(a) At what layer does IPsec operate?
(b) What layers does IPsec protect?
(c) Compare the amount of cryptographic security in IPsec with that in SSL/TLS.
(d) Compare centralized management in IPsec and SSL/TLS.
(e) Why is IPsec's transparent protection attractive compared with SSL/TLS' non-transparent protection?
(f) Which versions of IP can use IPsec?