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7/27/2019 networksecurityslideshare-120315150406-phpapp01

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Presentation On

NETWORK SECURITY

PRESENTED BY:-

MISS.PALLAVI SONONE.

(Branch-CSE.)

PLIT, Buldana


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What is network security? Network security is preventing attackers from achieving

objectives through unauthorized access or unauthorized

use of computers and networks.

Basic Security Measures The basic security measures for computer systems fall into

four categories:

External security:- Protection from environmentaldamage.

Surveillance:- Proper placement of security cameras candeter theft

Auditing:- Creating a computer or paper audit can helpdetect wrongdoing

Viruses/worms:- Many different types of viruses, such asparasitic, boot sector, stealth, polymorphic, and macro.


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What is a firewall?

Used to control the flow of traffic (both inflows

and outflows, but primarily inflows) betweennetworks

The connected networks can be internal or a

combination of internal and external networks

Firewalls

A system or combination of systems that

supports an access control policy between twonetworks.

A firewall can limit the types of transactions

that enter a system, as well as the types of

transactions that leave a system.


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Characteristics of Good Firewalls

All traffic from inside the

corporate network to outside

the network, and vice-versa,

must pass through it;

Only authorized traffic, as

defined by the security policy, is

allowed to pass through it; and

the system itself is immune topenetration.


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Firewalls 2 types

Apacket filterfirewall is essentially a router that has been

programmed to filter out or allow to pass certain IP addresses or

TCP port numbers.Aproxy serveris a more advanced firewall that acts as a

doorman into a corporate network. Any external transaction

that request something from the corporate network must enter

through the proxy server.

Proxy servers are more advanced but make external accesses

slower.


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Components of Firewalls

Chokes - limit the flow of packets between

networks. Read packets and determine,

based on the rules, if the traffic should pass

Gates - act as a control point for external

connections. They control the external

connections.


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GATECHOKE

DEFAULT

DENY

Application Level

Filtering Rule -

Deny everything except

Telnet & FTP

PACKETS

FTPFTPTELN

ET

Corporate

Internal

Network

SMTP HTTP SMTP

Rejected Packets


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Firewall Functions

Packet Filtering Network Address

Translation

Application-level Proxies

Stateful InspectionVirtual Private Networks

Real-time Monitoring


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Hence we conclude that NETWORK SECURITY

prevents attackers from achieving the objectives throughunauthorized access.

Firewall is very useful to provide the security inNETWORKING.


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