What is VPN? Virtual Private Network (VPN) creates a secure network connection over a public network such as the internet. It allows devices to exchange data through a secure virtual tunnel. It uses a combination of security features like encryption, authentication, tunneling protocols, and data integrity to provide secure communication between participating peers. What is Authentication, Confidentiality & Integrity? Authentication - Verifies that the packet received is actually from the claimed sender. It verifies the authenticity of sender. Pre-shared Key, Digital Certificate are some methods that can be used for authentication. Integrity - Ensures that the contents of the packet has not been altered in between by man-in-middle. Hashing Algorithm includes MD5, SHA. Confidentiality - Encrypts the message content through encryption so that data is not disclosed to unauthorized parties. Encryption algorithms include DES (Data Encryption Standard), 3DES (Triple-DES), AES (Ad
What is a Firewall? Firewall is a device that is placed between a trusted and an untrusted network. It deny or permit traffic that enters or leaves network based on pre-configured policies. Firewalls protect inside networks from unauthorized access by users on an outside network. A firewall can also protect inside networks from each other. For example - By keeping a Management network separate from a user network. What is the difference between Gateway and Firewall? A Gateway joins two networks together and a network firewall protects a network against unauthorized incoming or outgoing access. Network firewalls may be hardware devices or software programs. Firewalls works at which Layers? Firewalls work at layer 3, 4 & 7. What is the difference between Stateful & Stateless Firewall? Stateful firewall - A Stateful firewall is aware of the connections that pass through it. It adds and maintains information about users connections in state table, re