配置单区域OSPF

实验过程：
第一步  配置R1的接口与OSPF
R1(config)#int s2/1
R1(config-if)#ip add 12.0.0 .1 255.255.255.0
R1(config-if)#no sh
R1(config-if)#router ospf 64
R1(config-router)#net 12.0.0.0 0.0.0.255 area 0
R1(config-router)# ^Z

 

第二步  配置R2的接口与OSPF
R2(config)#int s2/1
R2(config-if)#ip add 12.0.0 .2 255.255.255.0
R2(config-if)#no sh
R2(config-if)#int s2/2
R2(config-if)#ip add 23.0.0.2 255.255.255.0
R2(config-if)#no sh
R2(config-if)#router ospf 64
R2(config-router)#net 12.0.0.0 0.0.0.255 area 0
R2(config-router)#net 23.0.0.0 0.0.0.255 area 0
R2(config-router)# ^Z

 

第三步  配置R3接口与OSPF
R3(config)#int s2/1
R3(config-if)#ip add 23.0.0 .3 255.255.255.0
R3(config-if)#no sh
R3(config-if)#int s2/2
R3(config-if)#ip add 34.0.0.3 255.255.255.0
R3(config-if)#no sh
R3(config-if)#router ospf 64
R3(config-router)#net 23.0.0.3 0.0.0.0 area 0
R3(config-router)#net 34.0.0.3 0.0.0.0 area 0
R3(config-router)# ^Z

 

第四步  配置R4接口与OSPF
R4(config)#int s2/1
R4(config-if)#ip add 34.0.0.4 255.255.255.0
R4(config-if)#no sh
R4(config-if)#int s2/2
R4(config-if)#ip add 45.0.0.4 255.255.255.0
R4(config-if)#no sh
R4(config-if)#router ospf 64
R4(config-router)#net 0.0.0 .0 0.0.0.0 area 0
R4(config-router)# ^Z

 

第五步  配置R5接口与OSPF
R5(config)#int s2/2
R5(config-if)#ip add 45.0.0.5 255.255.255.0
R5(config-if)#no sh
R5(config-if)#router ospf 64
R5(config-router)#net 45.0.0.5 0.0.0 .0 area 0
R5(config-router)# ^Z

 

第六步  在R1上检查OSPF的运行情况
R1#show ip ospf interface
//  查看OSPF接口
Serial2/1 is up, line protocol is up
  Internet Address 12.0.0 .1/24, Area 0
//  接口S2/1在OSPF区域0下
  Process ID 64, Router ID 12.0.0.1, Network Type POINT_TO_POINT, Cost: 64
//  OSPF 在Serial接口上的Cost默认为64，网络类型为Pont_to_Point
  Transmit Delay is 1 sec, State POINT_TO_POINT
//  在Cisco上，默认为1秒，即已接收到的LSA老化时间速度
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
//  在Cisco上，默认的Hello包时间间隔为10秒，死亡间隔时间为40秒，等待时间为40秒，重传时间为5秒
    oob-resync timeout 40
    Hello due in 00:00:08
  Supports Link-local Signaling (LLS)
  Cisco NSF helper support enabled
  IETF NSF helper support enabled
  Index 1/1, flood queue length 0
  Next 0x0(0)/0x0(0)
  Last flood scan length is 1, maximum is 1
  Last flood scan time is 0 msec, maximum is 0 msec
  Neighbor Count is 1, Adjacent neighbor count is 1
    Adjacent with neighbor 23.0.0.2
  Suppress hello for 0 neighbor(s)
 
R1#show ip ospf neighbor
//  查看OSPF的邻居
Neighbor ID     Pri   State           Dead Time   Address         Interface
23.0.0.2          0   FULL/  -        00:00:35    12.0.0.2        Serial2/1

R1#show ip ospf neighbor detail
//  查看OSPF的邻居详细情况
 Neighbor 23.0.0 .2, interface address 12.0.0.2
    In the area 0 via interface Serial2/1
    Neighbor priority is 0, State is FULL, 6 state changes
    DR is 0.0.0.0 BDR is 0.0.0.0
//  在点到点接口中，没有选举DR/BDR
    Options is 0x52
    LLS Options is 0x1 (LR)
    Dead timer due in 00:00:32
    Neighbor is up for 00:12:46
    Index 1/1, retransmission queue length 0, number of retransmission 0
    First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0)
    Last retransmission scan length is 0, maximum is 0
    Last retransmission scan time is 0 msec, maximum is 0 msec

