GRE over IPSEC ***

由于IPSEC ***不能支持组播和广播,因此不能运行动态路由协议,由于我们需要把一条***链路作为一条专线使用,还必须建立GRE tunnel隧道,以支持动态路由协议.

实验拓扑:



基本配置步骤如下:

1:配置基本路由和需保护流量的感兴趣访问列表(注意这里感兴趣流量设为GRE隧道流量)

2:配置GRE Tunnel隧道.

3:配置IPSEC ***.

4 :配置动态路由协议.

配置如下 :

R1#sho run

crypto isakmp policy 10

authentication pre-share

crypto isakmp key cisco address 202.1.1.2

!

crypto ipsec transform-set mytrans esp-3des

!

crypto map mymap 1 ipsec-isakmp

set peer 202.1.1.2

set transform-set mytrans

match address 101

!

interface Loopback0

ip address 10.1.1.1 255.255.255.0

!

interface Tunnel0

ip address 192.168.1.1 255.255.255.0

tunnel source Ethernet0/0

tunnel destination 202.1.1.2

!

interface Ethernet0/0

ip address 201.1.1.1 255.255.255.0

crypto map mymap

router ospf 1

log-adjacency-changes

network 10.1.1.0 0.0.0.255 area 0

network 192.168.1.0 0.0.0.255 area 0

ip route 0.0.0.0 0.0.0.0 Ethernet0/0

access-list 101 permit gre host 201.1.1.1 host 202.1.1.2

//注意访问列表所定义的IPSEC所保护的感兴趣流量为GRE流量.
R2#

interface Ethernet0/0

ip address 201.1.1.2 255.255.255.0

!

interface Ethernet2/0

ip address 202.1.1.1 255.255.255.0

R3#

crypto isakmp policy 10

authentication pre-share

crypto isakmp key cisco address 201.1.1.1

!

!

crypto ipsec transform-set mytrans esp-3des

!

crypto map mymap 10 ipsec-isakmp

set peer 201.1.1.1

set transform-set mytrans

match address 101

!

interface Loopback0

ip address 172.16.1.1 255.255.255.0

!

interface Tunnel0

ip address 192.168.1.2 255.255.255.0

tunnel source Ethernet2/0

tunnel destination 201.1.1.1

!

interface Ethernet2/0

ip address 202.1.1.2 255.255.255.0

half-duplex

crypto map mymap

!

router ospf 1

log-adjacency-changes

network 172.16.1.0 0.0.0.255 area 0

network 192.168.1.0 0.0.0.255 area 0

ip route 0.0.0.0 0.0.0.0 Ethernet2/0

!

access-list 101 permit gre host 202.1.1.2 host 201.1.1.1
测试:

R1#show ip os nei
Neighbor ID Pri State Dead Time Address Interface

172.16.1.1 0 FULL/ - 00:00:37 192.168.1.2 Tunnel0

R1#show ip route

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

E1 - OSPF external type 1, E2 - OSPF external type 2

i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

ia - IS-IS inter area, * - candidate default, U - per-user static route

o - ODR, P - periodic downloaded static route
Gateway of last resort is 0.0.0.0 to network 0.0.0.0
C 201.1.1.0/24 is directly connected, Ethernet0/0

172.16.0.0/32 is subnetted, 1 subnets

O 172.16.1.1 [110/11112] via 192.168.1.2, 00:41:22, Tunnel0

10.0.0.0/24 is subnetted, 1 subnets

C 10.1.1.0 is directly connected, Loopback0

C 192.168.1.0/24 is directly connected, Tunnel0

S* 0.0.0.0/0 is directly connected, Ethernet0/0

R1#show crypto isakmp sa

dst src state conn-id slot

202.1.1.2 201.1.1.1 QM_IDLE 8 0
R1#traceroute 172.16.1.1
Type escape sequence to abort.

Tracing the route to 172.16.1.1
1 192.168.1.2 132 msec * 156 msec //走的是隧道吧!

http://loguis.blog.51cto.com/635994/157510