12. Conclusion

Since 1998, when the first IPsec-related standards appeared, the protocol suite has evolved considerably, making the IKE management protocol more robust and simpler, and gradually integrating the mobile dimension of terminals.

Initially, this suite was confined to VPN services between a closed set of clearly identified entities. It was therefore possible to pre-configure the terminals and firewalls concerned, facilitating the implementation of IPsec security.

Other solutions then appeared, such as SSL and SSHv2 VPNs ("tunneling" and "port forwarding" services), and came to compete with IPsec VPNs for remote access only, with IPsec VPNs remaining the only secure VPN solution available today for interconnecting private networks.

The use of IPsec is tending to diversify, with the possibility of securing IPv6 mobility...