V. PROTOCOL IMPLEMENTATION
IPSec can be implemented on the end hosts or in the gateways/routers or in both. Where in the network IPSec is deployed depends on the security requirements of the users [3].
Using the Open Source software GNS3 that simulates networks and with the Use of open Packet Analysing software Wireshark I’m creating a Site to Site virtual network and using IPsec to provide encryption between two sites (Routers) of the company and watch the behaviour of packets as data in it gets encapsulated by IPSec.
The Network includes:
3 Cisco routers running the c3600 ios: One of the routers serving as the internet cloud and two others serving as different company sites namely London and Northampton.
Two Different networks (London and Northampton) with two public IP addresses on their interfaces. They also have a loopback interface each for testing the connections between the networks.
The network runs the Open Short First Path (OSPF) routing protocol. The aim is to create an IPSec configuration between the London and Northampton Offices.
An ISAKMP Policy has to be created on both the London and Northampton Routers. This Policy consists of
Authentication: pre-shared-key
IKE Encryption: AES 256
IKE Hashing: SHA
IKE key exchange with Diffie-Hellman Group: Group 5
IKE Lifetime: 3600