1.1.1实验介绍1.1.1.1学习目标实现OSPF Stub区域的配置实现OSPF NSSA区域的配置描述Type-7 LSA的内容描述Type-7 LSA与Type-5 LSA之间的转换过程1.1.1.2实验组网介绍图1-4OSPF Stub区域与NSSA区域设备互联方式及IP地址规划如图所示OSPF区域规划如下R1与R3的互联接口、R1的Loopback0接口属于OSPF区域2。R3与R4的互联接口以及它们的Loopback0接口属于OSPF区域0。R4与R5的互联接口属于OSPF区域1R5的Loopback0接口不属于任何区域。R2与R3的互联接口属于OSPF区域3R2的Loopback0接口不属于任何区域。1.1.1.3实验背景你是公司的网络管理员。现在公司的网络中有五台AR路由器其中R2、R3和R4在公司总部。R5在公司分部R1在公司的另外一个分部。为了减轻分部设备的压力你设置区域1为NSSA区域、区域2为Stub区域。同时为了明确设备的Router ID你配置设备使用固定的地址作为Router ID。1.1.2实验任务1.1.2.1任务思路设备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R2、R5上将外部路由引入到OSPF中。配置区域2为Stub区域观察区域2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。1.1.2.2任务步骤步骤 1互联接口、环回口IP地址配置#设备命名略#关闭本实验中未使用的接口略#配置R1的GE0/0/1、Loopback0接口IP地址[R1]interface LoopBack0[R1-LoopBack0] ip address 10.0.1.1 255.255.255.0[R1-LoopBack0] quit[R1]interface GigabitEthernet0/0/1[R1-GigabitEthernet0/0/1] ip address 10.0.13.1 255.255.255.0[R1-GigabitEthernet0/0/1] quit#配置R2的GE0/0/2、Loopback0接口IP地址[R2]interface GigabitEthernet0/0/2[R2-GigabitEthernet0/0/2] ip address 10.0.23.2 255.255.255.0[R2-GigabitEthernet0/0/2] quit[R2]interface LoopBack0[R2-LoopBack0] ip address 10.0.2.2 255.255.255.0[R2-LoopBack0] quit#配置R3的GE0/0/1、GE0/0/2、GE0/0/3、Loopback0接口IP地址[R3]interface LoopBack0[R3-LoopBack0] ip address 10.0.3.3 255.255.255.0[R3-LoopBack0] quit[R3]interface GigabitEthernet0/0/1[R3-GigabitEthernet0/0/1] ip address 10.0.13.3 255.255.255.0[R3-GigabitEthernet0/0/1] quit[R3]interface GigabitEthernet0/0/2[R3-GigabitEthernet0/0/2] ip address 10.0.34.3 255.255.255.0[R3-GigabitEthernet0/0/2] quit[R3]interface GigabitEthernet0/0/3[R3-GigabitEthernet0/0/3] ip address 10.0.23.3 255.255.255.0[R3-GigabitEthernet0/0/3] quit#配置R4的GE0/0/2、GE0/0/3、Loopback0接口IP地址[R4]interface LoopBack0[R4-LoopBack0] ip address 10.0.4.4 255.255.255.0[R4-LoopBack0] quit[R4]interface GigabitEthernet0/0/2[R4-GigabitEthernet0/0/2] ip address 10.0.45.4 255.255.255.0[R4-GigabitEthernet0/0/2] quit[R4]interface GigabitEthernet0/0/3[R4-GigabitEthernet0/0/3] ip address 10.0.34.4 255.255.255.0[R4-GigabitEthernet0/0/3] quit#配置R5的GE0/0/3、Loopback0接口IP地址[R5]interface LoopBack0[R5-LoopBack0] ip address 10.0.5.5 255.255.255.0[R5-LoopBack0] quit[R5]interface GigabitEthernet0/0/3[R5-GigabitEthernet0/0/3] ip address 10.0.45.5 255.255.255.0[R5-GigabitEthernet0/0/3] quit#在R3、R5上检查互联地址连通性R3ping -c 1 10.0.13.1PING 10.0.13.1: 56 data bytes, press CTRL_C to breakReply from 10.0.13.1: bytes56 Sequence1 ttl255 time40 ms--- 10.0.13.1 ping statistics ---1 packet(s) transmitted1 packet(s) received0.00% packet lossround-trip min/avg/max 40/40/40 msR3ping -c 1 10.0.23.2PING 10.0.23.2: 56 data bytes, press CTRL_C to breakReply from 10.0.23.2: bytes56 Sequence1 ttl255 time60 ms--- 10.0.23.2 ping statistics ---1 packet(s) transmitted1 packet(s) received0.00% packet lossround-trip min/avg/max 60/60/60 msR3ping -c 1 10.0.34.4PING 10.0.34.4: 56 data bytes, press CTRL_C to breakReply from 10.0.34.4: bytes56 Sequence1 ttl255 time60 ms--- 10.0.34.4 ping statistics ---1 packet(s) transmitted1 packet(s) received0.00% packet lossround-trip min/avg/max 60/60/60 msR5ping -c 1 10.0.45.4PING 10.0.45.4: 56 data bytes, press CTRL_C to breakReply from 10.0.45.4: bytes56 Sequence1 ttl255 time70 ms--- 10.0.45.4 ping statistics ---1 packet(s) transmitted1 packet(s) received0.00% packet lossround-trip min/avg/max 70/70/70 ms步骤 2配置多区域OSPF按照规划配置OSPF手动指定Loopback0接口地址为OSPF Router ID修改Loopback0接口的网络类型为Broadcast。#配置R1[R1] ospf 1 router-id 10.0.1.1[R1-ospf-1] area 0.0.0.2[R1-ospf-1-area-0.0.0.2] network 10.0.1.1 0.0.0.0[R1-ospf-1-area-0.0.0.2] network 10.0.13.1 0.0.0.0[R1-ospf-1-area-0.0.0.2] quit[R1-ospf-1] quit[R1] interface LoopBack0[R1-LoopBack0] ospf network-type broadcast#配置R2[R2] ospf 1 router-id 10.0.2.2[R2-ospf-1] area 0.0.0.3[R2-ospf-1-area-0.0.0.3] network 10.0.23.2 0.0.0.0[R2-ospf-1-area-0.0.0.3] quit[R2-ospf-1] quit[R2] interface LoopBack0[R2-LoopBack0] ospf network-type broadcast#配置R3[R3] ospf 1 router-id 10.0.3.3[R3-ospf-1] area 0.0.0.0[R3-ospf-1-area-0.0.0.0] network 10.0.3.3 0.0.0.0[R3-ospf-1-area-0.0.0.0] network 10.0.34.3 0.0.0.0[R3-ospf-1-area-0.0.0.0] area 0.0.0.2[R3-ospf-1-area-0.0.0.2] network 10.0.13.3 0.0.0.0[R3-ospf-1-area-0.0.0.2] area 0.0.0.3[R3-ospf-1-area-0.0.0.3] network 10.0.23.3 0.0.0.0[R3-ospf-1-area-0.0.0.3] quit[R3-ospf-1] quit[R3] interface LoopBack0[R3-LoopBack0] ospf network-type broadcast#配置R4[R4] ospf 1 router-id 10.0.4.4[R4-ospf-1] area 0.0.0.0[R4-ospf-1-area-0.0.0.0] network 10.0.4.4 0.0.0.0[R4-ospf-1-area-0.0.0.0] network 10.0.34.4 0.0.0.0[R4-ospf-1-area-0.0.0.0] area 0.0.0.1[R4-ospf-1-area-0.0.0.1] network 10.0.45.4 0.0.0.0[R4-ospf-1-area-0.0.0.1] quit[R4-ospf-1] quit[R4] interface LoopBack0[R4-LoopBack0] ospf network-type