I have been able to get the IPsec working in GNS3 with two Cisco 7200 routers. I use a router in the middle to simulate the ISP. I can pass traffic between the two LANS.

I have applied the same configuration to two real routers and I can't get traffic to pass. The tunnel shows up from both devices after attempting to send traffic.

Is this an issue with different platform or different versions of IOS. I can't make it work on real routers. I just put a router in the middle again to simulate an isp.

Here is the configuration I copy and paste into each router.

ROUTER 1 - cisco 2821 with 15.1 ios


crypto isakmp policy 1
encr 3des
hash md5
authentication pre-share
group 2
lifetime 86400
!
crypto isakmp key GbgcvA9TrpfJe9ja address 99.65.224.217
!
ip access-list extended VPN-TRAFFIC
permit ip host 10.1.2.57 192.168.55.0 0.0.0.255
!
crypto ipsec transform-set TS esp-3des esp-md5-hmac
!
crypto map CMAP 10 ipsec-isakmp
set peer 99.65.224.217
set transform-set TS
match address VPN-TRAFFIC
!
interface FastEthernet0/1
10.1.2.1 255.255.255.0
ip nat inside
no shut
!
interface FastEthernet0/0
ip address 110.50.101.212 255.255.252.0
ip nat outside
crypto map CMAP
no shut
!
ip nat inside source list 100 interface fastethernet0/0 overload
!
access-list 100 deny ip host 10.1.2.57 192.168.55.0 0.0.0.255
access-list 100 permit ip 10.1.2.0 0.0.0.255 any
!
ip route 0.0.0.0 0.0.0.0 110.50.100.1




ROUTER 2 - cisco 1841 with 12.4 ios


crypto isakmp policy 1
encr 3des
hash md5
authentication pre-share
group 2
lifetime 86400
!
crypto isakmp key GbgcvA9TrpfJe9ja address 110.50.101.212
!
ip access-list extended VPN-TRAFFIC
permit ip 192.168.55.0 0.0.0.255 host 10.1.2.57
!
crypto ipsec transform-set TS esp-3des esp-md5-hmac
!
crypto map CMAP 10 ipsec-isakmp
set peer 110.50.101.212
set transform-set TS
match address VPN-TRAFFIC
!
interface FastEthernet0/1
ip address 192.168.55.1 255.255.255.0
ip nat inside
no shut
!
interface FastEthernet0/0
ip address 99.65.224.217 255.255.252.0
ip nat outside
crypto map CMAP
no shut
!
ip nat inside source list 100 interface fastethernet0/0 overload
!
access-list 100 deny ip 192.168.55.0 0.0.0.255 host 10.1.2.57
access-list 100 permit ip 192.168.55.0 0.0.0.255 any
!
ip route 0.0.0.0 0.0.0.0 99.65.224.1