配置 OSPF区域。
- 检查OSPF配置结果，检查OSPF邻居关系状态，检查OSFP路由表。
- 在R1、R4上将外部路由引入到OSPF中。
- 配置区域3为Stub区域，观察区域3内OSPF路由表、LSDB的变化。
- 配置区域1为NSSA区域，观察区域1内OSPF路由表、LSDB的变化。
- 查看R4的OSPF路由器身份，在 R4上观察Type-7 LSA向Type-5 LSA的转换。
实验步骤
接口配置和OSPF区域配置
以R2为例：
java
interface GigabitEthernet0/0/0
ip address 10.1.12.2 255.255.255.252
ospf network-type p2p
#
interface GigabitEthernet0/0/1
ip address 10.1.23.1 255.255.255.252
ospf network-type p2p
#
interface GigabitEthernet0/0/2
ip address 10.1.25.1 255.255.255.252
ospf network-type p2p
#
interface LoopBack0
ip address 10.0.2.2 255.255.255.255
#
ospf 1 router-id 10.0.2.2
area 0.0.0.0
network 10.0.2.2 0.0.0.0
network 10.1.23.1 0.0.0.0
area 0.0.0.2
network 10.1.12.2 0.0.0.0
area 0.0.0.3
network 10.1.25.1 0.0.0.0 检查邻居关系和路由
java
<R2>display ospf peer brief
OSPF Process 1 with Router ID 10.0.2.2
Peer Statistic Information
----------------------------------------------------------------------------
Area Id Interface Neighbor id State
0.0.0.0 GigabitEthernet0/0/1 10.0.3.3 Full
0.0.0.2 GigabitEthernet0/0/0 10.0.1.1 Full
0.0.0.3 GigabitEthernet0/0/2 10.0.5.5 Full
----------------------------------------------------------------------------
<R2>display ospf routing
OSPF Process 1 with Router ID 10.0.2.2
Routing Tables
Routing for Network
Destination Cost Type NextHop AdvRouter Area
10.0.2.2/32 0 Stub 10.0.2.2 10.0.2.2 0.0.0.0
10.1.12.0/30 1 Stub 10.1.12.2 10.0.2.2 0.0.0.2
10.1.23.0/30 1 Stub 10.1.23.1 10.0.2.2 0.0.0.0
10.1.25.0/30 1 Stub 10.1.25.1 10.0.2.2 0.0.0.3
10.0.3.3/32 1 Stub 10.1.23.2 10.0.3.3 0.0.0.0
10.0.5.5/32 1 Stub 10.1.25.2 10.0.5.5 0.0.0.3
10.1.34.0/30 2 Inter-area 10.1.23.2 10.0.3.3 0.0.0.0 在R1、R4上将外部路由引入到OSPF中
java
ospf 1 router-id 10.0.4.4
import-route direct 在R5观察路由表和LSDB：
java
<R5>display ospf routing
OSPF Process 1 with Router ID 10.0.5.5
Routing Tables
Routing for Network
Destination Cost Type NextHop AdvRouter Area
10.0.5.5/32 0 Stub 10.0.5.5 10.0.5.5 0.0.0.3
10.1.25.0/30 1 Stub 10.1.25.2 10.0.5.5 0.0.0.3
10.0.2.2/32 1 Inter-area 10.1.25.1 10.0.2.2 0.0.0.3
10.0.3.3/32 2 Inter-area 10.1.25.1 10.0.2.2 0.0.0.3
10.1.12.0/30 2 Inter-area 10.1.25.1 10.0.2.2 0.0.0.3
10.1.23.0/30 2 Inter-area 10.1.25.1 10.0.2.2 0.0.0.3
10.1.34.0/30 3 Inter-area 10.1.25.1 10.0.2.2 0.0.0.3
Routing for ASEs
Destination Cost Type Tag NextHop AdvRouter
10.0.1.1/32 1 Type2 1 10.1.25.1 10.0.1.1
10.0.4.4/32 1 Type2 1 10.1.25.1 10.0.4.4
Total Nets: 9
Intra Area: 2 Inter Area: 5 ASE: 2 NSSA: 0
<R5>display ospf lsdb
OSPF Process 1 with Router ID 10.0.5.5
Link State Database
Area: 0.0.0.3
Type LinkState ID AdvRouter Age Len Sequence Metric
Router 10.0.5.5 10.0.5.5 643 60 80000005 0
Router 10.0.2.2 10.0.2.2 644 48 80000002 1
Sum-Net 10.1.23.0 10.0.2.2 902 28 80000001 1
Sum-Net 10.1.34.0 10.0.2.2 787 28 80000001 2
Sum-Net 10.1.12.0 10.0.2.2 902 28 80000001 1
Sum-Net 10.0.3.3 10.0.2.2 796 28 80000001 1
Sum-Net 10.0.2.2 10.0.2.2 902 28 80000001 0
Sum-Asbr 10.0.4.4 10.0.2.2 734 28 80000001 2
