Page 209 - Computer_Science_F5

Computer Science critical servers for several hours, denying Firewalls
service to all users. Various methods, A firewall is a system that prevents
such as UDP floods, TCP floods, and unauthorised access to or from a private
ICMP floods, can initiate these attacks. network. It examines each message
The primary goal of the attacker is to entering and leaving the network and
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overwhelm the victim and disrupt the
to pass through. It can be implemented
provided services. allows only those authorized messages
in hardware, software, or both. A firewall
Ways to secure network helps to keep your computer more secure.

The following measures are to be taken It restricts information that comes to your
computer from other computers, giving
to secure the network: you more control over the data on your
(a) A strong firewall and proxy are to be computer and providing a line of defence
used to keep unwanted people out. against people or programs.

(b) Use a Virtual Private Network
(VPN). Types of firewalls:

(c) A strong antivirus and Internet (a) Application gateways are the first
security software package should generation of firewalls, also known
be installed. as proxy gateways or application

(d) For authentication, use strong gateways, and provide application-
passwords and change them level control over network traffic
frequently, such as on a weekly or (b) Packet filtering is a technique
monthly basis. whereby routers have Access
Control Lists (ACLs) switched on.
(e) When using a wireless connection, By default, a router will pass all
use a strong password. traffic sent to it without any sort of

(f) Employees should be cautious restrictions.
about physical security. (c) Hybrid systems merge the security of

(g) Prepare a network analyser or the application layer gateways with
network monitor and use it when the flexibility and speed of packet
needed. filtering; some vendors have created

(h) Implementation of physical systems that use both principles.
security measures like closed- Importance of firewall
circuit television for entry areas
and restricted zones. (a) It allows only authorised access
inside a network,
(i) Security barriers to restrict the (b) It prevents insider attacks on critical
organisation’s perimeter. systems,

(j) Fire extinguishers can be used (c) A firewall acts as a barrier that
for fire-sensitive areas like server checks information coming from
rooms and security rooms. the Internet or a network and allows

200
for Advanced Secondary Schools

Computer Science Form 5.indd 200 23/07/2024 12:33