R1通过R4获取上游路由。
R2通过R5获取上游路由。

配置操作如下：
R1:
interface FastEthernet0/0
 ip address 13.1.1.1 255.255.255.0
router ospf 1
 network 13.1.1.0 0.0.0.255 area 0

R2:
interface FastEthernet0/1
 ip address 23.1.1.2 255.255.255.0
router ospf 1
 network 23.1.1.0 0.0.0.255 area 0

R3:
interface FastEthernet0/0
 ip address 13.1.1.3 255.255.255.0
 ip policy route-map r1
interface FastEthernet0/1
 ip address 23.1.1.3 255.255.255.0
 ip policy route-map r2
interface FastEthernet1/0
 ip address 34.1.1.3 255.255.255.0
interface FastEthernet1/1
 ip address 35.1.1.3 255.255.255.0
router ospf 1
 network 13.1.1.0 0.0.0.255 area 0
 network 23.1.1.0 0.0.0.255 area 0
 network 34.1.1.0 0.0.0.255 area 0
 network 35.1.1.0 0.0.0.255 area 0
access-list 1 permit 13.1.1.0 0.0.0.255
access-list 2 permit 23.1.1.0 0.0.0.255
route-map r1 permit 10
 match ip address 1
 set ip precedence priority
 set ip next-hop 34.1.1.4
route-map r2 permit 10
 match ip address 2
 set ip precedence critical
 set ip next-hop 35.1.1.5

R4:
interface FastEthernet0/0
 ip address 45.1.1.4 255.255.255.0
interface FastEthernet0/1
 ip address 34.1.1.4 255.255.255.0
router ospf 1
 network 34.1.1.0 0.0.0.255 area 0
 network 45.1.1.0 0.0.0.255 area 0

R5:
interface FastEthernet0/0
 ip address 45.1.1.5 255.255.255.0
interface FastEthernet0/1
 ip address 35.1.1.5 255.255.255.0
router ospf 1
 network 35.1.1.0 0.0.0.255 area 0
 network 45.1.1.0 0.0.0.255 area 0


R1#traceroute 45.1.1.5

Type escape sequence to abort.
Tracing the route to 45.1.1.5

  1 13.1.1.3 28 msec 12 msec 12 msec
  2 34.1.1.4 32 msec 32 msec 48 msec
  3 45.1.1.5 44 msec 56 msec 48 msec

R2#traceroute 45.1.1.4

Type escape sequence to abort.
Tracing the route to 45.1.1.4

  1 23.1.1.3 16 msec 12 msec 12 msec
  2 35.1.1.5 40 msec 36 msec 32 msec
  3 45.1.1.4 40 msec 32 msec 24 msec