CompTIA Security+ Question I-6

Emily, the security administrator, must configure the corporate firewall to allow all public IP addresses on the internal interface of the firewall to be translated to one public IP address on the external interface of the same firewall. Which of the following should Emily configure?

A. PAT
B. NAP
C. DNAT
D. NAC

Answer: A

Explanation:
Port Address Translation (PAT), is an extension to network address translation (NAT) that permits multiple devices on a local area network (LAN) to be mapped to a single public IP address. The goal of PAT is to conserve IP addresses.

Most home networks use PAT. In such a scenario, the Internet Service Provider (ISP) assigns a single IP address to the home network’s router. When Computer X logs on the Internet, the router assigns the client a port number, which is appended to the internal IP address. This, in effect, gives Computer X a unique address. If Computer Z logs on the Internet at the same time, the router assigns it the same local IP address with a different port number. Although both computers are sharing the same public IP address and accessing the Internet at the same time, the router knows exactly which computer to send specific packets to because each computer has a unique internal address.

CompTIA Security+ Question B-98

Review the following diagram depicting communication between PC1 and PC2 on each side of a router. Analyze the network traffic logs which show communication between the two computers as captured by the computer with IP 10.2.2.10.
DIAGRAM
PC1 PC2
[192.168.1.30]——–[INSIDE 192.168.1.1 router OUTSIDE 10.2.2.1]———[10.2.2.10] LOGS
10:30:22, SRC 10.2.2.1:3030, DST 10.2.2.10:80, SYN
10:30:23, SRC 10.2.2.10:80, DST 10.2.2.1:3030, SYN/ACK
10:30:24, SRC 10.2.2.1:3030, DST 10.2.2.10:80, ACK
Given the above information, which of the following can be inferred about the above environment?

A. 192.168.1.30 is a web server.
B. The web server listens on a non-standard port.
C. The router filters port 80 traffic.
D. The router implements NAT.

Answer: D

Explanation:
Network address translation (NAT) allows you to share a connection to the public Internet via a single interface with a single public IP address. NAT maps the private addresses to the public address. In a typical configuration, a local network uses one of the designated “private” IP address subnets. A router on that network has a private address (192.168.1.1) in that address space, and is also connected to the Internet with a “public” address (10.2.2.1) assigned by an Internet service provider.

CompTIA Security+ Question A-36

Which of the following network design elements allows for many internal devices to share one public IP address?

A. DNAT
B. PAT
C. DNS
D. DMZ

Answer: B

Explanation:
Port Address Translation (PAT), is an extension to network address translation (NAT) that permits multiple devices on a local area network (LAN) to be mapped to a single public IP address. The goal of PAT is to conserve IP addresses.

Most home networks use PAT. In such a scenario, the Internet Service Provider (ISP) assigns a single IP address to the home network’s router. When Computer X logs on the Internet, the router assigns the client a port number, which is appended to the internal IP address. This, in effect, gives Computer X a unique address. If Computer Z logs on the Internet at the same time, the router assigns it the same local IP address with a different port number. Although both computers are sharing the same public IP address and accessing the Internet at the same time, the router knows exactly which computer to send specific packets to because each computer has a unique internal address.

CompTIA A+ Question G-33

A computer technician is installing a new wireless router for a small office. The office already has an internal device that assigns addresses to users. Which of the following functions needs to be disabled on the router to prevent conflicts?

A. DMZ capability
B. MAC filtering capability
C. Network Address Translation
D. DHCP server functionality

Correct Answer: D

Explanation:
DHCP automatically assigns IP address, subnet mask and default gateway to provide access to workstations. Disable DHCP server before installing a wireless router so that you can configure it without DHCP assigning IP addresses to other computers.