05-13-2019 06:06 AM - edited 02-21-2020 09:38 PM
Hello , the last 3 days i have been struggling with ipsec configuration on cisco routers here is my topology on gns 3
both sites can ping with each other but without encryption
this is the ipsec configuration
and whech i chek the ecryption i always got nothing with
#R2 show crypto isakmp sa
neither with
#R2 show crypto ipsec sa
( 0 pkt enc/dec )
Solved! Go to Solution.
05-13-2019 08:46 AM
05-13-2019 06:11 AM
05-13-2019 06:35 AM
I fixed the ACL but i still have the same issue with
show crypto ipsec sa
show crypto isakmp sa
05-13-2019 06:39 AM - edited 05-13-2019 06:51 AM
Please post the full configuration of both routers
Also enabled debugging "debug crypto isakmp" and upload the output of the debug
Are you generating some traffic in order to bring up the tunnel? The VPN will not establish until interesting traffic is generated.
05-13-2019 07:02 AM
R2 configuration:
R2(config)#int f0/0
R2(config-if)# ip address 10.10.10.1 255.255.255.0
R2(config-if)# no sh
R2(config-if)# ex
R2(config)#int f0/1
R2(config-if)# ip address 172.16.1.1 255.255.255.0
R2(config-if)# no sh
R2(config-if)# ex
R2(config)# ip route 0.0.0.0 0.0.0.0 10.10.10.2
R2(config)# crypto isakmp enable
R2(config)#crypto isakmp policy 20
R2(config-isakmp)#authentication pre-share
R2(config-isakmp)#encryption 3des
R2(config-isakmp)#hash md5
R2(config-isakmp)#group 1
R2(config-isakmp)#lifetime 3600
R2(config-isakmp)#exit
R2(config)#crypto isakmp key cisco123 address 11.11.11.1
R2(config)#crypto ipsec transform-set myset esp-3des esp-md5-hmac
R2(config)#acess-list 100 permit ip 172.16.1.0 0.0.0.255 192.168.10.0 0.0.0.255
R2(config)#crypto map mymap 20 ipsec-isakmp
R2(config-crypto-map)#set peer 11.11.11.1
R2(config-crypto-map)#set transform-set myset
R2(config-crypto-map)#exit
R2(config)#int f0/0
R2(config-if)# crypto map mymap
R3 configuration:
R3(config)#int f0/0
R3(config-if)# ip address 11.11.11.1 255.255.255.0
R3(config-if)# no sh
R3(config-if)# ex
R3(config)#int f0/1
R3(config-if)# ip address 192.168.10.1 255.255.255.0
R3(config-if)# no sh
R3(config-if)# ex
R3(config)# ip route 0.0.0.0 0.0.0.0 11.11.11.2
R3(config)# crypto isakmp enable
R3(config)#crypto isakmp policy 20
R3(config-isakmp)#authentication pre-share
R3(config-isakmp)#encryption 3des
R3(config-isakmp)#hash md5
R3(config-isakmp)#group 1
R3(config-isakmp)#lifetime 3600
R3(config-isakmp)#exit
R3(config)#crypto isakmp key cisco123 address 10.10.10.1
R3(config)#crypto ipsec transform-set myset esp-3des esp-md5-hmac
R3(config)#acess-list 100 permit ip 192.168.10.0 0.0.0.255 172.16.1.0 0.0.0.255
R3(config)#crypto map mymap 20 ipsec-isakmp
R3(config-crypto-map)#set peer 10.10.10.1
R3(config-crypto-map)#set transform-set myset
R3(config-crypto-map)#exit
R3(config)#int f0/0
R3(config-if)# crypto map mymap
debug isn't working i got this everytime i try
05-13-2019 07:16 AM
05-13-2019 07:43 AM - edited 05-13-2019 07:43 AM
even after i pinged R2 to R3 nothing changed still got the same issue and i dont think the problem is related to no exchaged traffic because i think the IKE phase 1 isn't established yet since this command show no active SA
05-13-2019 07:58 AM
05-13-2019 08:05 AM
yeah each router ping the other
but how can i check about the NAT config ?
05-13-2019 08:08 AM
05-13-2019 08:17 AM
R1 configuration
R2(config)#int f0/0
R2(config-if)# ip address 10.10.10.2 255.255.255.0
R2(config-if)# no sh
R2(config-if)# ex
R2(config)#int f0/1
R2(config-if)# ip address 11.11.11.2 255.255.255.0
R2(config-if)# no sh
R2(config-if)# ex
R2(config)# ip route 172.16.1.0 255.255.255.0 10.10.10.1
R2(config)# ip route 192.168.10.0 255.255.255.0 11.11.11.1
-------------------------------------------------------------------
R2 configuration
R2(config)#int f0/0
R2(config-if)# ip address 10.10.10.1 255.255.255.0
R2(config-if)# no sh
R2(config-if)# ex
R2(config)#int f0/1
R2(config-if)# ip address 172.16.1.1 255.255.255.0
R2(config-if)# no sh
R2(config-if)# ex
R2(config)# ip route 0.0.0.0 0.0.0.0 10.10.10.2
R2(config)# crypto isakmp enable
R2(config)#crypto isakmp policy 20
R2(config-isakmp)#authentication pre-share
R2(config-isakmp)#encryption 3des
R2(config-isakmp)#hash md5
R2(config-isakmp)#group 1
R2(config-isakmp)#lifetime 3600
R2(config-isakmp)#exit
R2(config)#crypto isakmp key cisco123 address 11.11.11.1
R2(config)#crypto ipsec transform-set myset esp-3des esp-md5-hmac
R2(config)#acess-list 100 permit ip 172.16.1.0 0.0.0.255 192.168.10.0 0.0.0.255
R2(config)#crypto map mymap 20 ipsec-isakmp
R2(config-crypto-map)#set peer 11.11.11.1
R2(config-crypto-map)#set transform-set myset
R2(config-crypto-map)#exit
R2(config)#int f0/0
R2(config-if)# crypto map mymap
--------------------------------------------------------------
R3 configuration:
R3(config)#int f0/0
R3(config-if)# ip address 11.11.11.1 255.255.255.0
R3(config-if)# no sh
R3(config-if)# ex
R3(config)#int f0/1
R3(config-if)# ip address 192.168.10.1 255.255.255.0
R3(config-if)# no sh
R3(config-if)# ex
R3(config)# ip route 0.0.0.0 0.0.0.0 11.11.11.2
R3(config)# crypto isakmp enable
R3(config)#crypto isakmp policy 20
R3(config-isakmp)#authentication pre-share
R3(config-isakmp)#encryption 3des
R3(config-isakmp)#hash md5
R3(config-isakmp)#group 1
R3(config-isakmp)#lifetime 3600
R3(config-isakmp)#exit
R3(config)#crypto isakmp key cisco123 address 10.10.10.1
R3(config)#crypto ipsec transform-set myset esp-3des esp-md5-hmac
R3(config)#acess-list 100 permit ip 192.168.10.0 0.0.0.255 172.16.1.0 0.0.0.255
R3(config)#crypto map mymap 20 ipsec-isakmp
R3(config-crypto-map)#set peer 10.10.10.1
R3(config-crypto-map)#set transform-set myset
R3(config-crypto-map)#exit
R3(config)#int f0/0
R3(config-if)# crypto map mymap
05-13-2019 08:23 AM
05-13-2019 08:29 AM
i forget to write "match address 100" here in this post but i did included it on R2 and R3 crypto map settings as u can see from this ss
05-13-2019 08:32 AM
05-13-2019 08:39 AM
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