R1#show ip protocols
//  查看协议运行情况
Routing Protocol is "ospf 64"
  Outgoing update filter list for all interfaces is not set
  Incoming update filter list for all interfaces is not set
  Router ID 12.0.0 .1
  Number of areas in this router is 1. 1 normal 0 stub 0 nssa
  Maximum path: 4
  Routing for Networks:
    12.0.0.0 0.0.0.255 area 0
 Reference bandwidth unit is 100 mbps
  Routing Information Sources:
    Gateway         Distance      Last Update
    12.0.0.1             110      00:13:29
    23.0.0.2             110      00:12:20
    34.0.0.3             110      00:11:19
    45.0.0.4             110      00:10:20
  Distance: (default is 110)

R1#show ip ospf statistics
//  查看R1的OSPF状态
            OSPF Router with ID ( 12.0.0 .1) (Process ID 64)

  Area 0: SPF algorithm executed 12 times
//  在Area 0中SPF算法已经计算了12次
  Summary OSPF SPF statistic

  SPF calculation time
//  下面显示了处理各种类型的LSA所花费的时间
Delta T   Intra D-Intra Summ    D-Summ  Ext     D-Ext   Total   Reason
00:13:58   0    0       0       0       0       0       0       R,
00:13:29   0    0       0       0       0       0       0       R,
00:13:19   0    0       0       0       0       0       0       R,
00:12:48   0    0       0       0       4       0       4       R,
00:12:23   0    0       0       0       0       0       0       R,
00:11:48   0    4       0       0       0       0       4       R,
00:11:32   4    0       0       0       0       0       4       R,
00:11:22   0    4       0       0       0       0       4       R,
00:10:48   4    0       0       0       0       0       4       R,
00:05:05   4    0       0       0       0       0       4       R,
//  Reason 是记录引起SPF运算的原因
     N → Type 2 Networks LSA发生改变
     R → Type 1 Router LSA发生改变
     SA → ASBR LSA发生改变
     SN → Summary Networks（SN）LSA发生改变
     X → Type 7外部类型7 LSA发生改变

R1#show ip ospf
//  查看OSPF运行情况
 Routing Process "ospf 64" with ID 12.0.0 .1
//  OSPF 的进程号是64，OSPF的Router ID是12.0.0.1
 Start time: 00:01:47.792, Time elapsed: 00:15:16.752
 Supports only single TOS(TOS0) routes
 Supports opaque LSA
 Supports Link-local Signaling (LLS)
 Supports area transit capability
 Router is not originating router-LSAs with maximum metric
 Initial SPF schedule delay 5000 msecs
//  SPF 算法启动的时延，可以使用timer throttle spf进行设置
 Minimum hold time between two consecutive SPFs 10000 msecs
//  在连续的SPF计算之间最小hold time，可以使用timer throttle spf进行配置
 Maximum wait time between two consecutive SPFs 10000 msecs
//  在连续的SPF计算之间最大的等待时间，可以使用timer throttle spf进行配置
 Incremental-SPF disabled
 Minimum LSA interval 5 secs
//  最小的LSA间隔时间为5秒
 Minimum LSA arrival 1000 msecs
 LSA group pacing timer 240 secs
 Interface flood pacing timer 33 msecs
 Retransmission pacing timer 66 msecs
 Number of external LSA 0. Checksum Sum 0x000000
 Number of opaque AS LSA 0. Checksum Sum 0x000000
 Number of DCbitless external and opaque AS LSA 0
 Number of DoNotAge external and opaque AS LSA 0
 Number of areas in this router is 1. 1 normal 0 stub 0 nssa
 Number of areas transit capable is 0
 External flood list length 0
 IETF NSF helper support enabled
 Cisco NSF helper support enabled
    Area BACKBONE(0)
        Number of interfaces in this area is 1
        Area has no authentication
        SPF algorithm last executed 00:05:37.784 ago
        SPF algorithm executed 12 times
        Area ranges are
        Number of LSA 5. Checksum Sum 0x0204EC
        Number of opaque link LSA 0. Checksum Sum 0x000000
        Number of DCbitless LSA 0
        Number of indication LSA 0
        Number of DoNotAge LSA 0
        Flood list length 0

 

