Question

Data Communication and Networking

1-->What are the three added fields when IPsec ESP is used? What do they surround in transport mode and tunnel mode for IPv4?

2-->How does IPsec provide a great deal of protection? Why do we focus on ESP and not on AH? What is tunneling? Which protects more of the original IP packet, transport mode or tunnel mode?

Answer 1

The three added field when IPsec ESP is uses are

1. Pad length field which is used to specify how much payload is padding rather than data.
2. The next header field which actually identifies the data carried.
3. The ESP authentication field it contains the integrity check value, which act as a digital signature.

The IPsec has two encryption modes: Transport modes and Tunnel mode as Tunnel mode encrypts the data portion of the packets that are leaving and transport mode is used to either gateway or host implementation and also provide protection for the upper layer protocols. The tunnel mode is more secured as compared to the transport mode.

2--> the IPsec protocol uses powerful encryption technologies which actually suite adds the security services to the IP layer in such a way that it is compatible with the IPv4 as well as the IPv6 technology.

Authentication Header is used to provide data integrity whereas ESP provides data confidentiality and thus making ESP more secured as compared to AH. The ESP uses more powerful encryption algorithm

Tunneling allows user to send all illegal IP addresses through the public network and tunneling also helps in hiding the actual source and the destination address over the internet.

The tunnel mode protects more of original ip packets