BSCI实验之十五:OSPF在帧中继点到多点模式下的配置

实验拓扑：

 

试验要求： R4 R2 R3 通过R1- FR 相连，形成 hub and spoke 网络拓扑， R1 为模拟帧中继交换机，R4为 hub 路由器， R2 R3 为 spoke 路由器， R4 R3 R2 采用点对多点接口。全部用物理接口并全起 OSPF 。

实验目的：接口静态映射、点到多点模式特征、配置和调试。

 

一、帧中继交换机配置

 

在 R1 上进行如下配置

hostname FRS

frame-relay switching

 

interface Serial1/0

 no ip address

 encapsulation frame-relay            ------接口封装为帧中继

clock rate 2016000                        ------配置时钟

 frame-relay intf-type dce

 frame-relay route 201 interface Serial1/3 102      ----路由设置

 

interface Serial1/2

 no ip address

 encapsulation frame-relay

 no ip route-cache

clock rate 2016000

 frame-relay intf-type dce

 frame-relay route 301 interface Serial1/3 103

 

interface Serial1/3

 no ip address

 encapsulation frame-relay

 no ip route-cache

clock rate 2016000

 frame-relay intf-type dce

 frame-relay route 102 interface Serial1/0 201

 frame-relay route 103 interface Serial1/2 301

 

二、远程路由器上的配置

 

R4 配置：

 

hostname HQ

interface Loopback1

 ip address 10.1.1.1 255.255.255.0

 ip ospf network point-to-point

interface Serial1/3

 ip address 10.1.123.1 255.255.255.0

 encapsulation frame-relay

 ip ospf network point-to-multipoint     ----- the default network type is non-broadcast

frame-relay map ip 10.1.123.1 102     ---- 使得可以 Ping 通自己

 frame-relay map ip 10.1.123.2 102 broadcast     ---- 帧中继静态映射

 frame-relay map ip 10.1.123.3 103 broadcast

 no frame-relay inverse-arp                    ---- 关闭动态 ARP 映射

!         

router ospf 1      

 log-adjacency-changes

 network 10.1.1.0 0.0.0.255 area 0

 network 10.1.123.0 0.0.0.255 area 0

--------------------------------------------------------------

R2 配置：

hostname EAST

interface Loopback2

 ip address 10.1.2.1 255.255.255.0

 ip ospf network point-to-point

interface Serial1/0

 ip address 10.1.123.2 255.255.255.0

 encapsulation frame-relay

 ip ospf network point-to-multipoint      -----/指明为点到多点模式。 注：如此设为 ip ospf nei broadcast 则为 BMA 模式/

frame-relay map ip 10.1.123.1 201 broadcast

 frame-relay map ip 10.1.123.2 201

 frame-relay map ip 10.1.123.3 201 broadcast

 no frame-relay inverse-arp

interface Serial1/1

 ip address 10.1.23.2 255.255.255.0

 

router ospf 1

network 10.1.2.0 0.0.0.255 area 0

 network 10.1.23.0 0.0.0.255 area 0

 network 10.1.123.0 0.0.0.255 area 0

--------------------------------------------------------------

R3 配置：

hostname WEST

interface Loopback3

 ip address 10.1.3.1 255.255.255.0

 ip ospf network point-to-point

interface Serial1/1

 ip address 10.1.23.3 255.255.255.0

interface Serial1/2

 ip address 10.1.123.3 255.255.255.0

 encapsulation frame-relay

 ip ospf network point-to-multipoint

frame-relay map ip 10.1.123.1 301 broadcast

 frame-relay map ip 10.1.123.2 301 broadcast

 frame-relay map ip 10.1.123.3 301

 no frame-relay inverse-arp

 

router ospf 1

network 10.1.3.0 0.0.0.255 area 0

 network 10.1.23.0 0.0.0.255 area 0

 network 10.1.123.0 0.0.0.255 area 0

 

三、调试

 

HQ#sh ip route     ----查看路由表，O代表通过OSPF学到
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

     10.0.0.0/8 is variably subnetted, 7 subnets, 2 masks
O       10.1.3.0/24 [110/65] via 10.1.123.3, 00:00:28, Serial1/3
O       10.1.2.0/24 [110/65] via 10.1.123.2, 00:00:28, Serial1/3
C       10.1.1.0/24 is directly connected, Loopback1
O       10.1.23.0/24 [110/128] via 10.1.123.3, 00:00:28, Serial1/3
                     [110/128] via 10.1.123.2, 00:00:28, Serial1/3
C       10.1.123.0/24 is directly connected, Serial1/3
O       10.1.123.2/32 [110/64] via 10.1.123.2, 00:00:28, Serial1/3
O       10.1.123.3/32 [110/64] via 10.1.123.3, 00:00:28, Serial1/3

 

HQ#sh ip ospf int s1/3      -----查看接口
Serial1/3 is up, line protocol is up
  Internet Address 10.1.123.1/24, Area 0
  Process ID 1, Router ID 10.1.1.1, Network Type POINT_TO_MULTIPOINT, Cost: 64
  Transmit Delay is 1 sec, State POINT_TO_MULTIPOINT         ----点到多点
  Timer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5
    oob-resync timeout 120
    Hello due in 00:00:15
  ……

  Neighbor Count is 2, Adjacent neighbor count is 2
    Adjacent with neighbor 10.1.2.1
    Adjacent with neighbor 10.1.3.1
  Suppress hello for 0 neighbor(s)

 

HQ#sh ip ospf data

            OSPF Router with ID (10.1.1.1) (Process ID 1)

                Router Link States (Area 0)

Link ID         ADV Router      Age         Seq#       Checksum Link count
10.1.1.1        10.1.1.1        146         0x80000003 0x007039 4
10.1.2.1        10.1.2.1        147         0x80000005 0x00E2B1 5
10.1.3.1        10.1.3.1        146         0x80000007 0x002F5E 5

HQ#sh ip ospf nei       -----查看邻居关系，可见没有DR和BDR关系存在

Neighbor ID     Pri   State           Dead Time   Address         Interface
10.1.2.1          0   FULL/  -        00:01:58    10.1.123.2      Serial1/3
10.1.3.1          0   FULL/  -        00:01:57    10.1.123.3      Serial1/3

 

AST#sh ip ospf data

            OSPF Router with ID (10.1.2.1) (Process ID 1)

                Router Link States (Area 0)

Link ID         ADV Router      Age         Seq#       Checksum Link count
10.1.1.1        10.1.1.1        191         0x80000003 0x007039 4
10.1.2.1        10.1.2.1        189         0x80000005 0x00E2B1 5
10.1.3.1        10.1.3.1        191         0x80000007 0x002F5E 5

 

EAST#sh ip ospf nei

Neighbor ID     Pri   State           Dead Time   Address         Interface
10.1.1.1          0   FULL/  -        00:01:57    10.1.123.1      Serial1/0
10.1.3.1          0   FULL/  -        00:00:10    10.1.23.3       Serial1/1

 

实验总结： 在采用点对多点接口的时候OSPF路由协议的配置，帧中继接口在同一子网，并且邻居关系是自动建立，无需手动指定邻居，无DR/BDR选举，默认的HELLO时间间隔为30秒，等待时间和死亡时间为HELLO时间间隔的4倍，120秒。