拓扑：
内部服务器配置：
interface FastEthernet0/0
ip address 192.168.1.1 255.255.255.0
duplex auto
speed auto
!
router ospf 100
router-id 1.1.1.1
log-adjacency-changes
network 192.168.1.0 0.0.0.255 area 0
中心一配置：
crypto isakmp policy 10
authentication pre-share
crypto isakmp key cisco address 0.0.0.0 0.0.0.0
crypto isakmp keepalive 10 periodic
crypto ipsec transform-set trans esp-des esp-md5-hmac
crypto ipsec profile dmvpn-profile
set transform-set trans
interface Tunnel2
bandwidth 1000
ip address 172.16.1.2 255.255.255.0
no ip redirects
ip mtu 1400
ip nhrp map multicast dynamic
ip nhrp map 172.16.1.3 10.1.1.3
ip nhrp map multicast 10.1.1.3
ip nhrp network-id 100
ip nhrp holdtime 3600
ip nhrp cache non-authoritative
ip tcp adjust-mss 1360
ip ospf network broadcast
ip ospf cost 100
ip ospf priority 2
delay 1000
tunnel source FastEthernet0/1
tunnel mode gre multipoint
tunnel key 12345
tunnel protection ipsec profile dmvpn-profile
ip address 192.168.1.2 255.255.255.0
interface FastEthernet0/1
ip address 10.1.1.2 255.255.255.0
router-id 2.2.2.2
network 172.16.1.0 0.0.0.255 area 0
中心二配置：
interface Tunnel3
ip address 172.16.1.3 255.255.255.0
ip nhrp map 172.16.1.2 10.1.1.2
ip nhrp map multicast 10.1.1.2
ip ospf cost 105
ip address 192.168.1.3 255.255.255.0
ip address 10.1.1.3 255.255.255.0
router-id 3.3.3.3
分支一：
interface Loopback0
ip address 4.4.4.4 255.255.255.0
interface Tunnel4
ip address 172.16.1.4 255.255.255.0
ip nhrp nhs 172.16.1.2
ip nhrp nhs 172.16.1.3
ip ospf priority 0
ip address 10.1.1.4 255.255.255.0
router-id 4.4.4.4
network 4.4.4.0 0.0.0.255 area 0
分支二配置：
ip address 5.5.5.5 255.255.255.0
interface Tunnel5
ip address 172.16.1.5 255.255.255.0
ip address 10.1.1.5 255.255.255.0
router-id 5.5.5.5
network 5.5.5.0 0.0.0.255 area 0
验证：