OSPF 学习笔记

1、网络拓扑

2、R1\R2\R3 OSPF配置

R1：
enable
config t
no ip domain lookup
line console 0
no exec-timeout
logging synchronous
exit


interface f0/0
no shutdown
ip add 1.1.123.1 255.255.255.224
exit

interface loopback 0
ip add 10.10.1.1 255.255.255.0
no shutdown
exit
end


R2：
enable
config t
no ip domain lookup
line console 0
no exec-timeout
logging synchronous
exit


interface f0/0
no shutdown
ip add 1.1.123.2 255.255.255.224
exit

interface s1/0
no shutdown
ip add 1.1.24.1 255.255.255.248
exit

interface loopback 0
ip add 10.10.2.2 255.255.255.0
no shutdown
exit
end


R3：
enable
config t
no ip domain lookup
line console 0
no exec-timeout
logging synchronous
exit


interface f0/0
no shutdown
ip add 1.1.123.3 255.255.255.224
exit


interface s1/1
no shutdown
ip add 1.1.34.1 255.255.255.248
exit

interface loopback 0
ip add 10.10.3.3 255.255.255.0
no shutdown
exit
end




R4 ：
enable
config t
no ip domain lookup
line console 0
no exec-timeout
logging synchronous
exit


interface s1/0
no shutdown
ip add 1.1.24.2 255.255.255.248
exit

interface s1/1
no shutdown
ip add 1.1.34.2 255.255.255.248
exit

interface s1/2
no shutdown
ip add 1.1.45.2 255.255.255.0
exit

interface loopback 0
no shut
ip address 10.10.4.4 255.255.255.0
end

      



R5 ：
enable
config t
no ip domain lookup
line console 0
no exec-timeout
logging synchronous
exit

interface s1/2
no shutdown
ip add 1.1.45.1 255.255.255.0
exit

interface loopback 0
no shut
ip add 10.10.5.5 255.255.255.0
end

R1-OSPF-Router config 

config t
router ospf 1
router-id 1.1.1.1
network 1.1.123.1 0.0.0.0 area 2
network 10.10.1.1 0.0.0.0 area 2
end

R2-OSPF-Router config 

config t
router ospf 1
router-id 2.2.2.2
network 1.1.123.2 0.0.0.0 area 2
network 10.10.2.2 0.0.0.0 area 2
end

config t
router ospf 2
router-id 2.2.2.3
network 1.1.24.1 0.0.0.0 area 2
end



q 


R3-OSPF-Router config 

config t
router ospf 1
router-id 3.3.3.3
network 1.1.123.3 0.0.0.0 area 2
network 10.10.3.3 0.0.0.0 area 2
end

config t
router ospf 2
router-id 3.3.3.3
network 1.1.34.1  0.0.0.0 area 2
end 


R4-OSPF-Router config 

config t
router ospf 2
router-id 4.4.4.4
network 1.1.24.2 0.0.0.0 area 2
network 1.1.34.2 0.0.0.0 area 2
network 1.1.45.2 0.0.0.0 area 2
network 10.10.4.4 0.0.0.0 area 2
end


R5-OSPF-Router config
config t
router ospf 2
router-id 5.5.5.5
network 1.1.45.1 0.0.0.0 area 2
network 10.10.5.5 0.0.0.0 area 2
end 

3、 OSPF配置

R3#show ip ospf neighbor 

Neighbor ID     Pri   State           Dead Time   Address         Interface
1.1.1.1           1   FULL/BDR        00:00:33    1.1.123.1       FastEthernet0/0
2.2.2.2           1   FULL/DR         00:00:32    1.1.123.2       FastEthernet0/0

• DR: Designate router，指定路由器
• BDR：Backup Disignate router，备用指定路由器
• DROthers：其余非DR/BDR路由器
• DR/BDR选举规则：先比较接口优先级，越大越优先。优先级相同，比较RID，越大越优先

R3#show ip ospf interface f0/0
FastEthernet0/0 is up, line protocol is up 
  Internet Address 1.1.123.3/27, Area 2 
  Process ID 1, Router ID 3.3.3.3, Network Type BROADCAST, Cost: 1
  Transmit Delay is 1 sec, State DROTHER, Priority 1 
  Designated Router (ID) 2.2.2.2, Interface address 1.1.123.2
  Backup Designated router (ID) 1.1.1.1, Interface address 1.1.123.1
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
    oob-resync timeout 40
    Hello due in 00:00:02
  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 2, Adjacent neighbor count is 2 
    Adjacent with neighbor 1.1.1.1  (Backup Designated Router)
    Adjacent with neighbor 2.2.2.2  (Designated Router)
  Suppress hello for 0 neighbor(s)
R3#