GNS3 配置Static p2p GRE over IPsec

1、實驗拓撲

2、基礎網絡配置

R1配置：

interface FastEthernet0/0

 ip address 12.1.1.1 255.255.255.0

interface FastEthernet1/0

 ip address 13.1.1.1 255.255.255.0

R2配置：

interface FastEthernet0/0

 ip address 12.1.1.2 255.255.255.0

interface FastEthernet1/0

 ip address 172.16.1.254 255.255.255.0

ip route 0.0.0.0 0.0.0.0 12.1.1.1

R3配置：

interface FastEthernet0/0

 ip address 13.1.1.3 255.255.255.0

interface FastEthernet1/0

 ip address 192.168.1.254 255.255.255.0

ip route 0.0.0.0 0.0.0.0 13.1.1.1

R4配置：

interface FastEthernet0/0

 ip address 172.16.1.1 255.255.255.0

ip route 0.0.0.0 0.0.0.0 172.16.1.254

R5配置:

interface FastEthernet0/0

 ip address 192.168.1.1 255.255.255.0

ip route 0.0.0.0 0.0.0.0 192.168.1.254

3、配置Static p2p GRE over IPsec

3.1、配置GRE

R2配置：

interface Tunnel2

 ip address 1.1.1.1 255.255.255.0

 tunnel source 12.1.1.2

 tunnel destination 13.1.1.3

R3配置：

interface Tunnel3

 ip address 1.1.1.2 255.255.255.0

 tunnel source 13.1.1.3

 tunnel destination 12.1.1.2

3.2、配置LAN-TO-LAN ×××（此時的ACL與普通的LAN-TO-LAN ×××有差異）

R2配置：

crypto isakmp policy 1

 encr 3des

 authentication pre-share

 group 2

crypto isakmp key cisco123 address 13.1.1.3

crypto ipsec transform-set ccie esp-3des esp-sha-hmac 

access-list 100 permit gre host 12.1.1.2 host 13.1.1.3

crypto map mymap 1 ipsec-isakmp 

 set peer 13.1.1.3

 set transform-set ccie 

 match address 100

interface FastEthernet0/0

 crypto map mymap

R3配置：

crypto isakmp policy 1

 encr 3des

 authentication pre-share

 group 2

crypto isakmp key cisco123 address 12.1.1.2

crypto ipsec transform-set ccie esp-3des esp-sha-hmac 

access-list 100 permit gre host 13.1.1.3 host 12.1.1.2

crypto map mymap 1 ipsec-isakmp 

 set peer 12.1.1.2

 set transform-set ccie 

 match address 100

interface FastEthernet0/0

 crypto map mymap

3.3、配置動態路由協議（此時私網流量走的都是隧道。）

R2配置：

router ospf 1

 network 1.1.1.0 0.0.0.255 area 0

 network 172.16.1.0 0.0.0.255 area 0

R3配置：

router ospf 1

 network 1.1.1.0 0.0.0.255 area 0

 network 192.168.1.0 0.0.0.255 area 0

4、NAT對Static p2p GRE over IPsec的影響

通過上面得知，內網流量走的都是GRE隧道，所以，當NAT應用在物理口時對Static p2p GRE over IPsec是沒有影響的。但當NAT應用在Tunnel口時，必須將內網網段排除。