Firewalls
By: Ryan Sternhagen
Review
Hardware or software used to block undesired network
communication
Usually used between the internet and an internal
network
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Uses for Hardware and Software Firewalls
Advantages/Disadvantages of each
Developments in their technologies
Hardware Firewalls
Firewalls implemented in hardware
At least 2 NICs for bidirectional transfer of data between
2 sources
Can be proprietary box or made using a standard PC
Many manufacturers of firewalls exist today offering a
wide variety of traffic handling capabilities and features
Cisco
Nokia
SonicWall
Symantec
Nortel
CyberGuard
Hardware Firewall Purpose
Utilizes hardware to quickly perform rules based
on default and user set configurations
Filters packets by address, protocol, ports,
stateful inspection
Other functions can include…
VPN gateways
Port/IP blocking
Intrusion Detection and Prevention
Encryption
Web caching
Activity logging and alerts
Advantages
Fast
No extra resources needed
Protects multiple PCs
Little configuration to be effective
Hides PCs from outside sources
Non-intrusive
Dedicated and secure platform
Stops traffic before it gets to the network
Disadvantages
Cost ($25,000)
Difficult to customize and update (firmware)
Ignores most outgoing traffic
Inconvenient for travelers
Potential bandwidth bottleneck
Cannot scale to growing needs well
Cannot stop infected PCs already in the network
Hardware Developments
More complex features are being implemented
on cheaper devices like protection from phishing
attacks and email scanning
Devices that automatically update themselves
for new threats
Motherboard chipsets like Nvidia’s Nforce 4
including capabilities that act like a co-processor
for the PC’s network handling
General increase in hardware performance
Software Firewalls
Firewalls implemented in software
Application level configuration
User controlled security for a specific PC
Software firewalls
ZoneAlarm
Norton Personal Firewall
McAfee Personal Firewall
Bullguard
Injoy Firewall
Software Firewall Purpose
Protects a PC from unauthorized access
Controls communication from particular
applications
Allows for feedback and notifications with user
Functions can include…
Port/Traffic Monitoring
Data Filtering
Email/File/Registry Protection
Intruder Alert
Network Time Restrictions
Individual User Configurations
Advantages
Highly scalable
Inexpensive (using ranging from $30-$80)
Works at the application level
Supports different user needs
Convenient for travel
Easy to update
Frequent updates
Interacts with user
Easy to monitor
Good for managing bandwidth
Disadvantages
Uses PC resources
Only protects the PC it’s installed on
Requires a lot of configuration to be effective
User can allow vulnerabilities
PC able to be seen by outside sources
Can be intrusive
Same vulnerabilities as OS
Can be passed or even disabled by malicious
code
Can conflict with some applications
Software Developments
Implementation into OS (SP2)
Better ISA firewalls
Spyware and Malware protection
Advanced features like security inspection
Conclusion
Hardware firewalls use ports and packet filtering
to get rid of unwanted network activity
Software firewalls operate at the application
level with input from the user as to what traffic is
okay
Both types have different ranges of features
which are directly related to their price
(hardware scales much larger)
A combination of both types of firewalls would
be the most effective option for all PC users
Sources
http://www.windowsecurity.com/articles/Comparing_Firewall_Featur
es.html
http://www.pcmag.com/article2/0,1895,1159158,00.asp
http://www.pcworld.com/news/article/0,aid,125269,00.asp
http://www.pcworld.com/news/article/0,aid,118213,00.asp
http://personal-firewall-software-review.toptenreviews.com/
http://www.isaserver.org/articles/2004tales.html
Questions?