Sum-Asbr 10.0.1.1 10.0.2.2 902 28 80000001 1
AS External Database
Type LinkState ID AdvRouter Age Len Sequence Metric
External 10.0.4.4 10.0.4.4 736 36 80000001 1
External 10.0.1.1 10.0.1.1 1024 36 80000001 1
External 10.1.12.0 10.0.1.1 1024 36 80000001 1
External 10.1.34.0 10.0.4.4 736 36 80000001 1 配置Stub区域
在R2和R5配置区域3为Stub区域,以R5为例：
java
ospf 1 router-id 10.0.5.5
area 0.0.0.3
network 10.0.5.5 0.0.0.0
network 10.1.25.2 0.0.0.0
stub 观察R5的路由表和LSDB
java
<R5>display ospf routing
OSPF Process 1 with Router ID 10.0.5.5
Routing Tables
Routing for Network
Destination Cost Type NextHop AdvRouter Area
10.0.5.5/32 0 Stub 10.0.5.5 10.0.5.5 0.0.0.3
10.1.25.0/30 1 Stub 10.1.25.2 10.0.5.5 0.0.0.3
0.0.0.0/0 2 Inter-area 10.1.25.1 10.0.2.2 0.0.0.3
10.0.2.2/32 1 Inter-area 10.1.25.1 10.0.2.2 0.0.0.3
10.0.3.3/32 2 Inter-area 10.1.25.1 10.0.2.2 0.0.0.3
10.1.12.0/30 2 Inter-area 10.1.25.1 10.0.2.2 0.0.0.3
10.1.23.0/30 2 Inter-area 10.1.25.1 10.0.2.2 0.0.0.3
10.1.34.0/30 3 Inter-area 10.1.25.1 10.0.2.2 0.0.0.3
Total Nets: 8
Intra Area: 2 Inter Area: 6 ASE: 0 NSSA: 0
<R5>display ospf lsdb
OSPF Process 1 with Router ID 10.0.5.5
Link State Database
Area: 0.0.0.3
Type LinkState ID AdvRouter Age Len Sequence Metric
Router 10.0.5.5 10.0.5.5 85 60 80000003 0
Router 10.0.2.2 10.0.2.2 86 48 80000003 1
Sum-Net 0.0.0.0 10.0.2.2 106 28 80000001 1
Sum-Net 10.1.23.0 10.0.2.2 106 28 80000001 1
Sum-Net 10.1.34.0 10.0.2.2 106 28 80000001 2
Sum-Net 10.1.12.0 10.0.2.2 106 28 80000001 1
Sum-Net 10.0.3.3 10.0.2.2 106 28 80000001 1
Sum-Net 10.0.2.2 10.0.2.2 106 28 80000001 0 此时，R5路由器不存在4/5类的LSA，由ABR（R2）产生一条三类LSA泛洪默认路由，指向ABR本身。
同时在R3区域内也不能引入外部路由,引入不生效。
java
ip route-static 0.0.0.0 0.0.0.0 LoopBack 0
ospf 1 router-id 10.0.5.5
import-route static配置NSSA区域
在R3和R4区域1配置NSSA区域
java
ospf 1 router-id 10.0.4.4
import-route direct
area 0.0.0.1
network 10.1.34.2 0.0.0.0
nssa
# 在R4观察路由表和LSDB
java
<R4>display ospf lsdb
OSPF Process 1 with Router ID 10.0.4.4
Link State Database
Area: 0.0.0.1
Type LinkState ID AdvRouter Age Len Sequence Metric
Router 10.0.3.3 10.0.3.3 17 36 80000004 1
Router 10.0.4.4 10.0.4.4 16 36 80000005 1
Network 10.1.34.2 10.0.4.4 17 32 80000001 0
Sum-Net 10.1.23.0 10.0.3.3 57 28 80000001 1
Sum-Net 10.1.25.0 10.0.3.3 57 28 80000001 2
Sum-Net 10.1.12.0 10.0.3.3 57 28 80000001 2
Sum-Net 10.0.3.3 10.0.3.3 57 28 80000001 0
Sum-Net 10.0.2.2 10.0.3.3 57 28 80000001 1
Sum-Net 10.0.5.5 10.0.3.3 57 28 80000001 2
NSSA 10.0.4.4 10.0.4.4 76 36 80000001 1
NSSA 10.1.34.0 10.0.4.4 76 36 80000002 1
NSSA 0.0.0.0 10.0.3.3 57 36 80000001 1
<R4>display ospf lsdb
OSPF Process 1 with Router ID 10.0.4.4
Link State Database
Area: 0.0.0.1
Type LinkState ID AdvRouter Age Len Sequence Metric
Router 10.0.3.3 10.0.3.3 73 36 80000004 1
Router 10.0.4.4 10.0.4.4 72 36 80000005 1
Network 10.1.34.2 10.0.4.4 73 32 80000001 0
Sum-Net 10.1.23.0 10.0.3.3 113 28 80000001 1
Sum-Net 10.1.25.0 10.0.3.3 113 28 80000001 2
Sum-Net 10.1.12.0 10.0.3.3 113 28 80000001 2
