ospf实验分步作（三）
内容：
OSPF实验8：OSPF Network Type Loopback
OSPF实验9：OSPF Virtual Links - Repairing Area 0
OSPF实验8：OSPF Network Type Loopback
Objective: Configure OSPF area 0 . the Ethernet and Loopback0 interfaces of
R1 andR2. The Loopback networks should appear in the routing table with a mask of /8
拓扑：（实验拓扑来自IEWB)
配置参考
R1 e0/0 10.0.0.1/8
R2 e0/0 10.0.0.2/8
R1 Loopback0 1.1.1.1/8
R2 Loopback0 2.2.2.2/8
All interface to area 0
Examine the routing tables or R1 and R2 and note the mask of the OSPF
routes to the Loopback interfaces
Configure the OSPF network type point-to-point . R1 and R2's
Loopback0 interfaces
模拟器ospf8.net配置
# OSPF实验8：OSPF Network Type Loopback
autostart = False
eghostios = true
sparsemem = True
[localhost]
port = 7200
udp = 11000
workingdir = ..\tmp\
`3640`
image = ..\IOS\unzip-c3640-ik9o3s-mz.124-10.bin
model = 3640
idlepc = 0x605c9218
exec_area = 64
confreg = 0x2142
# mmap = False
ram = 256
slot0 = NM-1E
`router R1`
model = 3640
console = 3001
exec_area = 64
e0/0 = SW 1
`router R2`
console = 3002
model = 3640
exec_area = 64
e0/0 = SW 2
`ethsw SW`
1 = access 1
2 = access 1
配置
Ｒ１上的配置
Ｒ２上的配置
在Ｒ１和Ｒ２上的loopback接口缺省的网络类型为都LOOPBACK。接口被视为“a stub host”
检查路由表，结果回环地址被当作一台主机地址，掩码位３２，无论回环接口的掩码是多少。
下面把Ｒ１和Ｒ２接口的网络类型都设置成point-to-point。如红色方框内配置。（这里列出Ｒ１的配置）。
再检查路由表如下:
R1中通过OSPF学习到的路由条目：2.0.0.0/8 ，这里的掩码是8位。这是R2路由器loopback0 接口上实际掩码位。这是因为你在loopback0接口上配置了OSPF类型为point-to-point。不再视为主机地址。
R2中对2.0.0.0/8的解释与上面类同。
OSPF实验9：OSPF Virtual Links - Repairing Area 0
Objective: Configure the OSPF domain between R1, R2, R3, R4, and R5 per
the diagram. Ensure that connectivity is maintained between R4 and
R5 if the link between R1 and R2 is down
配置参考
按上图配置R1, R2, R3, R4, R5的IP地址 。
配置帧中继封装R1 s1/0,R2 s1/0，配置 R1 和R2 三层到二层的映射。
配置R1和R4之间 VLAN 4 网段，R2和R5之间的VLAN B，R1和R2之间的帧中继网段都划分到OSPF 区域0
R1 ,R2的S1/0 : OSPF network type: point-to-point
配置 R1 & R3 and R2 & R3 为area 1
用R1 E0/0 ,R2 E0/0 上接口的IP地址分步作为R1和R2的ospf router-id
在R1与R2之间area 1内配置OSPF 虚拟链路 。
模拟器ospf9.net内容
autostart = False
eghostios = true
sparsemem = True
[localhost]
port = 7200
udp = 11000
workingdir = ..\tmp\
`3640`
image = ..\IOS\unzip-c3640-ik9o3s-mz.124-10.bin
model = 3640
idlepc = 0x605c9218
exec_area = 64
confreg = 0x2142
# mmap = False
ram = 256
slot0 = NM-1E
slot1 = NM-4T
`router R1`
model = 3640
console = 3001
exec_area = 64
e0/0 = SW 1
S1/0 = FR1 1
s1/1 = R3 S1/2
`router R2`
console = 3002
model = 3640
exec_area = 64
e0/0 = SW 3
s1/0 = FR1 2
S1/1 = R3 S1/3
`router R3`
console = 3003
model = 3640
exec_area = 64
`router R4`
console = 3004
model = 3640
exec_area = 64
E0/0 = SW 2
`router R5`
console = 3005
model = 3640
exec_area = 64
E0/0 = SW 4
`ethsw SW`
1 = access 2 #VLAN A
2 = access 2
3 = access 3 #VLAN B
4 = access 3
`FRSW FR1`
1:102 = 2:201
设备配置
R1上的最终配置
R2上的最终配置
R3上的最终配置
R4上的最终配置
R5上的最终配置
检查路由
没有配置虚拟链路前
用Show ip ospf neighbor 来显示OSPF 邻居
检查各个设备路由情况
这时如果帧中继链路故障，则会出现两个area 0,在R4上PING不通R5上E0/0的IP地址，在R5上PING不通R4上E0/0的IP。
R1上没有25.0.0.0/8网络的路由。
R2上没有14.0.0.0/8网络的路由.
R1和R2都属于ABR，连接area 0 和area 1，虚拟链路总是建立在ABR路由器之间。在每一台ABR路由器的OSPF配置通过area virtual-link命令来配置，指定虚拟链路要穿过的区域和这条链路远端的ABR路由器router-id。
配置虚拟链路之后 R1和R2路由表中注意标记框类的路由，接口表示：R1 为OSPV_VL1
R2为 OSPF_VL2。
虚拟链路的类型为POINT_TO_POINT。