broadcast#配置R5[R5] ospf 1 router-id 10.0.5.5[R5-ospf-1] area 1[R5-ospf-1-area-0.0.0.1] network 10.0.45.5 0.0.0.0[R5-ospf-1-area-0.0.0.1] quit[R5-ospf-1] quit[R5] interface LoopBack0[R5-LoopBack0] ospf network-type broadcast步骤 3检查OSPF多区域配置#在R3上检查OSPF邻居的概要信息R3display ospf peer briefOSPF Process 1 with Router ID 10.0.3.3Peer Statistic Information----------------------------------------------------------------------------Area Id Interface Neighbor id State0.0.0.0 GigabitEthernet0/0/2 10.0.4.4 Full0.0.0.2 GigabitEthernet0/0/1 10.0.1.1 Full0.0.0.3 GigabitEthernet0/0/3 10.0.2.2 Full----------------------------------------------------------------------------#在R5上检查OSPF邻居的概要信息R5display ospf peer briefOSPF Process 1 with Router ID 10.0.5.5Peer Statistic Information----------------------------------------------------------------------------Area Id Interface Neighbor id State0.0.0.1 GigabitEthernet0/0/3 10.0.4.4 Full----------------------------------------------------------------------------从输出信息可以判断出所有设备之间的OSPF邻居关系状态正常。#在R3上查看OSPF路由表R3display ospf routingOSPF Process 1 with Router ID 10.0.3.3Routing TablesRouting for NetworkDestination Cost Type NextHop AdvRouter Area10.0.3.0/24 0 Stub 10.0.3.3 10.0.3.3 0.0.0.010.0.13.0/24 1 Transit 10.0.13.3 10.0.3.3 0.0.0.210.0.23.0/24 1 Transit 10.0.23.3 10.0.3.3 0.0.0.310.0.34.0/24 1 Transit 10.0.34.3 10.0.3.3 0.0.0.010.0.1.0/24 1 Stub 10.0.13.1 10.0.1.1 0.0.0.210.0.4.0/24 1 Stub 10.0.34.4 10.0.4.4 0.0.0.010.0.45.0/24 2 Inter-area 10.0.34.4 10.0.4.4 0.0.0.0Total Nets: 7Intra Area: 6 Inter Area: 1 ASE: 0 NSSA: 0除了未激活OSPF的R2 Loopback0接口、R5 Loopback0接口R3已经学习到其余接口路由。步骤 4配置将外部路由引入到OSPF中#将R5的Loopback0接口路由引入到OSPF中[R5] ospf 1[R5-ospf-1] import-route direct#在R2上配置缺省路由且指定出接口为 Loopback0接口并将该缺省路由引入到OSPF中外部路由类型设置为1Cost值设置为20不携带always参数[R2] ip route-static 0.0.0.0 0.0.0.0 LoopBack 0[R2] ospf 1[R2-ospf-1] default-route-advertise type 1 cost 20#在R3上查看引入的外部路由并测试其连通性R3display ospf routing 0.0.0.0OSPF Process 1 with Router ID 10.0.3.3Destination :0.0.0.0/0AdverRouter : 10.0.2.2 Tag : 1Cost : 21 Type : Type1NextHop : 10.0.23.2 Interface : GigabitEthernet0/0/3Priority : Low Age : 00h01m15sR3display ospf routing 10.0.5.5OSPF Process 1 with Router ID 10.0.3.3Destination :10.0.5.0/24AdverRouter : 10.0.5.5 Tag : 1Cost : 1 Type : Type2NextHop : 10.0.34.4 Interface : GigabitEthernet0/0/2Priority : Low Age : 00h05m20sR3ping -c 1 10.0.5.5PING 10.0.5.5: 56 data bytes, press CTRL_C to breakReply from 10.0.5.5: bytes56 Sequence1 ttl254 time50 ms--- 10.0.5.5 ping statistics ---1 packet(s) transmitted1 packet(s) received0.00% packet lossround-trip min/avg/max 50/50/50 msR3ping -c 1 10.0.2.2PING 10.0.2.2: 56 data bytes, press CTRL_C to breakReply from 10.0.2.2: bytes56 Sequence1 ttl255 time50 ms--- 10.0.2.2 ping statistics ---1 packet(s) transmitted1 packet(s) received0.00% packet lossround-trip min/avg/max 50/50/50 ms步骤 5配置区域2为Stub区域#在R1上查看OSPF路由表R1display ospf routingOSPF Process 1 with Router ID 10.0.1.1Routing TablesRouting for NetworkDestination Cost Type NextHop AdvRouter Area10.0.1.0/24 0 Stub 10.0.1.1 10.0.1.1 0.0.0.210.0.13.0/24 1 Transit 10.0.13.1 10.0.1.1 0.0.0.210.0.3.0/24 1 Inter-area 10.0.13.3 10.0.3.3 0.0.0.210.0.4.0/24 2 Inter-area 10.0.13.3 10.0.3.3 0.0.0.210.0.23.0/24 2 Inter-area 10.0.13.3 10.0.3.3 0.0.0.210.0.34.0/24 2 Inter-area 10.0.13.3 10.0.3.3 0.0.0.210.0.45.0/24 3 Inter-area 10.0.13.3 10.0.3.3 0.0.0.2Routing for ASEsDestination Cost Type Tag NextHop AdvRouter0.0.0.0/0 22 Type1 1 10.0.13.3 10.0.2.210.0.5.0/24 1 Type2 1 10.0.13.3 10.0.5.5Total Nets: 9Intra Area: 2 Inter Area: 5 ASE: 2 NSSA: 0此时默认路由为OSPF外部路由。#在R1、R3上配置区域2为Stub区域[R1] ospf 1[R1-ospf-1] area 0.0.0.2[R1-ospf-1-area-0.0.0.2] stub[R3] ospf 1[R3-ospf-1] area 0.0.0.2[R3-ospf-1-area-0.0.0.2] stub#再次在R1上查看OSPF路由表R1display ospf routingOSPF Process 1 with Router ID 10.0.1.1Routing TablesRouting for NetworkDestination Cost Type NextHop AdvRouter Area10.0.1.0/24 0 Stub 10.0.1.1 10.0.1.1 0.0.0.210.0.13.0/24 1 Transit 10.0.13.1 10.0.1.1 0.0.0.20.0.0.0/0 2 Inter-area10.0.13.3 10.0.3.3 0.0.0.210.0.3.0/24 1 Inter-area 10.0.13.3 10.0.3.3 0.0.0.210.0.4.0/24 2 Inter-area 10.0.13.3 10.0.3.3 0.0.0.210.0.23.0/24 2 Inter-area 10.0.13.3 10.0.3.3 0.0.0.210.0.34.0/24 2 Inter-area 10.0.13.3 10.0.3.3 0.0.0.210.0.45.0/24 3 Inter-area 10.0.13.3 10.0.3.3 0.0.0.2Total Nets: 8Intra Area: 2 Inter Area: 6ASE: 0NSSA: 0此时R1上不存在OSPF外部路由原本的OSPF外部路由条目0.0.0.0/0、10.0.5.0/24被一条缺省的OSPF区域间路由所取代。#查看R1的OSPF LSDBR1display ospf lsdbOSPF Process 1 with Router ID 10.0.1.1Link State DatabaseArea: 0.0.0.2Type LinkState ID AdvRouter Age Len Sequence MetricRouter 10.0.3.3 10.0.3.3 628 36 80000004 1Router 10.0.1.1 10.0.1.1 619 48 80000007 0Network 10.0.13.1 10.0.1.1 619 32 80000002 0Sum-Net0.0.0.010.0.3.363128800000011Sum-Net 10.0.34.0 10.0.3.3 631 28 80000001 1Sum-Net 10.0.3.0 10.0.3.3 631 28 80000001 0Sum-Net 10.0.4.0 10.0.3.3 631 28 80000001 1Sum-Net 10.0.45.0 10.0.3.3 631 28 80000001 2Sum-Net 10.0.23.0 10.0.3.3 631 28 80000001 1R1上此时不存在Type-4 LSA、Type-5 LSA去往OSPF域外通过ABR生成的Type-3 LSA所携带的缺省路由实现。