Transcript Week 8 Powerpoint

NT2580 Introduction to
Information Security
Unit 8
Networks and Communications and
their Inherent Weaknesses
© ITT Educational Services, Inc. All rights reserved.
Learning Objective
Explain the importance of network principles
and architecture to security operations.
NT2580 Introduction to Information Security
© ITT Educational Services, Inc. All rights reserved.
Page 2
Key Concepts
 Open Systems Interconnection (OSI)
network model and its security lapses
 Physical and logical network topologies
 Characteristics of a secure network
 802.11 WLAN technology weaknesses,
vulnerabilities, and mitigation strategies
 Internet Protocol version 4 (IPv4) and
Internet Protocol version 6 (IPv6) and their
use in IT infrastructures for secure
communications
NT2580 Introduction to Information Security
© ITT Educational Services, Inc. All rights reserved.
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EXPLORE: CONCEPTS
NT2580 Introduction to Information Security
© ITT Educational Services, Inc. All rights reserved.
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OSI Network Model
 The seven-layer OSI reference
model organizes protocols and services
in levels of ordered operations.
 The protocol stack or network stack
refers to layered network protocols in the
OSI model.
 Lower-level protocols encapsulate
higher-level protocols as they descend
the protocol stack.
NT2580 Introduction to Information Security
© ITT Educational Services, Inc. All rights reserved.
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TCP/IP Explained
 Internet Protocol (IP) packets contain source
addresses and destination addresses to transmit
data.
 IP resides at the lower levels and encapsulates
upper-layer packets to send them across the
network.
 Transmission Control Protocol (TCP) builds
reliable connection-oriented transmissions.
 IP encapsulates TCP to connect sources with
destinations using certain ports and a specific
service protocol.
NT2580 Introduction to Information Security
© ITT Educational Services, Inc. All rights reserved.
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TCP/IP is Insecure
 It was designed in early 1980s as an open
standard.
 It was created before security was an issue.
Common issues with TCP/IP:
 TCP SYN attack
 IP spoofing
 Sequence guessing
 Source routing
 Connection hijacking
NT2580 Introduction to Information Security
© ITT Educational Services, Inc. All rights reserved.
Page 7
Insecure vs. Secure Application
Layer Protocols
Insecure Protocol
Secure Protocol
File Transfer Protocol (FTP) Secure File Transfer
Protocol (SFTP)
Hypertext Transfer Protocol Secure Hypertext Transfer
(HTTP)
Protocol (HTTPS)
Telnet
Simple Network
Management Protocol
(SNMP) v1/2
NT2580 Introduction to Information Security
Secure Shell (SSH)
SNMPv3
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Encapsulation
NT2580 Introduction to Information Security
© ITT Educational Services, Inc. All rights reserved.
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Topologies
 Network topology: The arrangement or
hierarchy of networked devices
NT2580 Introduction to Information Security
© ITT Educational Services, Inc. All rights reserved.
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Network Topology
Considerations
 It can help enforce security policies.
 Isolated segments for development and
production servers and user groups
compartmentalize risk.
 Security protocols help protect
confidentiality and integrity.
NT2580 Introduction to Information Security
© ITT Educational Services, Inc. All rights reserved.
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WLANs
 Institute of Electrical and Electronics
Engineers (IEEE) 802.11 a/b/g/n
NT2580 Introduction to Information Security
© ITT Educational Services, Inc. All rights reserved.
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EXPLORE: PROCESSES
NT2580 Introduction to Information Security
© ITT Educational Services, Inc. All rights reserved.
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Network Security Components
 Routers
 Switches
 Dual-homed
hosts
 Tunneling
NT2580 Introduction to Information Security
© ITT Educational Services, Inc. All rights reserved.
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Securing Network Environments
 Harden network
 Use non-routable addresses
 Isolate users in defined
domains and/or separate
groups
NT2580 Introduction to Information Security
© ITT Educational Services, Inc. All rights reserved.
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Remote Access and Wireless
User Considerations
 Isolate wireless users from wired
users.
 Separate remote user groups from
local user groups.
NT2580 Introduction to Information Security
© ITT Educational Services, Inc. All rights reserved.
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Summary
 The seven-layer OSI reference
model organizes protocols and services
in levels of ordered operations.
 TCP/IP is inherently insecure–use alternate
secure protocols.
 A topology is a representation of how
devices and systems interconnect.
 Network security components include
routers, switches, dual-homed hosts, and
tunneling.
NT2580 Introduction to Information Security
© ITT Educational Services, Inc. All rights reserved.
Page 17