Network Security

1
Network Security

• Keeping your office network and computers secure
  from outside threats

2
Network Security Agenda/Overview

• Why do I need network security?
• What kinds of computers and networks should be
  secured?
• How do I secure my computer or network?
• Glossary of Terms
• References

3
Network Security

• Why do I need network security?

4
Network Security Why to secure

• Threats to your computer can occur in many ways,
  but they can be boiled down to
• Threats originating from within (inside your
  office/network)
• Threats originating from without (outside of your
  office/network)

5
Network Security Why to secure

• Threats originating from within can consist of
• Theft of files/info/equipment
• Malicious or accidental deletion of files
• Abuse of email/Internet access
• Power failures and surges
• Hardware failures
• And so on

6
Network Security Why to secure

• Although there are steps you can take to help
  avoid these threats from within, that is not the
  focus of this presentation

7
Network Security Why to secure

• This presentation will focus on threats that
  originate from the outside. These can include
• Viruses sent via email
• Identity theft
• Use of your computer in a Denial of Service (DoS)
  attack
• Accessing info stored on your hard drive

8
Network Security Why to secure

• Using your computer to forge emails
• Maliciously deleting files or changing data
• Monitoring your activity on the Internet
• Accessing back doors and Remote Administration
  to get into your computer
• And so on

9
Network Security Why to secure

• Any time a computer is connected to the Internet,
  it becomes vulnerable to these outside threats
• Even if a computer does NOT connect to the
  Internet, it is still vulnerable to getting a
  virus from a floppy disk or another computer that
  DOES connect to the Internet

10
Network Security

• What kinds of computers and networks need to be
  secured?
• We will look at several different configurations
  that are typical of small offices

11
Network Security What to secure

• Single or Multiple Computers no Internet
  connectivity
• Possible Threat Virus from a floppy disk or a CD
  made from a computer that is infected
• Additional Threat Virus can migrate from
  infected computer to others on the network

12
Network Security What to secure

• Stand-alone computers may still become infected
  with a virus transferred through floppies and CDs

13
Network Security What to secure

• Viruses can infect additional computers that are
  on a common network

14
Network Security What to secure

• Single Computer with Dial-up Access to the
  Internet
• Possible Threat Intruders from outside can
  possibly break in while computer is on-line
• Additional Threat Since the computer is on-line,
  viruses can also come in from email

15
Network Security What to secure

• Even with just dial-up service to the Internet, a
  hacker can gain access to your computer while it
  is on-line
• Also faces threats from email-based viruses

16
Network Security What to secure

• Single or Multiple Computers with Broadband
  Access to the Internet
• Possible Threat With broadband connections,
  computers are connected to Internet whenever they
  are on, so attacks from hackers are more likely
• Additional Threat Email-based viruses are still
  a problem

17
Network Security What to secure

• A computer connected to the Internet with a cable
  or DSL modem is most vulnerable to intruders
• Since it is always attached to the Internet, it
  gives hackers many opportunities to attempt to
  break into it

18
Network Security What to secure

• Multiple computers usually must use a ROUTER to
  connect through a cable or DSL modem. This offers
  some protection against intruders

19
Network Security What to secure

• In summary, whether you have
• Just one computer or many
• Stand-alone or networked
• Connected to the Internet or not
• Dial-up or broadband
• You need to secure your computers!

20
Network Security

• How do I secure my computer or network?
• We will look at several different products, both
  hardware and software, that protect different
  aspects of a computer or a network

21
Network Security How to secure

• There are many products available that help to
  secure an individual computer or a whole network
• There are also some common sense things you can
  do to help keep intruders out and your data safe

22
Network Security How to secure

• To protect against viruses
• Use a good Anti-Virus software package on all of
  your computers
• You MUST keep it updated with the latest virus
  definitions (requires Internet access)

23
Network Security How to secure

• To protect against viruses (cont.)
• Practice Common Sense email usage
• Dont open file attachments without scanning them
  for viruses
• Dont open file attachments that are programs
• Dont open file attachments from questionable
  sources
• Dont forward email attachments or hoaxes before
  checking them out
• Scan floppies or home-made CDs before using them

24
Network Security How to secure

• To protect against outside attacks
• Check the Windows website for known security
  problems. Do not update your OS without checking
  with your billing software vendor! (requires
  Internet access)
• This will keep you posted on security holes that
  attackers like to exploit.