第七步  检查OSPF路由表
R1#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

     34.0.0.0/24 is subnetted, 1 subnets
O       34.0.0.0 [110/192] vi a 12.0.0 .2, 00:12:32, Serial2/1
     23.0.0.0/24 is subnetted, 1 subnets
O       23.0.0.0 [110/128] vi a 12.0.0 .2, 00:13:33, Serial2/1
     12.0.0.0/24 is subnetted, 1 subnets
C       12.0.0.0 is directly connected, Serial2/1
     45.0.0.0/24 is subnetted, 1 subnets
O       45.0.0.0 [110/256] vi a 12.0.0 .2, 00:11:33, Serial2/1

 

第八步  在R1上查看OSPF数据库
R1#show ip ospf database

            OSPF Router with ID ( 12.0.0 .1) (Process ID 64)

                Router Link States (Area 0)
//  在R1的OSPF数据库中只有Router Link类型的LSA
Link ID         ADV Router      Age         Seq#       Checksum Link count
12.0.0 .1        12.0.0.1        888         0x80000004 0x005401 2
23.0.0.2        23.0.0.2        824         0x80000004 0x 00A 6AD 4
34.0.0.3        34.0.0.3        774         0x80000003 0x 0052A 4 4
45.0.0.4        45.0.0.4        387         0x80000004 0x00ACF5 4
45.0.0.5        45.0.0.5        389         0x80000001 0x000AA5 2

R1#show ip ospf database database-summary
//  查看R1的OSPF数据库的统计信息
            OSPF Router with ID ( 12.0.0 .1) (Process ID 64)

Area 0 database summary
  LSA Type      Count    Delete   Maxage
  Router        5        0        0      
//  在R1的Area 0有Router类型的LSA共5个
  Network       0        0        0      
  Summary Net   0        0        0      
  Summary ASBR  0        0        0      
  Type-7 Ext    0        0        0      
    Prefixes redistributed in Type-7  0
  Opaque Link   0        0        0      
  Opaque Area   0        0        0      
  Subtotal      5        0        0      

Process 64 database summary
  LSA Type      Count    Delete   Maxage
  Router        5        0        0      
  Network       0        0        0      
  Summary Net   0        0        0      
  Summary ASBR  0        0        0      
  Type-7 Ext    0        0        0      
  Opaque Link   0        0        0      
  Opaque Area   0        0        0      
  Type-5 Ext    0        0        0      
      Prefixes redistributed in Type-5  0
  Opaque AS     0        0        0      
  Non-self      4      
  Total         5        0        0      

R1#show ip ospf database router 12.0.0 .1
//  查看OSPF数据库中关于12.0.0.1的详细信息
            OSPF Router with ID (12.0.0.1) (Process ID 64)

                Router Link States (Area 0)

  LS age: 950
//  老化时间，总是从0开始
  Options: (No TOS-capability, DC)
  LS Type: Router Links
//  这是一个Router LSA
  Link State ID: 12.0.0 .1
//  R1 的Router ID
  Advertising Router: 12.0.0.1
  LS Seq Number: 80000004
  Checksum: 0x5401
  Length: 48
  Number of Links: 2

    Link connected to: another Router (point-to-point)
//  注明连接到另一台路由器的网络类型为Point_to_Point
     (Link ID) Neighboring Router ID: 23.0.0 .2
//  邻居的Router ID，即R2的Router ID 12.0.0.2
     (Link Data) Router Interface address: 12.0.0.1
//  本路由器的接口地址，即R1的12.0.0.1
      Number of TOS metrics: 0
       TOS 0 Metrics: 64
//  到达这个接口的Cost为64
    Link connected to: a Stub Network
     (Link ID) Network/subnet number: 12.0.0.0
//  IP 网络号
     (Link Data) Network Mask: 255.255.255.0
//  接口的掩码
      Number of TOS metrics: 0
       TOS 0 Metrics: 64

R1#show ip ospf database router 23.0.0 .2
//  查看R2的12.0.0.2 OSPF数据库信息
            OSPF Router with ID (12.0.0.1) (Process ID 64)

                Router Link States (Area 0)

  LS age: 949
  Options: (No TOS-capability, DC)
  LS Type: Router Links
//  这是一个1型的Router LSA
  Link State ID: 23.0.0 .2
//  R2 的Router ID
  Advertising Router: 23.0.0.2
  LS Seq Number: 80000004
  Checksum: 0xA6AD
  Length: 72
  Number of Links: 4