Sum-Net 10.0.3.3 10.0.3.3 113 28 80000001 0
Sum-Net 10.0.2.2 10.0.3.3 113 28 80000001 1
Sum-Net 10.0.5.5 10.0.3.3 113 28 80000001 2
NSSA 10.0.4.4 10.0.4.4 132 36 80000001 1
NSSA 10.1.34.0 10.0.4.4 132 36 80000002 1
NSSA 0.0.0.0 10.0.3.3 113 36 80000001 1 在NSSA区域内不允许其他区域的外部路由进入，但是NSSA区域可以引入外部路由，并且以Type-7 LSA通告给本区域。在ABR上会向区域内下发一条由Type-7描述的默认路由。
在R3上观察LSA
java
<R3>display ospf lsdb
OSPF Process 1 with Router ID 10.0.3.3
Link State Database
Area: 0.0.0.0
Type LinkState ID AdvRouter Age Len Sequence Metric
Router 10.0.3.3 10.0.3.3 676 60 80000005 0
Router 10.0.2.2 10.0.2.2 129 60 80000006 0
Sum-Net 10.1.25.0 10.0.2.2 1075 28 80000002 1
Sum-Net 10.1.34.0 10.0.3.3 676 28 80000002 1
Sum-Net 10.1.12.0 10.0.2.2 245 28 80000002 1
Sum-Net 10.0.5.5 10.0.2.2 1055 28 80000001 1
Sum-Asbr 10.0.1.1 10.0.2.2 241 28 80000002 1
Area: 0.0.0.1
Type LinkState ID AdvRouter Age Len Sequence Metric
Router 10.0.3.3 10.0.3.3 636 36 80000004 1
Router 10.0.4.4 10.0.4.4 637 36 80000005 1
Network 10.1.34.2 10.0.4.4 638 32 80000001 0
Sum-Net 10.1.23.0 10.0.3.3 676 28 80000001 1
Sum-Net 10.1.25.0 10.0.3.3 676 28 80000001 2
Sum-Net 10.1.12.0 10.0.3.3 676 28 80000001 2
Sum-Net 10.0.3.3 10.0.3.3 676 28 80000001 0
Sum-Net 10.0.2.2 10.0.3.3 676 28 80000001 1
Sum-Net 10.0.5.5 10.0.3.3 676 28 80000001 2
NSSA 0.0.0.0 10.0.3.3 676 36 80000001 1
NSSA 10.0.4.4 10.0.4.4 697 36 80000001 1
NSSA 10.1.34.0 10.0.4.4 697 36 80000002 1
AS External Database
Type LinkState ID AdvRouter Age Len Sequence Metric
External 10.0.4.4 10.0.3.3 636 36 80000001 1
External 10.0.4.4 10.0.4.4 1867 36 80000001 1
External 10.0.1.1 10.0.1.1 357 36 80000002 1
External 10.1.12.0 10.0.1.1 357 36 80000002 1
External 10.1.34.0 10.0.4.4 1867 36 80000001 1 在R3上将Type-7类LSA转换为Type-5类LSA通告给其他区域。
在R3上观察OSPF摘要信息，可以看到此时R3的身份为AREA AS NSSA，分别代表路由器为ABR、ASBR以及存在接口属于NSSA。
java
<R3>display ospf brief
OSPF Process 1 with Router ID 10.0.3.3
OSPF Protocol Information
RouterID: 10.0.3.3 Border Router: AREA AS NSSA
Multi-VPN-Instance is not enabled
Global DS-TE Mode: Non-Standard IETF Mode
Graceful-restart capability: disabled
Helper support capability : not configured
Applications Supported: MPLS Traffic-Engineering
Spf-schedule-interval: max 10000ms, start 500ms, hold 1000ms
Default ASE parameters: Metric: 1 Tag: 1 Type: 2
Route Preference: 10
ASE Route Preference: 150
SPF Computation Count: 15
RFC 1583 Compatible
Retransmission limitation is disabled
Area Count: 2 Nssa Area Count: 1
ExChange/Loading Neighbors: 0
Process total up interface count: 3
Process valid up interface count: 2
Area: 0.0.0.0 (MPLS TE not enabled)
Authtype: None Area flag: Normal
SPF scheduled Count: 15
ExChange/Loading Neighbors: 0
Router ID conflict state: Normal
Area interface up count: 2
Interface: 10.0.3.3 (LoopBack0)
Cost: 0 State: P-2-P Type: P2P MTU: 1500
Timers: Hello 10 , Dead 40 , Poll 120 , Retransmit 5 , Transmit Delay 1
Interface: 10.1.23.2 (GigabitEthernet0/0/0) --> 10.1.23.1