There are eight network security questions. I have answered the questions however, I am unclear if I am correct. Please review and if I am wrong, please provide the correct answer along with your explanation.

1. Which of the following pieces of information can be found in the IP header?

a. Source address of the IP packet

b. Destination address for the IP packet

c. Sequence number of the IP packet

d. Both (A) and (B) only.

My answer is d.

2. We also don't want our undeliverable packets to hop around forever. What feature/flag limits the life of an IP packet on the network?

a. Time to Live counter

b. Subnet Mask

c. Header Checksum

d. Wackamole field

My answer is a.

3. I bank online. Which of the following are application-level encryption protocols that I would most likely use to securely bank online?

a. SSL and SET

b. Verisign and SHA1

c. READY, SET, and GO

d. PGP, PEM, and SSL

My answer is a.

4. We don't want our packets to get lost in transit. Which OSI layer is responsible for ordered delivery of packets?

a. Network

b. Link

c. Transport

d. Physical

my answer is b but I am not sure

5. When my teleconference data packets reach the destination computer, what information in the packet is used by the destination computer to figure out that the packets belong to the teleconferencing application?

a. Firewall rules

b. Port numbers in the TCP/UDP header

c. Three-way handshake initiated at the start of the communication.

d. IANA subnet class number in the first octet of the IP address

my answer would be c...but this is a far guess for me.

6. I want to request secure web pages using https://. What port will I need to open on my firewall to allow these SSL-encrypted packets to flow?

a. 161

b. 53

c. 6000

d. 443

e. 137

I thought for web pages uses port 80...

7. Based on what we have learned about TCP and UDP packet accounting mechanisms, which transport control protocol would I most likely use for Internet Telephony/Teleconferencing (Voice over IP)?

a. UDP - Because I don't want to retransmit if some of the packets get lost.

b. UDP - Because I want to make sure that no packets get lost.

c. TCP - Because I don't want to retransmit if some of the packets get lost.

d. TCP - Because I want to retransmit lost voice IP packets later on in the conversation.

I am not sure what they are asking

8. What is the standard IANA port number used for requesting web pages?

a. 80

b. 53

c. 21

d. 25

My answer is a.