02-15-2022 06:28 AM - edited 02-15-2022 06:29 AM
I'm trying to create a encrypted tunnel use GRE over IPSec, but I am unable to get it to work. I believe I'm messing up my ip routes and getting them confused. My tunnels work before I try to encrypt them, but when I attempt to do it, I can no longer ping them anymore. The IP routes on the routers below are fine, I haven't left tin my attempt at doing them.
In case it's needed, the whole network is 10.100.0.0/19
This is a screenshot of it currently.
Carlow Router:
Building configuration... Current configuration : 2572 bytes ! version 15.1 no service timestamps log datetime msec no service timestamps debug datetime msec no service password-encryption ! hostname Carlow_Router ! ! ! ! ! ! ! ! ip cef no ipv6 cef ! ! ! ! license udi pid CISCO2911/K9 sn FTX1524693Y- license boot module c2900 technology-package securityk9 ! ! ! crypto isakmp policy 102 encr aes authentication pre-share group 5 ! crypto isakmp key cisco address 149.153.1.6 ! ! ! crypto ipsec transform-set CarlowBelfast_Set esp-aes esp-sha-hmac ! crypto map CarlowBelfast_Map 102 ipsec-isakmp set peer 149.153.1.6 set transform-set CarlowBelfast_Set match address 102 ! ! ! ! ! ! spanning-tree mode pvst ! ! ! ! ! ! interface Loopback0 ip address 1.1.1.1 255.255.255.255 ! interface Tunnel0 ip address 172.16.250.1 255.255.255.252 mtu 1476 tunnel source Serial0/0/0 tunnel destination 149.153.1.6 ! ! interface GigabitEthernet0/0 no ip address ip nat inside duplex auto speed auto ! interface GigabitEthernet0/0.10 encapsulation dot1Q 10 ip address 10.100.0.1 255.255.255.128 ip nat inside ! interface GigabitEthernet0/0.20 encapsulation dot1Q 20 ip address 10.100.0.129 255.255.255.224 ip nat inside ! interface GigabitEthernet0/0.30 encapsulation dot1Q 30 ip address 10.100.0.161 255.255.255.224 ip nat inside ! interface GigabitEthernet0/0.40 encapsulation dot1Q 40 ip address 10.100.0.193 255.255.255.224 ip nat inside ! interface GigabitEthernet0/0.50 encapsulation dot1Q 50 ip address 10.100.0.225 255.255.255.224 ip nat inside ! interface GigabitEthernet0/0.60 encapsulation dot1Q 60 ip address 10.100.1.1 255.255.255.240 ip nat inside ! interface GigabitEthernet0/0.70 encapsulation dot1Q 70 ip address 10.100.1.17 255.255.255.248 ip nat inside ! interface GigabitEthernet0/1 no ip address duplex auto speed auto shutdown ! interface GigabitEthernet0/2 no ip address duplex auto speed auto shutdown ! interface Serial0/0/0 ip address 149.153.1.2 255.255.255.252 crypto map CarlowBelfast_Map ! interface Serial0/0/1 no ip address clock rate 2000000 shutdown ! interface Vlan1 no ip address shutdown ! router ospf 1 router-id 1.1.1.1 log-adjacency-changes network 10.100.0.0 0.0.255.255 area 1 network 149.153.1.4 0.0.0.3 area 1 network 149.153.1.0 0.0.0.3 area 1 ! router ospf 2 log-adjacency-changes network 172.16.250.0 0.0.0.3 area 2 ! ip classless ip route 0.0.0.0 0.0.0.0 149.153.1.1 ! ip flow-export version 9 ! ! access-list 102 permit ip 10.100.0.0 0.0.255.255 10.100.0.0 0.0.255.255 ! ! ! ! ! ! line con 0 ! line aux 0 ! line vty 0 4 login ! ! ! end
Belfast Router:
Building configuration... Current configuration : 2479 bytes ! version 15.1 no service timestamps log datetime msec no service timestamps debug datetime msec no service password-encryption ! hostname Belfast_Router ! ! ! ! ! ! ! ! ip cef no ipv6 cef ! ! ! ! license udi pid CISCO2911/K9 sn FTX15247LB2- license boot module c2900 technology-package securityk9 ! ! ! crypto isakmp policy 102 encr aes authentication pre-share group 5 ! crypto isakmp key cisco address 149.153.1.2 ! ! ! crypto ipsec transform-set BelfastCarlow_Set esp-aes esp-sha-hmac ! crypto map BelfastCarlow_Map 102 ipsec-isakmp set peer 149.153.1.2 set transform-set BelfastCarlow_Set match address 102 ! ! ! ! ! ! spanning-tree mode pvst ! ! ! ! ! ! interface Loopback0 ip address 3.3.3.3 255.255.255.255 ! interface Tunnel0 ip address 172.16.250.2 255.255.255.252 mtu 1476 tunnel source Serial0/0/1 tunnel destination 149.153.1.2 ! ! interface GigabitEthernet0/0 no ip address ip nat inside duplex auto speed auto ! interface GigabitEthernet0/0.10 encapsulation dot1Q 10 ip address 10.100.2.1 255.255.255.224 ip nat inside ! interface GigabitEthernet0/0.20 encapsulation dot1Q 20 ip address 10.100.2.33 255.255.255.224 ip nat inside ! interface GigabitEthernet0/0.30 encapsulation dot1Q 30 ip address 10.100.2.65 255.255.255.224 ip nat inside ! interface GigabitEthernet0/0.40 encapsulation dot1Q 40 ip address 10.100.2.97 255.255.255.240 ip nat inside ! interface GigabitEthernet0/0.50 encapsulation dot1Q 50 ip address 10.100.2.113 255.255.255.248 ip nat inside ! interface GigabitEthernet0/0.60 encapsulation dot1Q 60 ip address 10.100.2.121 255.255.255.248 ip nat inside ! interface GigabitEthernet0/1 no ip address duplex auto speed auto shutdown ! interface GigabitEthernet0/2 no ip address duplex auto speed auto shutdown ! interface Serial0/0/0 no ip address clock rate 2000000 shutdown ! interface Serial0/0/1 ip address 149.153.1.6 255.255.255.252 clock rate 2000000 crypto map BelfastCarlow_Map ! interface Vlan1 no ip address shutdown ! router ospf 1 router-id 3.3.3.3 log-adjacency-changes network 10.100.0.0 0.0.255.255 area 1 network 149.153.1.4 0.0.0.3 area 1 network 149.153.1.0 0.0.0.3 area 1 ! router ospf 2 log-adjacency-changes network 172.16.250.0 0.0.0.3 area 2 ! ip classless ip route 0.0.0.0 0.0.0.0 149.153.1.5 ! ip flow-export version 9 ! ! access-list 102 permit ip 10.100.0.0 0.0.255.255 10.100.0.0 0.0.255.255 ! ! ! ! ! ! line con 0 ! line aux 0 ! line vty 0 4 login ! ! ! end
02-15-2022 11:55 AM
Hello,
I only have a minute to reply saw your post and thought i could help.
First of all i would opt for protecting the GRE tunnel with IPSEC all in the same configuration so anything that goes over the tunnel is encrypted.
Second of all for your issues looks like you are not accounting for the fact in the IPSEC crypto ACL that the traffic will be matching the GRE tunnel source <-> destination not the LAN traffic.
Regards
George
02-15-2022 12:09 PM
Hello,
if this is a Packet Tracer project, post the zipped project (.pkt) file...
02-15-2022 12:13 PM
02-15-2022 12:40 PM
Hello,
what instructions are you following ? You have legacy crypto maps, tunnel interfaces, OSPF, static routes and partial NAT all mixed up.
02-15-2022 01:30 PM
Hello,
in any case, the access lists for the crypto map are wrong. They need to be:
Carlow_Router
access-list 102 permit ip 10.100.0.0 0.0.0.255 10.100.2.0 0.0.0.255
Belfast_Router
access-list 102 permit ip 10.100.2.0 0.0.0.255 10.100.0.0 0.0.0.255
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