Flashcards
Firewalls
Cards in this deck (12)
- 1What is a firewall and what are its 2 main purposes?Blocks unauthorised packets to/from a network.
Drops packets based on rules.
Does packet analysis and logging. - 2Where can a firewall be placed?Network or Host-based
- 3Give 2 limitations of firewalls1. Can be bypassed using tunnelling
2. Cannot protected against insider attacks - 4Give the 3 basic functions of a firewall1. Prevent inbound traffic accessing internal services
2. Block output traffic
3. NAT - 5Name the 4 types of firewalls1. Stateless Packet Filters
2. Stateful Packet Filters
3. Application Gateways
4. Proxies - 6What are packet filters?Rules which define packets to be dropped based upon source/destination IP/port
- 7Give 3 advantages of packet filters1. Simple
2. Low-level
3. High assurance - 8Give 2 limitations of packet filters1. Easy to misconfigure
2. Doesn't support higher level authentication schemes - 9Discuss stateful packet filtersThey understand protocol requests and replies.
Generates rules dynamically - 10Discuss application gatewaysAnalyses the application-layer protocol in use rather than the port
- 11Give the advantage and disadvantages of using a proxy server as a firewallAdvantage: More complex analysis of traffic (files, viruses)
Disadvantages:
1. Expensive (proxy per service)
2. Slow
3. Hard to configure - 12What does NAT do?Network Address Translation.
Prevents attacks on random ports by hiding internal IPs.
Makes host-based firewalls redundant if using NFW+NAT
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- Bachelors Degree Computer Science (Computer Security) Flashcards on Firewalls, created by Alex Neves on 24/05/2016.
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- Alex Neves
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