Explain the seven layers of the OSI model in detail.
At which layers do packet-filtering routers and firewalls reside?
How do packet-filtering routers and firewalls protect a network?
Include at least one reference.© BrainMass Inc. brainmass.com March 21, 2019, 7:07 pm ad1c9bdddf
Internet is mainly a packet switched network. It works on TCP and UDP. The packets that are transmitted over the network may be captured by any machine. So the information sent over the internet is visible to all, and hence not secure in direct form. So we need to find some methodology to hide this information from the outside world. This is called network security. Hence, Network security is the study of techniques that can allow us secure transfer of information over a communication network or communication channel. The following points needs to be considered while we discuss network security: -
• Confidentiality: - only the sender and receiver of information must be able to understand the contents of the transmitted message.
• Authentication: - both sender and receiver must be able to confirm the identity of the other party involved in communication.
• Message integrity and non-repudiation: - the contents of the message received should not be altered on the way, i.e. a malicious user should not be corrupting the message and forwarding them.
• Availability and access control: - the machines over the network must be properly available to the correct user, i.e. prevention of DoS (denial of service) attacks and blocking unauthenticated access.
OSI Network Model: -
The Open System Interaction Reference model or the OSI ...
The expert explains the seven layers of the OSI model. Which layers packet-filtering routers and firewalls reside are determined.