同时此时前往其他区域的Type-3 LSA依旧存在。以上验证了将一个区域配置为Stub区域以后ABR会阻断Type-4 LSA、Type-5 LSA向该区域发送并通过Type-3 LSA向该区域内泛洪一条默认路由指向ABR自身。#在R3上配置区域2为Totally Stub区域[R3] ospf 1[R3-ospf-1] area 0.0.0.2[R3-ospf-1-area-0.0.0.2] stub no-summary#再次在R1上查看OSPF路由表、LSDBR1display ospf routingOSPF Process 1 with Router ID 10.0.1.1Routing TablesRouting for NetworkDestination Cost Type NextHop AdvRouter Area10.0.1.0/24 0 Stub 10.0.1.1 10.0.1.1 0.0.0.210.0.13.0/24 1 Transit 10.0.13.1 10.0.1.1 0.0.0.20.0.0.0/0 2 Inter-area 10.0.13.3 10.0.3.3 0.0.0.2Total Nets: 3Intra Area: 2 Inter Area: 1 ASE: 0 NSSA: 0R1display ospf lsdbOSPF Process 1 with Router ID 10.0.1.1Link State DatabaseArea: 0.0.0.2Type LinkState ID AdvRouter Age Len Sequence MetricRouter 10.0.3.3 10.0.3.3 125 36 80000005 1Router 10.0.1.1 10.0.1.1 121 48 8000000C 0Network 10.0.13.1 10.0.1.1 121 32 80000002 0Sum-Net 0.0.0.0 10.0.3.3 961 28 80000001 1此时原本多条OSPF区域间路由只剩一条0.0.0.0/0缺省路由LSDB中Type-3 LSA只剩一条0.0.0.0。这就验证了Totally Stub区域中ABR会阻断了Type-3 LSA、Type-4 LSA、Type-5 LSA并生成一条Type-3 LSA通告一条指向自身的缺省路由。步骤 6配置区域1为NSSA区域#查看R4的OSPF路由表R4display ospf routingOSPF Process 1 with Router ID 10.0.4.4Routing TablesRouting for NetworkDestination Cost Type NextHop AdvRouter Area10.0.4.0/24 0 Stub 10.0.4.4 10.0.4.4 0.0.0.010.0.34.0/24 1 Transit 10.0.34.4 10.0.4.4 0.0.0.010.0.45.0/24 1 Transit 10.0.45.4 10.0.4.4 0.0.0.110.0.1.0/24 2 Inter-area 10.0.34.3 10.0.3.3 0.0.0.010.0.3.0/24 1 Stub 10.0.34.3 10.0.3.3 0.0.0.010.0.13.0/24 2 Inter-area 10.0.34.3 10.0.3.3 0.0.0.010.0.23.0/24 2 Inter-area 10.0.34.3 10.0.3.3 0.0.0.0Routing for ASEsDestination Cost Type Tag NextHop AdvRouter0.0.0.0/0 22 Type1 1 10.0.34.3 10.0.2.210.0.5.0/24 1 Type2 1 10.0.45.5 10.0.5.5Total Nets: 9Intra Area: 4 Inter Area: 3 ASE: 2 NSSA: 0此时R5存在一条由Type-5 LSA描述的外部路由10.0.5.0/24。#查看R5的OSPF路由表R5display ospf routingOSPF Process 1 with Router ID 10.0.5.5Routing TablesRouting for NetworkDestination Cost Type NextHop AdvRouter Area10.0.45.0/24 1 Transit 10.0.45.5 10.0.5.5 0.0.0.110.0.1.0/24 3 Inter-area 10.0.45.4 10.0.4.4 0.0.0.110.0.3.0/24 2 Inter-area 10.0.45.4 10.0.4.4 0.0.0.110.0.4.0/24 1 Inter-area 10.0.45.4 10.0.4.4 0.0.0.110.0.13.0/24 3 Inter-area 10.0.45.4 10.0.4.4 0.0.0.110.0.23.0/24 3 Inter-area 10.0.45.4 10.0.4.4 0.0.0.110.0.34.0/24 2 Inter-area 10.0.45.4 10.0.4.4 0.0.0.1Routing for ASEsDestination Cost Type Tag NextHop AdvRouter0.0.0.0/0 23 Type1 1 10.0.45.4 10.0.2.2Total Nets: 8Intra Area: 1 Inter Area: 6 ASE: 1 NSSA: 0在R5的OSPF路由表中出现的缺省路由是由Type-5 LSA所描述的该LSA由R2产生。#在R4、R5上配置区域1为NSSA区域[R4]ospf 1[R4-ospf-1] area 0.0.0.1[R4-ospf-1-area-0.0.0.1] nssa[R5]ospf 1[R5-ospf-1] area 0.0.0.1[R5-ospf-1-area-0.0.0.1] nssa#再次查看R5的OSPF路由表R5display ospf routingOSPF Process 1 with Router ID 10.0.5.5Routing TablesRouting for NetworkDestination Cost Type NextHop AdvRouter Area10.0.45.0/24 1 Transit 10.0.45.5 10.0.5.5 0.0.0.110.0.1.0/24 3 Inter-area 10.0.45.4 10.0.4.4 0.0.0.110.0.3.0/24 2 Inter-area 10.0.45.4 10.0.4.4 0.0.0.110.0.4.0/24 1 Inter-area 10.0.45.4 10.0.4.4 0.0.0.110.0.13.0/24 3 Inter-area 10.0.45.4 10.0.4.4 0.0.0.110.0.23.0/24 3 Inter-area 10.0.45.4 10.0.4.4 0.0.0.110.0.34.0/24 2 Inter-area 10.0.45.4 10.0.4.4 0.0.0.1Routing forNSSAsDestination Cost Type Tag NextHop AdvRouter0.0.0.0/01 Type2 1 10.0.45.410.0.4.4Total Nets: 8Intra Area: 1 Inter Area: 6 ASE: 0 NSSA: 1此时不存在由R2发布的缺省路由存在一条由R4发布的Type-7 LSA描述的OSPF缺省路由。#查看R5 LSDBR5display ospf lsdbOSPF Process 1 with Router ID 10.0.5.5Link State DatabaseArea: 0.0.0.1Type LinkState ID AdvRouter Age Len Sequence MetricRouter 10.0.5.5 10.0.5.5 100 36 80000005 1Router 10.0.4.4 10.0.4.4 105 36 80000005 1Network 10.0.45.5 10.0.5.5 100 32 80000002 0Sum-Net 10.0.34.0 10.0.4.4 151 28 80000001 1Sum-Net 10.0.13.0 10.0.4.4 151 28 80000001 2Sum-Net 10.0.3.0 10.0.4.4 151 28 80000001 1Sum-Net 10.0.1.0 10.0.4.4 151 28 80000001 2Sum-Net 10.0.4.0 10.0.4.4 151 28 80000001 0Sum-Net 10.0.23.0 10.0.4.4 151 28 80000001 2NSSA10.0.5.010.0.5.514336800000011NSSA10.0.45.010.0.5.514336800000021NSSA0.0.0.010.0.4.415136800000011此时不存在Type-4 LSA、Type-5 LSA外部路由以Type-7 LSANSSA的形式存在。