全网初始使用的路由协议为EIGRP，现要求全网启用OSPF，实现EIGRP到OSPF的平滑过度。但R2 R3的1.1.23.0/24网段仍使用EIGRP。
初始配置
R1
conf t
int l 0
ip ad 1.1.1.1 255.255.255.0
int s 0
ip ad 1.1.11.1 255.255.255.0
encap f
no arp f
no frame inv
frame map ip 1.1.11.2 102 b
frame map ip 1.1.11.3 103 b
no shut
int s 1
ip ad 1.1.14.1 255.255.255.0
no shut
router eigrp 1
net 1.0.0.0
end
R2
conf t
int l 0
ip ad 1.1.2.2 255.255.255.0
int s 0
ip ad 1.1.11.2 255.255.255.0
encap f
no arp f
no frame inv
frame map ip 1.1.11.1 201 b
frame map ip 1.1.11.3 201 b
no shut
int s 1
ip ad 1.1.23.2 255.255.255.0
router eigrp 1
net 1.0.0.0
end
R3
ocnf t
int l 0
ip ad 1.1.3.3 255.255.255.0
int s0
ip ad 1.1.11.3 255.255.255.0
encap f
no arp f
no frame inver
frame map ip 1.1.11.1 301 b
frame map ip 1.1.11.2 301 b
no shut
int s 1
ip ad 1.1.23.3 255.255.255.0
clock rate 64000
no shut
router eigrp 1
net 1.0.0.0
end
R4
conf t
int l 0
ip ad 1.1.4.4 255.255.255.0
int s 1
ip ad 1.1.14.4 255.255.255.0
clock rate 64000
no shut
router eigrp 1
net 1.0.0.0
end
这时各个路由器上的路由表状态为
R1#sh ip route
1.0.0.0/24 is subnetted, 7 subnets
C 1.1.1.0 is directly connected, Loopback0
D 1.1.2.0 [90/2297856] via 1.1.11.2, 00:02:10, Serial0
D 1.1.3.0 [90/2297856] via 1.1.11.3, 00:02:10, Serial0
D 1.1.4.0 [90/2297856] via 1.1.14.4, 00:02:06, Serial1
C 1.1.11.0 is directly connected, Serial0
C 1.1.14.0 is directly connected, Serial1
D 1.1.23.0 [90/2681856] via 1.1.11.3, 00:02:10, Serial0
[90/2681856] via 1.1.11.2, 00:02:10, Serial0
R2#sh ip route
1.0.0.0/24 is subnetted, 7 subnets
D 1.1.1.0 [90/2297856] via 1.1.11.1, 00:02:25, Serial0
C 1.1.2.0 is directly connected, Loopback0
D 1.1.3.0 [90/2297856] via 1.1.23.3, 00:03:00, Serial1
D 1.1.4.0 [90/2809856] via 1.1.11.1, 00:02:25, Serial0
C 1.1.11.0 is directly connected, Serial0
D 1.1.14.0 [90/2681856] via 1.1.11.1, 00:02:25, Serial0
C 1.1.23.0 is directly connected, Serial1
R3#sh ip route
1.0.0.0/24 is subnetted, 7 subnets
D 1.1.1.0 [90/2297856] via 1.1.11.1, 00:02:37, Serial0
D 1.1.2.0 [90/2297856] via 1.1.23.2, 00:03:11, Serial1
C 1.1.3.0 is directly connected, Loopback0
D 1.1.4.0 [90/2809856] via 1.1.11.1, 00:02:37, Serial0
C 1.1.11.0 is directly connected, Serial0
D 1.1.14.0 [90/2681856] via 1.1.11.1, 00:02:37, Serial0
C 1.1.23.0 is directly connected, Serial1
R4#sh ip route
1.0.0.0/24 is subnetted, 7 subnets
D 1.1.1.0 [90/2297856] via 1.1.14.1, 00:03:16, Serial1
D 1.1.2.0 [90/2809856] via 1.1.14.1, 00:03:01, Serial1
D 1.1.3.0 [90/2809856] via 1.1.14.1, 00:03:01, Serial1
C 1.1.4.0 is directly connected, Loopback0
D 1.1.11.0 [90/2681856] via 1.1.14.1, 00:03:16, Serial1
C 1.1.14.0 is directly connected, Serial1
D 1.1.23.0 [90/3193856] via 1.1.14.1, 00:03:01, Serial1
第一步：在R1R2 R3R4上启用OSPF
R1
conf t
int l 0
ip ospf net point-to-point
router ospf 1
net 1.1.1.1 0.0.0.0 a 0
net 1.1.11.1 0.0.0.0 a 0
net 1.1.14.1 0.0.0.0 a 0
end
R2
conf t
int l 0
ip ospf net point-to-point
int s 0
ip ospf p 0
router ospf 1
net 1.1.2.2 0.0.0.0 a 0
net 1.1.11.2 0.0.0.0 a 0
nei 1.1.11.1
end
R3
conf t
int l 0
ip ospf net point-to-point
int s 0
ip ospf p 0
router ospf 1
net 1.1.3.3 0.0.0.0 a 0
net 1.1.11.3 0.0.0.0 a 0
nei 1.1.11.1
end
R4
conf t
int l 0
ip ospf net point-to-poin
router ospf 1
net 1.1.14.4 0.0.0.0 a 0
net 1.1.4.4 0.0.0.0 a 0
end
这时，查看路由表状态和初始是一样的，因为EIGRP（internal)的AD为90，OSPF的AD为110。
第五步：修改剩余EIGRP的配置
R2
conf t
router eigrp 1
no au
net 1.1.23.2 0.0.0.0
no net 1.0.0.0
end
R3
conf t
router eigrp 1
no au
net 1.1.23.3 0.0.0.0
no net 1.0.0.0
end
到此，路由的平滑过渡完成，现在路由器上路由表的状态
R4#sh ip route
1.0.0.0/24 is subnetted, 7 subnets
O 1.1.1.0 [110/65] via 1.1.14.1, 00:07:35, Serial1
O 1.1.2.0 [110/129] via 1.1.14.1, 00:07:35, Serial1
O 1.1.3.0 [110/129] via 1.1.14.1, 00:07:35, Serial1
C 1.1.4.0 is directly connected, Loopback0
O 1.1.11.0 [110/128] via 1.1.14.1, 00:07:35, Serial1
C 1.1.14.0 is directly connected, Serial1
O E1 1.1.23.0 [110/228] via 1.1.14.1, 00:04:52, Serial1