    Link connected to: another Router (point-to-point)
     (Link ID) Neighboring Router ID: 34.0.0.3
     (Link Data) Router Interface address: 23.0.0 .2
      Number of TOS metrics: 0
       TOS 0 Metrics: 64

    Link connected to: a Stub Network
     (Link ID) Network/subnet number: 23.0.0 .0
     (Link Data) Network Mask: 255.255.255.0
      Number of TOS metrics: 0
       TOS 0 Metrics: 64

    Link connected to: another Router (point-to-point)
     (Link ID) Neighboring Router ID: 12.0.0 .1
     (Link Data) Router Interface address: 12.0.0.2
      Number of TOS metrics: 0
       TOS 0 Metrics: 64

    Link connected to: a Stub Network
     (Link ID) Network/subnet number: 12.0.0 .0
     (Link Data) Network Mask: 255.255.255.0
      Number of TOS metrics: 0
       TOS 0 Metrics: 64

 

第九步  查看其他路由器路由的学习情况
R2#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

     34.0.0.0/24 is subnetted, 1 subnets
O       34.0.0.0 [110/128] vi a 23.0.0 .3, 00:15:40, Serial2/2
     23.0.0.0/24 is subnetted, 1 subnets
C       23.0.0.0 is directly connected, Serial2/2
     12.0.0.0/24 is subnetted, 1 subnets
C       12.0.0.0 is directly connected, Serial2/1
     45.0.0.0/24 is subnetted, 1 subnets
O       45.0.0.0 [110/192] vi a 23.0.0 .3, 00:14:40, Serial2/2

R3#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

     34.0.0.0/24 is subnetted, 1 subnets
C       34.0.0.0 is directly connected, Serial2/2
     23.0.0 .0/24 is subnetted, 1 subnets
C       23.0.0.0 is directly connected, Serial2/1
     12.0.0.0/24 is subnetted, 1 subnets
O       12.0.0.0 [110/128] vi a 23.0.0 .2, 00:16:20, Serial2/1
     45.0.0.0/24 is subnetted, 1 subnets
O       45.0.0.0 [110/128] via 34.0.0.4, 00:14:45, Serial2/2

R4#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

     34.0.0.0/24 is subnetted, 1 subnets
C       34.0.0.0 is directly connected, Serial2/1
     23.0.0 .0/24 is subnetted, 1 subnets
O       23.0.0.0 [110/128] via 34.0.0.3, 00:15:29, Serial2/1
     12.0.0.0/24 is subnetted, 1 subnets
O       12.0.0.0 [110/192] via 34.0.0.3, 00:15:29, Serial2/1
     45.0.0.0/24 is subnetted, 1 subnets
C       45.0.0.0 is directly connected, Serial2/2

R5#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

     34.0.0.0/24 is subnetted, 1 subnets
O       34.0.0.0 [110/128] via 45.0.0.4, 00:09:27, Serial2/2
     23.0.0 .0/24 is subnetted, 1 subnets
O       23.0.0.0 [110/192] via 45.0.0.4, 00:09:27, Serial2/2
     12.0.0.0/24 is subnetted, 1 subnets
O       12.0.0.0 [110/256] via 45.0.0.4, 00:09:27, Serial2/2
     45.0.0.0/24 is subnetted, 1 subnets
C       45.0.0.0 is directly connected, Serial2/2
R5#

注：HelloInterval、RouterDeadInterval、WaitTimer和RxmtInterval的区别
1. HelloInterval
在接口上传送两个Hello包之间的周期性间隔时间，此时间在从接口发送的hello数据包中通告，广播型网络缺省为10s，非广播型网络缺省为30s，可以用ip ospf tello-interval命令更改。

2. RouterDeadInterval
指宣告邻居路由器无效前，本地路由器从与一个接口相连的网络侦听到来自于邻居路由器的一个Hello数据包所经历的时间，缺省为HelloInterval的4倍，可以用ip ospf dead-interval命令更改

3. Wait Timer
开始选取DR和BDR之前，路由器等待邻居路由器的Hello数据包通告DR和BDR的时长。等待计时器的时间长度就是RouterDeadInterval的时间

4. RxmtInterval
在没有得到确认情况下，路由器重传OSPF数据包要等待的时间长度，通过retransmit表示，可以用ip ospf retransmit-interval命令更改