#查看R4的OSPF路由表[R4]display ospf routingOSPF Process 1 with Router ID 10.0.4.4Routing TablesRouting for NetworkDestination Cost Type NextHop AdvRouter Area10.0.4.0/24 0 Stub 10.0.4.4 10.0.4.4 0.0.0.010.0.34.0/24 1 Transit 10.0.34.4 10.0.4.4 0.0.0.010.0.45.0/24 1 Transit 10.0.45.4 10.0.4.4 0.0.0.110.0.1.0/24 2 Inter-area 10.0.34.3 10.0.3.3 0.0.0.010.0.3.0/24 1 Stub 10.0.34.3 10.0.3.3 0.0.0.010.0.13.0/24 2 Inter-area 10.0.34.3 10.0.3.3 0.0.0.010.0.23.0/24 2 Inter-area 10.0.34.3 10.0.3.3 0.0.0.0Routing for ASEsDestination Cost Type Tag NextHop AdvRouter0.0.0.0/0 22 Type1 1 10.0.34.3 10.0.2.2Routing for NSSAsDestination Cost Type Tag NextHop AdvRouter10.0.5.0/24 1 Type2 1 10.0.45.5 10.0.5.5Total Nets: 9Intra Area: 4 Inter Area: 3 ASE: 1 NSSA: 1R5所引入的外部路由10.0.5.0/24由Type-7 LSA所描述。以上验证了NSSA区域阻断了外部的Type-4 LSA、Type-5 LSA进入并且ABR会向区域内下发一条由Type-7 LSA描述的默认路由。ASBR向NSSA区域内下发Type-7 LSA描述本区域中引入的外部路由。步骤 7观察NSSA对OSPF产生的影响#在R4上查看OSPF概要信息R4display ospf briefOSPF Process 1 with Router ID 10.0.4.4OSPF Protocol InformationRouterID: 10.0.4.4Border Router: AREA AS NSSAMulti-VPN-Instance is not enabledGlobal DS-TE Mode: Non-Standard IETF ModeSpf-schedule-interval: max 10000ms, start 500ms, hold 1000msDefault ASE parameters: Metric: 1 Tag: 1 Type: 2Route Preference: 10ASE Route Preference: 150SPF Computation Count: 22RFC 1583 CompatibleRetransmission limitation is disabledArea Count: 2 Nssa Area Count: 1ExChange/Loading Neighbors: 0Area: 0.0.0.0 (MPLS TE not enabled)Authtype: None Area flag: NormalSPF scheduled Count: 22ExChange/Loading Neighbors: 0Router ID conflict state: NormalInterface: 10.0.4.4 (LoopBack0)Cost: 0 State: DR Type: Broadcast MTU: 1500Priority: 1Designated Router: 10.0.4.4Backup Designated Router: 0.0.0.0Timers: Hello 10 , Dead 40 , Poll 120 , Retransmit 5 , Transmit Delay 1Interface: 10.0.34.4 (GigabitEthernet0/0/3)Cost: 1 State: BDR Type: Broadcast MTU: 1500Priority: 1Designated Router: 10.0.34.3Backup Designated Router: 10.0.34.4Timers: Hello 10 , Dead 40 , Poll 120 , Retransmit 5 , Transmit Delay 1Area: 0.0.0.1 (MPLS TE not enabled)Authtype: None Area flag: NSSASPF scheduled Count: 6ExChange/Loading Neighbors: 0NSSA Translator State: ElectedRouter ID conflict state: NormalInterface: 10.0.45.4 (GigabitEthernet0/0/2)Cost: 1 State: BDR Type: Broadcast MTU: 1500Priority: 1Designated Router: 10.0.45.5Backup Designated Router: 10.0.45.4Timers: Hello 10 , Dead 40 , Poll 120 , Retransmit 5 , Transmit Delay 1在Border Router字段可以看到R4此时的身份为AREA AS NSSA分别代表该路由器为ABR、ASBR以及存在接口属于NSSA区域。#在R4上观察Type-7 LSA向Type-5 LSA转换的过程以10.0.5.0/24为例观察路由信息的传递过程R4display ospf lsdb nssa 10.0.5.0OSPF Process 1 with Router ID 10.0.4.4Area: 0.0.0.0Link State DatabaseArea: 0.0.0.1Link State DatabaseType : NSSALs id : 10.0.5.0Adv rtr : 10.0.5.5Ls age : 587Len : 36Options : NPseq# : 80000001chksum : 0x3336Net mask : 255.255.255.0TOS 0 Metric: 1E type : 2Forwarding Address : 10.0.45.5Tag : 1Priority : Low首先查看描述10.0.5.0/24的Type-7 LSA其options字段为NP表示该LSA可以被ABR转化成一条Type-5 LSA。#在R4上查看生成的用于描述10.0.5.0/24的Type-5 LSAR4display ospf lsdb ase 10.0.5.0OSPF Process 1 with Router ID 10.0.4.4Link State DatabaseType : ExternalLs id : 10.0.5.0Adv rtr : 10.0.4.4Ls age : 753Len : 36Options : Eseq# : 80000001chksum : 0xb6bcNet mask : 255.255.255.0TOS 0 Metric: 1E type : 2Forwarding Address : 10.0.45.5Tag : 1Priority : Low可以看到与Type-7 LSA相比其Ls id、net mask、FA地址字段内容完全相同adv rtr字段值从10.0.5.5变为了10.0.4.4说明该Type-5 LSA由R4产生。1.1.3思考题在什么场景下适合使用NSSA区域1.1.4配置参考R1设备配置#sysname R1#interface GigabitEthernet0/0/1ip address 10.0.13.1 255.255.255.0#interface LoopBack0ip address 10.0.1.1 255.255.255.0ospf network-type broadcast#ospf 1 router-id 10.0.1.1area 0.0.0.2network 10.0.1.1 0.0.0.0network 10.0.13.1 0.0.0.0stub#R2设备配置#sysname R2#interface GigabitEthernet0/0/2ip address 10.0.23.2 255.255.255.0#interface LoopBack0ip address 10.0.2.2 255.255.255.0ospf network-type broadcast#ospf 1 router-id 10.0.2.2default-route-advertise cost 20 type 1area 0.0.0.3network 10.0.23.2 0.0.0.0#ip route-static 0.0.0.0 0.0.0.0 LoopBack0#R3设备配置#sysname R3#interface GigabitEthernet0/0/1ip address 10.0.13.3 255.255.255.0#interface GigabitEthernet0/0/2ip address 10.0.34.3 255.255.255.0#interface GigabitEthernet0/0/3ip address 10.0.23.3 255.255.255.0#interface LoopBack0ip address 10.0.3.3 255.255.255.0ospf network-type broadcast#ospf 1 router-id 10.0.3.3area 0.0.0.0network 10.0.3.3 0.0.0.0network 10.0.34.3 0.0.0.0area 0.0.0.2network 10.0.13.3 0.0.0.0stub no-summaryarea 0.0.0.3network 10.0.23.3 0.0.0.0#R4设备配置#sysname R4#interface GigabitEthernet0/0/2ip address 10.0.45.4 255.255.255.0#interface GigabitEthernet0/0/3ip address 10.0.34.4 255.255.255.0#interface LoopBack0ip address 10.0.4.4 255.255.255.0ospf network-type broadcast#ospf 1 router-id 10.0.4.4area 0.0.0.0network 10.0.4.4 0.0.0.0network 10.0.34.4 0.0.0.0area 0.0.0.1network 10.0.45.4 0.0.0.0nssa#R5设备配置#sysname R5#interface GigabitEthernet0/0/3ip address 10.0.45.5 255.255.255.0#interface LoopBack0ip address 10.0.5.5 255.255.255.0ospf network-type broadcast#ospf 1 router-id 10.0.5.5import-route directarea 0.0.0.1network 10.0.45.5 0.0.0.0nssa# HCIP-Datacom实验（OSPF Stub区域与NSSA区域）
