OSPF协议中LSA1与LSA2实验

1、OSPF协议中LSA1与LSA2一、LSA1每一台OSPF路由器都会产生自己的LSA1，用以描述详细描述本身的链路情况，并且会把自己的LSA1向同一区域中的OSPF路由器邻居泛洪。邻居OSPF路由器把收到的同一区域的其它OSPF路由器的LSA1再向同一区域的OSPF路由器泛洪，所有OSPF路由器都进行相同的方法对LSA1进行泛洪，最终的目的是在同一区域中所有的OSPF路由器收集到了所有OSPF路由器的LSA1也就是说，同一区域中所有OSPF路由器拥有相同的LSA1的数据。在上图的模型中，R1产生自己的LSA1，R1把自己的LSA1发送给DR（正常情况下为R3），DR（R3）再把R1的LSA1发

2、送给R2、R4，R4再把R1的LSA1发送给R5。这样R1R5就都拥有了R1的LSA1，其它的路由器执行相同的过程，那么所有路由器都拥有了相同的LSA1的数据。在R4和R5上执行show ip ospf database查看LSA1的汇总信息如下：R4的database数据R4#show ip ospf data OSPF Router with ID (192.168.5.4) (Process ID 1)Router Link States (Area 0)Link ID ADV Router Age Seq# Checksum Link count192.168.5.1 192.168.

3、5.1 1873 0x80000003 0x00E4FE 2192.168.5.4 192.168.5.4 1871 0x80000003 0x001EB9 2192.168.8.1 192.168.8.1 1859 0x80000003 0x00A144 3192.168.8.2 192.168.8.2 1859 0x80000003 0x00636C 2192.168.9.1 192.168.9.1 1872 0x80000002 0x009C36 2R5的database数据R5#show ip ospf database OSPF Router with ID (192.168.8.2

4、) (Process ID 1)Router Link States (Area 0)Link ID ADV Router Age Seq# Checksum Link count192.168.5.1 192.168.5.1 1899 0x80000003 0x00E4FE 2192.168.5.4 192.168.5.4 1899 0x80000003 0x001EB9 2192.168.8.1 192.168.8.1 1885 0x80000003 0x00A144 3192.168.8.2 192.168.8.2 1884 0x80000003 0x00636C 2192.168.9.

5、1 192.168.9.1 1898 0x80000002 0x009C36 2其中Link ID表示链路ID，ADV Router表示通告LSA数据的ID也就是路由器ID，这两个ID号是相同的。再从R4、R5上使用show ip ospf database router 192.168.5.4查看R4的LSA1的详细信息如下： R4的信息R4#show ip ospf database router 192.168.5.4 OSPF Router with ID (192.168.5.4) (Process ID 1)Router Link States (Area 0) LS age: 4

6、25 Options: (No TOS-capability, DC) LS Type: Router Links Link State ID: 192.168.5.4 Advertising Router: 192.168.5.4 LS Seq Number: 80000004 Checksum: 0x1CBA Length: 48 Number of Links: 2 Link connected to: a Transit Network (Link ID) Designated Router address: 192.168.5.3 (Link Data) Router Interfa

7、ce address: 192.168.5.4 Number of TOS metrics: 0 TOS 0 Metrics: 10 Link connected to: a Stub Network (Link ID) Network/subnet number: 192.168.4.0 (Link Data) Network Mask: 255.255.255.0 Number of TOS metrics: 0 TOS 0 Metrics: 10R5的信息R5# show ip ospf database router 192.168.5.4 OSPF Router with ID (1

8、92.168.8.2) (Process ID 1)Router Link States (Area 0) LS age: 464 Options: (No TOS-capability, DC) LS Type: Router Links Link State ID: 192.168.5.4 Advertising Router: 192.168.5.4 LS Seq Number: 80000004 Checksum: 0x1CBA Length: 48 Number of Links: 2 Link connected to: a Transit Network (Link ID) De

