Question:
(a) What is the main security vulnerability of IPv4?
(b) Which protocol can be used for secure remote login?
(c) Distinguish between the transport and tunnel mode in IPSec.
(d) Why does the Authentication Header (AH) not authenticate the user of an application?
(e) Name two VPN protocols. Explain how tunneling is used for building Virtual Private Networks. What are the disadvantages of using tunneling?