1.1.1实验介绍1.1.1.1学习目标实现OSPF Stub区域的配置实现OSPF NSSA区域的配置描述Type-7 LSA的内容描述Type-7 LSA与Type-5 LSA之间的转换过程1.1.1.2实验组网介绍图1-4OSPF Stub区域与NSSA区域设备互联方式及IP地址规划如图所示OSPF区域规划如下R1与R3的互联接口、R1的Loopback0接口属于OSPF区域2。R3与R4的互联接口以及它们的Loopback0接口属于OSPF区域0。R4与R5的互联接口属于OSPF区域1R5的Loopback0接口不属于任何区域。R2与R3的互联接口属于OSPF区域3R2的Loopback0接口不属于任何区域。1.1.1.3实验背景你是公司的网络管理员。现在公司的网络中有五台AR路由器其中R2、R3和R4在公司总部。R5在公司分部R1在公司的另外一个分部。为了减轻分部设备的压力你设置区域1为NSSA区域、区域2为Stub区域。同时为了明确设备的Router ID你配置设备使用固定的地址作为Router ID。1.1.2实验任务1.1.2.1任务思路设备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R2、R5上将外部路由引入到OSPF中。配置区域2为Stub区域观察区域2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。1.1.2.2任务步骤步骤 1互联接口、环回口IP地址配置#设备命名略#关闭本实验中未使用的接口略#配置R1的GE0/0/1、Loopback0接口IP地址[R1]interface LoopBack0[R1-LoopBack0] ip address 10.0.1.1 255.255.255.0[R1-LoopBack0] quit[R1]interface GigabitEthernet0/0/1[R1-GigabitEthernet0/0/1] ip address 10.0.13.1 255.255.255.0[R1-GigabitEthernet0/0/1] quit#配置R2的GE0/0/2、Loopback0接口IP地址[R2]interface GigabitEthernet0/0/2[R2-GigabitEthernet0/0/2] ip address 10.0.23.2 255.255.255.0[R2-GigabitEthernet0/0/2] quit[R2]interface LoopBack0[R2-LoopBack0] ip address 10.0.2.2 255.255.255.0[R2-LoopBack0] quit#配置R3的GE0/0/1、GE0/0/2、GE0/0/3、Loopback0接口IP地址[R3]interface LoopBack0[R3-LoopBack0] ip address 10.0.3.3 255.255.255.0[R3-LoopBack0] quit[R3]interface GigabitEthernet0/0/1[R3-GigabitEthernet0/0/1] ip address 10.0.13.3 255.255.255.0[R3-GigabitEthernet0/0/1] quit[R3]interface GigabitEthernet0/0/2[R3-GigabitEthernet0/0/2] ip address 10.0.34.3 255.255.255.0[R3-GigabitEthernet0/0/2] quit[R3]interface GigabitEthernet0/0/3[R3-GigabitEthernet0/0/3] ip address 10.0.23.3 255.255.255.0[R3-GigabitEthernet0/0/3] quit#配置R4的GE0/0/2、GE0/0/3、Loopback0接口IP地址[R4]interface LoopBack0[R4-LoopBack0] ip address 10.0.4.4 255.255.255.0[R4-LoopBack0] quit[R4]interface GigabitEthernet0/0/2[R4-GigabitEthernet0/0/2] ip address 10.0.45.4 255.255.255.0[R4-GigabitEthernet0/0/2] quit[R4]interface GigabitEthernet0/0/3[R4-GigabitEthernet0/0/3] ip address 10.0.34.4 255.255.255.0[R4-GigabitEthernet0/0/3] quit#配置R5的GE0/0/3、Loopback0接口IP地址[R5]interface LoopBack0[R5-LoopBack0] ip address 10.0.5.5 255.255.255.0[R5-LoopBack0] quit[R5]interface GigabitEthernet0/0/3[R5-GigabitEthernet0/0/3] ip address 10.0.45.5 255.255.255.0[R5-GigabitEthernet0/0/3] quit#在R3、R5上检查互联地址连通性R3ping -c 1 10.0.13.1PING 10.0.13.1: 56 data bytes, press CTRL_C to breakReply from 10.0.13.1: bytes56 Sequence1 ttl255 time40 ms--- 10.0.13.1 ping statistics ---1 packet(s) transmitted1 packet(s) received0.00% packet lossround-trip min/avg/max 40/40/40 msR3ping -c 1 10.0.23.2PING 10.0.23.2: 56 data bytes, press CTRL_C to breakReply from 10.0.23.2: bytes56 Sequence1 ttl255 time60 ms--- 10.0.23.2 ping statistics ---1 packet(s) transmitted1 packet(s) received0.00% packet lossround-trip min/avg/max 60/60/60 msR3ping -c 1 10.0.34.4PING 10.0.34.4: 56 data bytes, press CTRL_C to breakReply from 10.0.34.4: bytes56 Sequence1 ttl255 time60 ms--- 10.0.34.4 ping statistics ---1 packet(s) transmitted1 packet(s) received0.00% packet lossround-trip min/avg/max 60/60/60 msR5ping -c 1 10.0.45.4PING 10.0.45.4: 56 data bytes, press CTRL_C to breakReply from 10.0.45.4: bytes56 Sequence1 ttl255 time70 ms--- 10.0.45.4 ping statistics ---1 packet(s) transmitted1 packet(s) received0.00% packet lossround-trip min/avg/max 70/70/70 ms步骤 2配置多区域OSPF按照规划配置OSPF手动指定Loopback0接口地址为OSPF Router ID修改Loopback0接口的网络类型为Broadcast。#配置R1[R1] ospf 1 router-id 10.0.1.1[R1-ospf-1] area 0.0.0.2[R1-ospf-1-area-0.0.0.2] network 10.0.1.1 0.0.0.0[R1-ospf-1-area-0.0.0.2] network 10.0.13.1 0.0.0.0[R1-ospf-1-area-0.0.0.2] quit[R1-ospf-1] quit[R1] interface LoopBack0[R1-LoopBack0] ospf network-type broadcast#配置R2[R2] ospf 1 router-id 10.0.2.2[R2-ospf-1] area 0.0.0.3[R2-ospf-1-area-0.0.0.3] network 10.0.23.2 0.0.0.0[R2-ospf-1-area-0.0.0.3] quit[R2-ospf-1] quit[R2] interface LoopBack0[R2-LoopBack0] ospf network-type broadcast#配置R3[R3] ospf 1 router-id 10.0.3.3[R3-ospf-1] area 0.0.0.0[R3-ospf-1-area-0.0.0.0] network 10.0.3.3 0.0.0.0[R3-ospf-1-area-0.0.0.0] network 10.0.34.3 0.0.0.0[R3-ospf-1-area-0.0.0.0] area 0.0.0.2[R3-ospf-1-area-0.0.0.2] network 10.0.13.3 0.0.0.0[R3-ospf-1-area-0.0.0.2] area 0.0.0.3[R3-ospf-1-area-0.0.0.3] network 10.0.23.3 0.0.0.0[R3-ospf-1-area-0.0.0.3] quit[R3-ospf-1] quit[R3] interface LoopBack0[R3-LoopBack0] ospf network-type broadcast#配置R4[R4] ospf 1 router-id 10.0.4.4[R4-ospf-1] area 0.0.0.0[R4-ospf-1-area-0.0.0.0] network 10.0.4.4 0.0.0.0[R4-ospf-1-area-0.0.0.0] network 10.0.34.4 0.0.0.0[R4-ospf-1-area-0.0.0.0] area 0.0.0.1[R4-ospf-1-area-0.0.0.1] network 10.0.45.4 0.0.0.0[R4-ospf-1-area-0.0.0.1] quit[R4-ospf-1] quit[R4] interface LoopBack0[R4-LoopBack0] ospf