Network Security Questions

There are 10 multiple choice questions regarding basic network security. I had answered what I thought would be the correct answers. If I am incorrect, please offer the correct answer along with your comments as to why your answers are correct.

1. Why are computer networks so difficult to secure?

a. User Anonymity
b. Networks are complex, dynamic, and difficult to understand and verify
c. There are many points of attack, making it difficult to completely secur
d. All of the above

My answer is all of the above

2. Which of the following are shortcomings of most intrusion detection systems?
a. Their effectiveness is based upon where you put them in your network.
b. Too may false alarms can cause an operator to disbelieve bona fide attacks.
c. They need to be continually updated to recognize the latest attacks.
d. They are limited in their ability to detect intrusive activity within encrypted data packets/sessions.
e. All of the above

My anser is C.

3. An intrusion detection sensor and "sniffer" have this in common.
a. They evesdrop on all network data looking for patterns of interest
b. It is difficult to detect that either is running somewhere on the network
c. They collect and store network information
d. All of the above
e. None of the above

My Answer is A but I am not sure

4. I used my firewall rule table to filter out (deny) IP addresses of "bad guys". Am I safe?
a. Yes, because I can accurately determine the packet sender from the IP address
b. No, because the attacker can put a fictitious source IP his/her packet.
c. Not necessarily, because the attacker may use micro-fragmentation to prevent the firewall from assembling the entire packet and reading the important TCP/UDP port information.
d. All but (A)

5. My answer is C

When placing VPN hardware on your corporate network to harness the Internet, you should consider placing it:
a. Just inside of your wireless access point
b. It depends on the operational needs and security model of your company.
c. Just outside of your corporate firewall
d. So that your network intrusion detection system can only see encrypted packets transmitted by the VPN hardware.

I am not sure what a VPN is actually...

6. My company is located in three geographical locations and is connected via the Internet. I purchase one Class C network and then assign contiguous blocks of IP addresses (subnets) to each location. The Internet has the capability to route between my locations. Twenty years ago, this would not have been possible. This is possible mostly due to the introduction of:

a. TCP
b. Classless Internet Domain Routing (CIDR)
c. Encryption
d. Firewalls

My answer would be d however I am confusing it with TCP.

7. The process of adding headers and trailers to an application data packet prior to transport over a network is called:

a. Encapsulation
b. Sequencing
c. Fragmentation
d. Complication

My answer would be a.

8.To securely encrypt data between company branch offices, using the public Internet as the communication network, I would use:

a. QoS Encryption
b. Link Encryption
c. A VPN
d. A firewall

My guess would be d.

9.I entered 'www.cybercrime.com' in my web browser and the web site comes up on my computer. How did the computer find this web server's IP address?

a. Domain Name Services (DNS)
b. Address Resolution Protocol (ARP)
c. Border Gateway Protocol (BGP)
d. Dynamic Host Configuration Protocol (DHCP)

My answer would be a.

10.Computers really communicate using their hardware (MAC) addresses. What service performs the translation between a computer's MAC and IP addresses?

a. Domain Name Services (DNS)
b. Border Gateway Protocol (BGP)
c. Dynamic Host Configuration Protocol (DHCP)
d. Address Resolution Protocol (ARP)

My answer would be b but I am confusing this with a.