25
Network Security How to secure

• To protect against outside attacks
• For dial-up computers or a single computer
  connected via broadband, purchase or download a
  software Firewall (Zone Alarm, Check Point,
  BlackICE, etc.
• This protects the computer while it is connected
  to the Internet and blocks attackers from
  accessing your computer

26
Network Security How to secure
27
Network Security How to secure

• To protect against outside attacks
• For multiple computers connected via broadband,
  purchase a hardware Firewall router (Linksys,
  Netgear, D-Link, Cisco, WatchGuard, etc.)
• A software or hardware Firewall monitors and
  blocks incoming packets if it determines they are
  coming from an attacker

28
Network Security How to secure
29
Network Security How to secure

• Remember!
• Use Anti-Virus software and keep it updated
• Use a software or hardware firewall to protect
  your computer or network
• Practice common sense email usage
• Do not update your operating system unless your
  billing software vendor permits it.
• Backup your critical data regularly to CD-Rs, Zip
  disks, or streaming tape
• Store the backups off-site if possible

30
Network Security

• Glossary

31
Network Security Glossary

• Anti-Virus Software
• Software that runs on a computer designed to
  protect that computer from any suspicious files
  or programs that try to run that could harm the
  computer
• Anti-virus software is only as good as its virus
  definitions
• As new viruses are created, the anti-virus
  software must be updated in order to be able to
  keep protecting the computer

32
Network Security Glossary

• Broadband Connection
• Broadband is a general term used to refer to
  high-speed connections to the Internet
• Cable and DSL are two types of broadband
  connections that are much faster than a dial-up
  connection

33
Network Security Glossary

• Cable Internet Access
• Cable Internet access comes over the cable TV
  (CATV) lines
• A cable modem takes the signal off of the CATV
  line and converts it into Ethernet
• Cable is commonly considered a form of
  broadband connection to the Internet
• Continued

34
Network Security Glossary

• Cable Internet Access (cont.)
• Typically about 10 times faster than dial-up
  modems
• Your cable company becomes your Internet Service
  Provider (ISP)
• Not all cable providers offer Internet access

35
Network Security Glossary

• Dial-up Internet Access
• Dial-up Internet access uses a standard phone
  line to dial an Internet Service Provider (ISP)
• Dial-up access ties up the phone line while it is
  in use
• Typical connection speeds are around 40 to 50
  thousand bits per second (kbps)
• Dial-up access will use an internal or external
  dial-up modem

36
Network Security Glossary

• DSL Internet Access
• DSL stands for Digital Subscriber Line
• DSL Internet access comes over the standard phone
  line or a special dedicated phone line
• If it is over a standard phone line, it rides on
  top of the standard voice portion and does not
  interfere with incoming or outgoing calls
• Continued

37
Network Security Glossary

• DSL Internet Access (cont.)
• A DSL modem takes the signal off of the phone
  line and converts it into Ethernet
• DSL is commonly considered a form of broadband
  connection to the Internet
• Typically about 10 times faster than dial-up
  modems
• You must typically be within 2 to 3 miles of the
  central phone switch office to use DSL

38
Network Security Glossary

• Ethernet
• A standards-based method of attaching devices
  together so that they can communicate at a given
  data rate, forming a Local Area Network (LAN)
• The standard defines the type of cabling, how it
  connects to devices, and the speed at which the
  data travels

39
Network Security Glossary

• Firewalls
• Software Firewall specialized software running
  on a computer to protect a single computer
• Hardware Firewall a network device designed to
  protect one or more computers
• Firewalls monitor incoming data to determine if
  it was requested by the user or if it is
  originating from a hacker (not requested)

40
Network Security Glossary

• Internet Service Provider (ISP)
• The company responsible for providing access and
  services to the Internet for end users
• For Dial-up access this is the company your
  computer calls with a modem
• For Cable access this is typically the cable TV
  provider
• For DSL access this is typically the local
  phone company, but it doesnt have to be

41
Network Security Glossary

• Local Area Network (LAN)
• A group of computers within one office or
  building that are connected on a common Ethernet
  wiring segment

42
Network Security Glossary

• Virus
• A program designed to do something counter
  productive or destructive

43
Network Security Glossary

• Wide Area Network (WAN)
• Two or more LANs connected together, over a
  larger area, such as cities, states or countries

44
Network Security

• References

45
Network Security - References

• Reference URLs
• http//www.cert.org
• http//www.secinf.net
• http//www.mcafee.com
• http//www.symantec.com
• http//www.faqs.org/faqs/firewalls-faq/
• http//hoaxbusters.ciac.org
• http//www.f-secure.com
• http//www.clock.org/jss/glossary/

46
Network Security

• The End