network-type broadcast#配置R5[R5] ospf 1 router-id 10.0.5.5[R5-ospf-1] area 1[R5-ospf-1-area-0.0.0.1] network 10.0.45.5 0.0.0.0[R5-ospf-1-area-0.0.0.1] quit[R5-ospf-1] quit[R5] interface LoopBack0[R5-LoopBack0] ospf network-type broadcast步骤 3检查OSPF多区域配置#在R3上检查OSPF邻居的概要信息R3display ospf peer briefOSPF Process 1 with Router ID 10.0.3.3Peer Statistic Information----------------------------------------------------------------------------Area Id Interface Neighbor id State0.0.0.0 GigabitEthernet0/0/2 10.0.4.4 Full0.0.0.2 GigabitEthernet0/0/1 10.0.1.1 Full0.0.0.3 GigabitEthernet0/0/3 10.0.2.2 Full----------------------------------------------------------------------------#在R5上检查OSPF邻居的概要信息R5display ospf peer briefOSPF Process 1 with Router ID 10.0.5.5Peer Statistic Information----------------------------------------------------------------------------Area Id Interface Neighbor id State0.0.0.1 GigabitEthernet0/0/3 10.0.4.4 Full----------------------------------------------------------------------------从输出信息可以判断出所有设备之间的OSPF邻居关系状态正常。#在R3上查看OSPF路由表R3display ospf routingOSPF Process 1 with Router ID 10.0.3.3Routing TablesRouting for NetworkDestination Cost Type NextHop AdvRouter Area10.0.3.0/24 0 Stub 10.0.3.3 10.0.3.3 0.0.0.010.0.13.0/24 1 Transit 10.0.13.3 10.0.3.3 0.0.0.210.0.23.0/24 1 Transit 10.0.23.3 10.0.3.3 0.0.0.310.0.34.0/24 1 Transit 10.0.34.3 10.0.3.3 0.0.0.010.0.1.0/24 1 Stub 10.0.13.1 10.0.1.1 0.0.0.210.0.4.0/24 1 Stub 10.0.34.4 10.0.4.4 0.0.0.010.0.45.0/24 2 Inter-area 10.0.34.4 10.0.4.4 0.0.0.0Total Nets: 7Intra Area: 6 Inter Area: 1 ASE: 0 NSSA: 0除了未激活OSPF的R2 Loopback0接口、R5 Loopback0接口R3已经学习到其余接口路由。步骤 4配置将外部路由引入到OSPF中#将R5的Loopback0接口路由引入到OSPF中[R5] ospf 1[R5-ospf-1] import-route direct#在R2上配置缺省路由且指定出接口为 Loopback0接口并将该缺省路由引入到OSPF中外部路由类型设置为1Cost值设置为20不携带always参数[R2] ip route-static 0.0.0.0 0.0.0.0 LoopBack 0[R2] ospf 1[R2-ospf-1] default-route-advertise type 1 cost 20#在R3上查看引入的外部路由并测试其连通性R3display ospf routing 0.0.0.0OSPF Process 1 with Router ID 10.0.3.3Destination :0.0.0.0/0AdverRouter : 10.0.2.2 Tag : 1Cost : 21 Type : Type1NextHop : 10.0.23.2 Interface : GigabitEthernet0/0/3Priority : Low Age : 00h01m15sR3display ospf routing 10.0.5.5OSPF Process 1 with Router ID 10.0.3.3Destination :10.0.5.0/24AdverRouter : 10.0.5.5 Tag : 1Cost : 1 Type : Type2NextHop : 10.0.34.4 Interface : GigabitEthernet0/0/2Priority : Low Age : 00h05m20sR3ping -c 1 10.0.5.5PING 10.0.5.5: 56 data bytes, press CTRL_C to breakReply from 10.0.5.5: bytes56 Sequence1 ttl254 time50 ms--- 10.0.5.5 ping statistics ---1 packet(s) transmitted1 packet(s) received0.00% packet lossround-trip min/avg/max 50/50/50 msR3ping -c 1 10.0.2.2PING 10.0.2.2: 56 data bytes, press CTRL_C to breakReply from 10.0.2.2: bytes56 Sequence1 ttl255 time50 ms--- 10.0.2.2 ping statistics ---1 packet(s) transmitted1 packet(s) received0.00% packet lossround-trip min/avg/max 50/50/50 ms步骤 5配置区域2为Stub区域#在R1上查看OSPF路由表R1display ospf routingOSPF Process 1 with Router ID 10.0.1.1Routing TablesRouting for NetworkDestination Cost Type NextHop AdvRouter Area10.0.1.0/24 0 Stub 10.0.1.1 10.0.1.1 0.0.0.210.0.13.0/24 1 Transit 10.0.13.1 10.0.1.1 0.0.0.210.0.3.0/24 1 Inter-area 10.0.13.3 10.0.3.3 0.0.0.210.0.4.0/24 2 Inter-area 10.0.13.3 10.0.3.3 0.0.0.210.0.23.0/24 2 Inter-area 10.0.13.3 10.0.3.3 0.0.0.210.0.34.0/24 2 Inter-area 10.0.13.3 10.0.3.3 0.0.0.210.0.45.0/24 3 Inter-area 10.0.13.3 10.0.3.3 0.0.0.2Routing for ASEsDestination Cost Type Tag NextHop AdvRouter0.0.0.0/0 22 Type1 1 10.0.13.3 10.0.2.210.0.5.0/24 1 Type2 1 10.0.13.3 10.0.5.5Total Nets: 9Intra Area: 2 Inter Area: 5 ASE: 2 NSSA: 0此时默认路由为OSPF外部路由。#在R1、R3上配置区域2为Stub区域[R1] ospf 1[R1-ospf-1] area 0.0.0.2[R1-ospf-1-area-0.0.0.2] stub[R3] ospf 1[R3-ospf-1] area 0.0.0.2[R3-ospf-1-area-0.0.0.2] stub#再次在R1上查看OSPF路由表R1display ospf routingOSPF Process 1 with Router ID 10.0.1.1Routing TablesRouting for NetworkDestination Cost Type NextHop AdvRouter Area10.0.1.0/24 0 Stub 10.0.1.1 10.0.1.1 0.0.0.210.0.13.0/24 1 Transit 10.0.13.1 10.0.1.1 0.0.0.20.0.0.0/0 2 Inter-area10.0.13.3 10.0.3.3 0.0.0.210.0.3.0/24 1 Inter-area 10.0.13.3 10.0.3.3 0.0.0.210.0.4.0/24 2 Inter-area 10.0.13.3 10.0.3.3 0.0.0.210.0.23.0/24 2 Inter-area 10.0.13.3 10.0.3.3 0.0.0.210.0.34.0/24 2 Inter-area 10.0.13.3 10.0.3.3 0.0.0.210.0.45.0/24 3 Inter-area 10.0.13.3 10.0.3.3 0.0.0.2Total Nets: 8Intra Area: 2 Inter Area: 6ASE: 0NSSA: 0此时R1上不存在OSPF外部路由原本的OSPF外部路由条目0.0.0.0/0、10.0.5.0/24被一条缺省的OSPF区域间路由所取代。