Basic IPSEC VPN configuration

Download network topology

File Name: ipsec-vpn.pkt
File Size: 11 KB

 

Configuration

Paris router configuration

hostname PARIS
!
crypto isakmp policy 1
 encr aes
 authentication pre-share
 group 2
!
crypto isakmp key 0 address 172.16.1.2
!
crypto ipsec security-association lifetime seconds 86400
!
crypto ipsec transform-set SECUREWAN esp-aes esp-sha-hmac
!
crypto map IPSECWAN 100 ipsec-isakmp 
 set peer 172.16.1.2
 set pfs group2
 set security-association lifetime seconds 86400
 set transform-set SECUREWAN 
 match address SECURED-TRAFFIC
!
!
interface FastEthernet0/0
 ip address 10.0.1.1 255.255.255.0
 duplex auto
 speed auto
!
interface Serial0/0/0
 ip address 172.16.1.1 255.255.255.252
 encapsulation frame-relay
 frame-relay interface-dlci 100
 crypto map IPSECWAN
!
ip route 10.100.1.0 255.255.255.0 172.16.1.2 
!
!
ip access-list extended SECURED-TRAFFIC
 permit ip 10.0.0.0 0.255.255.255 10.0.0.0 0.255.255.255
!

 

New-York router configuration

hostname NEWYORK
!
!
crypto isakmp policy 1
 encr aes
 authentication pre-share
 group 2
!
crypto isakmp key 0 address 172.16.1.1
!
crypto ipsec security-association lifetime seconds 86400
!
crypto ipsec transform-set SECUREWAN esp-aes esp-sha-hmac
!
crypto map IPSECWAN 100 ipsec-isakmp 
 set peer 172.16.1.1
 set security-association lifetime seconds 86400
 set transform-set SECUREWAN

 

OSFP dynamic routing with GRE tunnel over IPSEC

The IPSEC ACL is modified to allow GRE traffic over the tunnel and to deny any unencrypted traffic on the WAN link

ip access-list extended SECURED-TRAFFIC
 permit ip 10.0.0.0 0.255.255.255 10.0.0.0 0.255.255.255
 permit ip any any
 permit gre 10.254.1.0 0.0.0.3 10.254.1.0 0.0.0.3


GRE tunnel configuration on Paris router

interface Tunnel0
 ip address 10.254.1.1 255.255.255.252
 tunnel source Serial0/0/0
 tunnel destination 172.16.1.2
 tunnel mode gre ip


GRE tunnel configuration on NewYork router

interface Tunnel0
 ip address 10.254.1.2 255.255.255.252
 tunnel source Serial0/0/0
 tunnel destination 172.16.1.1
 tunnel mode gre ip


OSPF configuration over the tunnel

router ospf 1
 log-adjacency-changes
 network 10.0.1.0 0.0.0.255 area 0
 network 10.254.1.0 0.0.0.3 area 0

 

File Attachment:

File Name: ipsec-vpn-gre.pkt
File Size: 11 KB