Network security Flashcards
(8 cards)
What is Network Security?
O In a distributed computer system such as a network, the protection covers resources that make up the network including:
communication channels and
devices such as, routers, bridges, switches, and servers
the files stored on those servers.
O Therefore, network security means preventing and/or detecting unauthorized access, use, alteration to these network resources
What is a Vulnerability?
A defect or weakness in network or system secmity procedures, design, implementation, or internal controls that can be exploited
and result in a secmity breach or violation of
secmit olic
What is a Zero-Day Vulnerability?
o It is a software vulnerability discovered be attackers before the vendor has become aware of
O Because the vendors are unaware, no patch exists for zero-day vulnerabiliiies, making attacks likely to succeed.
O The term “zero-day” refers to the fact that the vendor or developer has only iust learned of the flaw - which means they have “zero days” to fix it.
O A zero da attack takes place when hackers exploit the flaw before developers have a chance to address it.
What is Firewall?
What are the Functions of Firewall?
What is Firewall Security Policy?
Firewall Limitations?
A firewall is a hardware, software or a combination of both that monitors and filters network traffic ackets that attempt to either enter or leave the internal protected network.
The role of a firewall is to DENY or PERMIT access to a network based on the enforced Firewall Securit Policy.
Firewalls protect personal and corporate data stored on digital devices b blockin network-based unauthorized access.
What are the Functions of Firewall:3
1. A firewall inspects nemork traffic passing through it in both directions (i.e., inbound traffic and outbound traffic)
2. It Allows traffic specified in the firewall security policy, and Drops everything else
3. It performs Packet filtering, which is based on accept or deny policy specified in the firewall security policy.
What is Firewall Security Policy:
It is a collection of firewall rules that determine which types of network traffic the firewall accepts, and which are denied.
Firewall rules examine the control information (e.g., source and destination IPs) in each network acket and block or allow them based on the firewall rules.
Firewall rules specify:
source and destination IP addresses,
protocols (like TCP or UDP), and the
destination port numbers
Firewall Limitation:
Cannot protect against internal threats
e.g. fired System Administrator
Cannot ePectively protect against transfer of
virus-infected programs or files
because of heavy trafiic and huge range of file types
What is Network Port/ Service?
Network port:
It is a software-defined NUMBER associated with a network PROTOCOL that receives or transmits communicated data needed for a specific NETWORK SERVICE.
Network service:
Network services are applications running at the network layer and above (in the OSI reference model) that provide various functionalities to network users or other applications.
Common Network Port Numbers and Associated Protocols
Slide 15
Why are Network Ports Necessary?
What is NUm?
Num is 3
- A single computer can run multiple network
services.
- Network ports are necessary to allow the operatinq system to direct incominq and outqoinq network trafiic to the correct network service, such as WWW, EMAIL, and FTP.
- Without network ports, all network trafiic would arrive at the same IP address, and the computer wouldn’t know which service should handle it.
Explain three common Network Services
- World Wide Web (WWW): Provides access to websites and web applications using the HTTP/HTTPS protocols. Servers host web content, and clients (web browsers) request and display it.
- Email (Electronic Mail): Enables the sending, receiving, and storing of electronic messages using protocols like SMTP (for sending), POP3 (for receiving). Mail servers handle the storage and forwarding of emails, and email clients allow users to interact with their mailboxes.
- File Transfer Protocol (FTP): Facilitate the transfer of files between computers over a network. FTP servers host files, and FTP clients allow users to upload and download them.