#查看R1的OSPF LSDBR1display ospf lsdbOSPF Process 1 with Router ID 10.0.1.1Link State DatabaseArea: 0.0.0.2Type LinkState ID AdvRouter Age Len Sequence MetricRouter 10.0.3.3 10.0.3.3 628 36 80000004 1Router 10.0.1.1 10.0.1.1 619 48 80000007 0Network 10.0.13.1 10.0.1.1 619 32 80000002 0Sum-Net0.0.0.010.0.3.363128800000011Sum-Net 10.0.34.0 10.0.3.3 631 28 80000001 1Sum-Net 10.0.3.0 10.0.3.3 631 28 80000001 0Sum-Net 10.0.4.0 10.0.3.3 631 28 80000001 1Sum-Net 10.0.45.0 10.0.3.3 631 28 80000001 2Sum-Net 10.0.23.0 10.0.3.3 631 28 80000001 1R1上此时不存在Type-4 LSA、Type-5 LSA去往OSPF域外通过ABR生成的Type-3 LSA所携带的缺省路由实现。同时此时前往其他区域的Type-3 LSA依旧存在。以上验证了将一个区域配置为Stub区域以后ABR会阻断Type-4 LSA、Type-5 LSA向该区域发送并通过Type-3 LSA向该区域内泛洪一条默认路由指向ABR自身。#在R3上配置区域2为Totally Stub区域[R3] ospf 1[R3-ospf-1] area 0.0.0.2[R3-ospf-1-area-0.0.0.2] stub no-summary#再次在R1上查看OSPF路由表、LSDBR1display ospf routingOSPF Process 1 with Router ID 10.0.1.1Routing TablesRouting for NetworkDestination Cost Type NextHop AdvRouter Area10.0.1.0/24 0 Stub 10.0.1.1 10.0.1.1 0.0.0.210.0.13.0/24 1 Transit 10.0.13.1 10.0.1.1 0.0.0.20.0.0.0/0 2 Inter-area 10.0.13.3 10.0.3.3 0.0.0.2Total Nets: 3Intra Area: 2 Inter Area: 1 ASE: 0 NSSA: 0R1display ospf lsdbOSPF Process 1 with Router ID 10.0.1.1Link State DatabaseArea: 0.0.0.2Type LinkState ID AdvRouter Age Len Sequence MetricRouter 10.0.3.3 10.0.3.3 125 36 80000005 1Router 10.0.1.1 10.0.1.1 121 48 8000000C 0Network 10.0.13.1 10.0.1.1 121 32 80000002 0Sum-Net 0.0.0.0 10.0.3.3 961 28 80000001 1此时原本多条OSPF区域间路由只剩一条0.0.0.0/0缺省路由LSDB中Type-3 LSA只剩一条0.0.0.0。这就验证了Totally Stub区域中ABR会阻断了Type-3 LSA、Type-4 LSA、Type-5 LSA并生成一条Type-3 LSA通告一条指向自身的缺省路由。步骤 6配置区域1为NSSA区域#查看R4的OSPF路由表R4display ospf routingOSPF Process 1 with Router ID 10.0.4.4Routing TablesRouting for NetworkDestination Cost Type NextHop AdvRouter Area10.0.4.0/24 0 Stub 10.0.4.4 10.0.4.4 0.0.0.010.0.34.0/24 1 Transit 10.0.34.4 10.0.4.4 0.0.0.010.0.45.0/24 1 Transit 10.0.45.4 10.0.4.4 0.0.0.110.0.1.0/24 2 Inter-area 10.0.34.3 10.0.3.3 0.0.0.010.0.3.0/24 1 Stub 10.0.34.3 10.0.3.3 0.0.0.010.0.13.0/24 2 Inter-area 10.0.34.3 10.0.3.3 0.0.0.010.0.23.0/24 2 Inter-area 10.0.34.3 10.0.3.3 0.0.0.0Routing for ASEsDestination Cost Type Tag NextHop AdvRouter0.0.0.0/0 22 Type1 1 10.0.34.3 10.0.2.210.0.5.0/24 1 Type2 1 10.0.45.5 10.0.5.5Total Nets: 9Intra Area: 4 Inter Area: 3 ASE: 2 NSSA: 0此时R5存在一条由Type-5 LSA描述的外部路由10.0.5.0/24。#查看R5的OSPF路由表R5display ospf routingOSPF Process 1 with Router ID 10.0.5.5Routing TablesRouting for NetworkDestination Cost Type NextHop AdvRouter Area10.0.45.0/24 1 Transit 10.0.45.5 10.0.5.5 0.0.0.110.0.1.0/24 3 Inter-area 10.0.45.4 10.0.4.4 0.0.0.110.0.3.0/24 2 Inter-area 10.0.45.4 10.0.4.4 0.0.0.110.0.4.0/24 1 Inter-area 10.0.45.4 10.0.4.4 0.0.0.110.0.13.0/24 3 Inter-area 10.0.45.4 10.0.4.4 0.0.0.110.0.23.0/24 3 Inter-area 10.0.45.4 10.0.4.4 0.0.0.110.0.34.0/24 2 Inter-area 10.0.45.4 10.0.4.4 0.0.0.1Routing for ASEsDestination Cost Type Tag NextHop AdvRouter0.0.0.0/0 23 Type1 1 10.0.45.4 10.0.2.2Total Nets: 8Intra Area: 1 Inter Area: 6 ASE: 1 NSSA: 0在R5的OSPF路由表中出现的缺省路由是由Type-5 LSA所描述的该LSA由R2产生。#在R4、R5上配置区域1为NSSA区域[R4]ospf 1[R4-ospf-1] area 0.0.0.1[R4-ospf-1-area-0.0.0.1] nssa[R5]ospf 1[R5-ospf-1] area 0.0.0.1[R5-ospf-1-area-0.0.0.1] nssa#再次查看R5的OSPF路由表R5display ospf routingOSPF Process 1 with Router ID 10.0.5.5Routing TablesRouting for NetworkDestination Cost Type NextHop AdvRouter Area10.0.45.0/24 1 Transit 10.0.45.5 10.0.5.5 0.0.0.110.0.1.0/24 3 Inter-area 10.0.45.4 10.0.4.4 0.0.0.110.0.3.0/24 2 Inter-area 10.0.45.4 10.0.4.4 0.0.0.110.0.4.0/24 1 Inter-area 10.0.45.4 10.0.4.4 0.0.0.110.0.13.0/24 3 Inter-area 10.0.45.4 10.0.4.4 0.0.0.110.0.23.0/24 3 Inter-area 10.0.45.4 10.0.4.4 0.0.0.110.0.34.0/24 2 Inter-area 10.0.45.4 10.0.4.4 0.0.0.1Routing forNSSAsDestination Cost Type Tag NextHop AdvRouter0.0.0.0/01 Type2 1 10.0.45.410.0.4.4Total Nets: 8Intra Area: 1 Inter Area: 6 ASE: 0 NSSA: 1此时不存在由R2发布的缺省路由存在一条由R4发布的Type-7 LSA描述的OSPF缺省路由。#查看R5 LSDBR5display ospf lsdbOSPF Process 1 with Router ID 10.0.5.5Link State DatabaseArea: 0.0.0.1Type LinkState ID AdvRouter Age Len Sequence MetricRouter 10.0.5.5 10.0.5.5 100 36 80000005 1Router 10.0.4.4 10.0.4.4 105 36 80000005 1Network 10.0.45.5 10.0.5.5 100 32 80000002 0Sum-Net 10.0.34.0 10.0.4.4 151 28 80000001 1Sum-Net 10.0.13.0 10.0.4.4 151 28 80000001 2Sum-Net 10.0.3.0 10.0.4.4 151 28 80000001 1Sum-Net 10.0.1.0 10.0.4.4 151 28 80000001 2Sum-Net 10.0.4.0 10.0.4.4 151 28 80000001 0Sum-Net 10.0.23.0 10.0.4.4 151 28 80000001 2NSSA10.0.5.010.0.5.514336800000011NSSA10.0.45.010.0.5.514336800000021NSSA0.0.0.010.0.4.415136800000011此时不存在Type-4 LSA、Type-5 LSA外部路由以Type-7 LSANSSA的形式存在。#查看R4的OSPF路由表[R4]display ospf routingOSPF Process 1 with Router ID 10.0.4.4Routing TablesRouting for NetworkDestination Cost Type NextHop AdvRouter Area10.0.4.0/24 0 Stub 10.0.4.4 10.0.4.4 0.0.0.010.0.34.0/24 1 Transit 10.0.34.4 10.0.4.4 0.0.0.010.0.45.0/24 1 Transit 10.0.45.4 10.0.4.4 0.0.0.110.0.1.0/24 2 Inter-area 10.0.34.3 10.0.3.3 0.0.0.010.0.3.0/24 1 Stub 10.0.34.3 10.0.3.3 0.0.0.010.0.13.0/24 2 Inter-area 10.0.34.3 10.0.3.3 0.0.0.010.0.23.0/24 2 Inter-area 10.0.34.3 10.0.3.3 0.0.0.0Routing for ASEsDestination Cost Type Tag NextHop AdvRouter0.0.0.0/0 22 Type1 1 10.0.34.3 10.0.2.2Routing for NSSAsDestination Cost Type Tag NextHop AdvRouter10.0.5.0/24 1 Type2 1 10.0.45.5 10.0.5.5Total Nets: 9Intra Area: 4 Inter Area: 3 ASE: 1 NSSA: 1R5所引入的外部路由10.0.5.0/24由Type-7 LSA所描述。以上验证了NSSA区域阻断了外部的Type-4 LSA、Type-5 LSA进入并且ABR会向区域内下发一条由Type-7 LSA描述的默认路由。ASBR向NSSA区域内下发Type-7 LSA描述本区域中引入的外部路由。步骤 7观察NSSA对OSPF产生的影响#在R4上查看OSPF概要信息R4display ospf briefOSPF Process 1 with Router ID 10.0.4.4OSPF Protocol InformationRouterID: 10.0.4.4Border Router: AREA AS NSSAMulti-VPN-Instance is not enabledGlobal DS-TE Mode: Non-Standard IETF ModeSpf-schedule-interval: max 10000ms, start 500ms, hold 1000msDefault ASE parameters: Metric: 1 Tag: 1 Type: 2Route Preference: 10ASE Route Preference: 150SPF Computation Count: 22RFC 1583 CompatibleRetransmission limitation is disabledArea Count: 2 Nssa Area Count: 1ExChange/Loading Neighbors: 0Area: 0.0.0.0 (MPLS TE not enabled)Authtype: None Area flag: NormalSPF scheduled Count: 22ExChange/Loading Neighbors: 0Router ID conflict state: NormalInterface: 10.0.4.4 (LoopBack0)Cost: 0 State: DR Type: Broadcast MTU: 1500Priority: 1Designated Router: 10.0.4.4Backup Designated Router: 0.0.0.0Timers: Hello 10 , Dead 40 , Poll 120 , Retransmit 5 , Transmit Delay 1Interface: 10.0.34.4 (GigabitEthernet0/0/3)Cost: 1 State: BDR Type: Broadcast MTU: 1500Priority: 1Designated Router: 10.0.34.3Backup Designated Router: 10.0.34.4Timers: Hello 10 , Dead 40 , Poll 120 , Retransmit 5 , Transmit Delay 1Area: 0.0.0.1 (MPLS TE not enabled)Authtype: None Area flag: NSSASPF scheduled Count: 6ExChange/Loading Neighbors: 0NSSA Translator State: ElectedRouter ID conflict state: NormalInterface: 10.0.45.4 (GigabitEthernet0/0/2)Cost: 1 State: BDR Type: Broadcast MTU: 1500Priority: 1Designated Router: 10.0.45.5Backup Designated Router: 10.0.45.4Timers: Hello 10 , Dead 40 , Poll 120 , Retransmit 5 , Transmit Delay 1在Border Router字段可以看到R4此时的身份为AREA AS NSSA分别代表该路由器为ABR、ASBR以及存在接口属于NSSA区域。#在R4上观察Type-7 LSA向Type-5 LSA转换的过程以10.0.5.0/24为例观察路由信息的传递过程R4display ospf lsdb nssa 10.0.5.0OSPF Process 1 with Router ID 10.0.4.4Area: 0.0.0.0Link State DatabaseArea: 0.0.0.1Link State DatabaseType : NSSALs id : 10.0.5.0Adv rtr : 10.0.5.5Ls age : 587Len : 36Options : NPseq# : 80000001chksum : 0x3336Net mask : 255.255.255.0TOS 0 Metric: 1E type : 2Forwarding Address : 10.0.45.5Tag : 1Priority : Low首先查看描述10.0.5.0/24的Type-7 LSA其options字段为NP表示该LSA可以被ABR转化成一条Type-5 LSA。#在R4上查看生成的用于描述10.0.5.0/24的Type-5 LSAR4display ospf lsdb ase 10.0.5.0OSPF Process 1 with Router ID 10.0.4.4Link State DatabaseType : ExternalLs id : 10.0.5.0Adv rtr : 10.0.4.4Ls age : 753Len : 36Options : Eseq# : 80000001chksum : 0xb6bcNet mask : 255.255.255.0TOS 0 Metric: 1E type : 2Forwarding Address : 10.0.45.5Tag : 1Priority : Low可以看到与Type-7 LSA相比其Ls id、net mask、FA地址字段内容完全相同adv rtr字段值从10.0.5.5变为了10.0.4.4说明该Type-5 LSA由R4产生。1.1.3思考题在什么场景下适合使用NSSA区域1.1.4配置参考R1设备配置#sysname R1#interface GigabitEthernet0/0/1ip address 10.0.13.1 255.255.255.0#interface LoopBack0ip address 10.0.1.1 255.255.255.0ospf network-type broadcast#ospf 1 router-id 10.0.1.1area 0.0.0.2network 10.0.1.1 0.0.0.0network 10.0.13.1 0.0.0.0stub#R2设备配置#sysname R2#interface GigabitEthernet0/0/2ip address 10.0.23.2 255.255.255.0#interface LoopBack0ip address 10.0.2.2 255.255.255.0ospf network-type broadcast#ospf 1 router-id 10.0.2.2default-route-advertise cost 20 type 1area 0.0.0.3network 10.0.23.2 0.0.0.0#ip route-static 0.0.0.0 0.0.0.0 LoopBack0#R3设备配置#sysname R3#interface GigabitEthernet0/0/1ip address 10.0.13.3 255.255.255.0#interface GigabitEthernet0/0/2ip address 10.0.34.3 255.255.255.0#interface GigabitEthernet0/0/3ip address 10.0.23.3 255.255.255.0#interface LoopBack0ip address 10.0.3.3 255.255.255.0ospf network-type broadcast#ospf 1 router-id 10.0.3.3area 0.0.0.0network 10.0.3.3 0.0.0.0network 10.0.34.3 0.0.0.0area 0.0.0.2network 10.0.13.3 0.0.0.0stub no-summaryarea 0.0.0.3network 10.0.23.3 0.0.0.0#R4设备配置#sysname R4#interface GigabitEthernet0/0/2ip address 10.0.45.4 255.255.255.0#interface GigabitEthernet0/0/3ip address 10.0.34.4 255.255.255.0#interface LoopBack0ip address 10.0.4.4 255.255.255.0ospf network-type broadcast#ospf 1 router-id 10.0.4.4area 0.0.0.0network 10.0.4.4 0.0.0.0network 10.0.34.4 0.0.0.0area 0.0.0.1network 10.0.45.4 0.0.0.0nssa#R5设备配置#sysname R5#interface GigabitEthernet0/0/3ip address 10.0.45.5 255.255.255.0#interface LoopBack0ip address 10.0.5.5 255.255.255.0ospf network-type broadcast#ospf 1 router-id 10.0.5.5import-route directarea 0.0.0.1network 10.0.45.5 0.0.0.0nssa#