PAT (Port Address Translation) is a subtype of NAT that maps multiple private IP addresses to a single public IP address using different port numbers. It is the most common form of NAT used in home and business networks to allow multiple internal hosts to access the internet using one public IP address.
MTCNA Course Material – NAT Concepts:
“PAT (also known as NAT overload) allows multiple devices to share a single public IP address. It uses different port numbers to distinguish sessions.”
Cisco IOS NAT Configuration Guide:
“PAT translates multiple local IP addresses to one public IP address by assigning different port numbers to each session.”
Other options:
A: Generic term — not specific enough
B: Static NAT maps one private IP to one public IP
C: Dynamic NAT maps private IPs to a pool of public IPs, not one-to-many
Final Answer: DQUESTION NO: 149 [IPv6 – Addressing Standards]
How long is an IPv6 address?
A. 32 bits
B. 128 bytes
C. 64 bits
D. 128 bits
Answer: D
IPv6 addresses are 128 bits in length, represented as eight groups of four hexadecimal digits separated by colons (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334). This allows for a vastly larger address space compared to IPv4 (32 bits).
MTCNA Course Material – IPv6 Basics:
“An IPv6 address is 128 bits long, providing 3.4×10^38 possible addresses. It is written in hexadecimal format.”
René Meneses MTCNA Study Guide – IPv6 Addressing:
“IPv6 = 128 bits, not bytes. Address includes a 64-bit network prefix and 64-bit interface identifier.”
Other options:
A: 32 bits is IPv4
B: 128 bytes = 1024 bits — incorrect
C: 64 bits = only half of an IPv6 address
Final Answer: DQUESTION NO: 150 [IP Addressing – Subnetting]
How many usable IP addresses are there in a 23-bit (255.255.254.0) subnet?
A. 512
B. 510
C. 508
D. 254
Answer: B
A /23 subnet provides 2^9 = 512 total addresses.
Subtract 2 (network address + broadcast address)
512 – 2 = 510 usable IP addresses
MTCNA Course Material – Subnet Calculations:
“For any subnet, usable hosts = 2^(32 – subnet mask bits) – 2.”
René Meneses MTCNA Study Guide – IP Subnetting:
“/23 provides 512 total addresses; usable = 510 after subtracting network and broadcast.”
Option Breakdown:
A: Total addresses (512)
B:✔Usable addresses (510)
C: Incorrect (508 is for /23 minus 4 — not relevant here)
D: 254 is usable for /24
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