9、signated Router address: 192.168.5.3 (Link Data) Router Interface address: 192.168.5.4 Number of TOS metrics: 0 TOS 0 Metrics: 10 Link connected to: a Stub Network (Link ID) Network/subnet number: 192.168.4.0 (Link Data) Network Mask: 255.255.255.0 Number of TOS metrics: 0 TOS 0 Metrics: 10从上面的数据可以看

10、出，在同一区域中，所有OSPF路由器拥有相同的LSA1数据。二、LSA2OSPF协议要求一个链路只能连接两个接点，然而多路访问的网络模型，可能会存在2台以上的路由器连接到同一个子网，因此OSPF采取在多路访问的网络上选举DR的方式进行抽象，路由器只与DR建立全毗邻关系，DR相当于一个伪节点，这些路由器用LSA1来描述它们与DR之间的链路关系。OSPF协议使用LSA2来描述抽象出来的多路访问网络。LSA2则是由DR创建的，它措述了一个子网的详细信息，并且LSA2也会在同一区域中进行泛洪。在R4和R5上使用show ip ospf interface可以看到R3和R8分别为192.168.5.0子

11、网和192.168.8.0子网的DR，它们的路由器ID分别为192.168.9.1和192.168.8.2。在R4和R5上查看LSA2型数据的汇总信息如下R4查看到的信息R4#show ip ospf database OSPF Router with ID (192.168.5.4) (Process ID 1)Router Link States (Area 0)Link ID ADV Router Age Seq# Checksum Link count192.168.5.1 192.168.5.1 883 0x80000006 0x00DE02 2192.168.5.4 192.168

12、.5.4 873 0x80000006 0x0018BC 2192.168.8.1 192.168.8.1 966 0x80000006 0x009B47 3192.168.8.2 192.168.8.2 898 0x80000006 0x005D6F 2192.168.9.1 192.168.9.1 919 0x80000005 0x009639 2Net Link States (Area 0)Link ID ADV Router Age Seq# Checksum192.168.5.3 192.168.9.1 919 0x80000005 0x00621F192.168.8.2 192.

13、168.8.2 898 0x80000004 0x00B8B1R4#R5查看到的信息R5#show ip ospf database OSPF Router with ID (192.168.8.2) (Process ID 1)Router Link States (Area 0)Link ID ADV Router Age Seq# Checksum Link count192.168.5.1 192.168.5.1 955 0x80000006 0x00DE02 2192.168.5.4 192.168.5.4 946 0x80000006 0x0018BC 2192.168.8.1 1

14、92.168.8.1 1038 0x80000006 0x009B47 3192.168.8.2 192.168.8.2 967 0x80000006 0x005D6F 2192.168.9.1 192.168.9.1 991 0x80000005 0x009639 2Net Link States (Area 0)Link ID ADV Router Age Seq# Checksum192.168.5.3 192.168.9.1 991 0x80000005 0x00621F192.168.8.2 192.168.8.2 967 0x80000004 0x00B8B1LinkID表示链路的

15、ID号，AVD Router同样表示通告LSA2型数据的路由器ID，也就是路由器ID。在R4和R5上查看192.168.5.3的Net Link States的详细信息如下：R4查看到的信息R4#show ip ospf database network 192.168.5.3 OSPF Router with ID (192.168.5.4) (Process ID 1)Net Link States (Area 0) Routing Bit Set on this LSA LS age: 733 Options: (No TOS-capability, DC) LS Type: Netwo

16、rk Links Link State ID: 192.168.5.3 (address of Designated Router) Advertising Router: 192.168.9.1 LS Seq Number: 80000006 Checksum: 0x6020 Length: 40 Network Mask: /24Attached Router: 192.168.9.1Attached Router: 192.168.5.1Attached Router: 192.168.5.4Attached Router: 192.168.8.1R5查看到的信息R5#show ip o

17、spf database net 192.168.5.3 OSPF Router with ID (192.168.8.2) (Process ID 1)Net Link States (Area 0) Routing Bit Set on this LSA LS age: 1156 Options: (No TOS-capability, DC) LS Type: Network Links Link State ID: 192.168.5.3 (address of Designated Router) Advertising Router: 192.168.9.1 LS Seq Number: 80000005 Checksum: