Case Learning: using VTI to solve the problem of dynamic IP Interconnection between Branch offices and headquarters

Requirements: the branch office (R1) has only ADSL lines and needs to exchange LAN visits with the headquarters (R3).

= R3murHQ =

Crypto keyring PSK

Pre-shared-key address 0.0.0.0 0.0.0.0 key cisco

Crypto ipsec transform-set TS esp-3des esp-sha-hmac

!

Crypto ipsec profile VTI

Set transform-set TS

Crypto isakmp profile DVTI

Keyring PSK

Match identity address 0.0.0.0

Virtual-template 1

Interface Virtual-Template1 type tunnel

Ip unnumbered Loopback0

Tunnel mode ipsec ipv4

Tunnel protection ipsec profile VTI

Interface Loopback0

Ip address 192.168.1.3 255.255.255.0

!

!

Interface Loopback100

Ip address 10.23.0.3 255.255.255.0

!

Interface GigabitEthernet0/0

Ip address 100.23.0.3 255.255.255.0

!

!

Router ospf 1

Network 10.23.0.0 0.0.0.255 area 0

Network 192.168.1.0 0.0.0.255 area 0

Ip route 0.0.0.0 0.0.0.0 100.23.0.2

= R1murBranch =

Crypto keyring PSK

Pre-shared-key address 0.0.0.0 0.0.0.0 key cisco

!

!

Crypto ipsec transform-set TS esp-3des esp-sha-hmac

!

Crypto ipsec profile VTI

Set transform-set TS

!

Interface Loopback0

Ip address 192.168.1.1 255.255.255.0

!

!

Interface Loopback100

Ip address 10.12.0.1 255.255.255.0

!

!

Interface Tunnel1

Ip unnumbered Loopback0

Tunnel source GigabitEthernet0/0

Tunnel mode ipsec ipv4

Tunnel destination 100.23.0.3

Tunnel protection ipsec profile VTI

!

Interface GigabitEthernet0/0

Ip address 100.12.0.1 255.255.255.0

!

Router ospf 1

Network 10.12.0.0 0.0.0.255 area 0

Network 192.168.1.0 0.0.0.255 area 0

!

Ip route 0.0.0.0 0.0.0.0 100.12.0.2