Practice IP Addressing Questions Now
Start a timed practice session focusing on IPv4 & IPv6 Addressing topics from the CCNA question bank.
Start CCNA Practice Quiz →CCNA IP Addressing Question Bank (14 Questions)
Browse all 14 practice questions covering IPv4 & IPv6 Addressing for the CCNA certification exam. Each question includes the full answer and a detailed explanation to help you understand the concepts.
- Question 1IP Connectivity
What is the broadcast address for the subnet 172.16.32.0/20?
Show Answer & Explanation
Correct Answer: BExplanation:/20 = 20 network bits, 12 host bits. 2^12 = 4096 addresses per subnet. 172.16.32.0 + 4096 addresses: third octet ranges 32-47 (16 values × 256 = 4096). Broadcast = last address = 172.16.47.255. Next subnet starts at 172.16.48.0.
- Question 2Network Fundamentals
A network administrator needs to create 14 subnets from the 172.16.0.0/16 network. What is the most efficient subnet mask to use?
Show Answer & Explanation
Correct Answer: BExplanation:Borrowing 4 bits from the host portion gives 2^4 = 16 subnets, which is the minimum to accommodate 14 subnets. /16 + 4 = /20.
- Question 3Network Fundamentals
How many usable host addresses are in a /28 subnet?
Show Answer & Explanation
Correct Answer: BExplanation:/28 = 4 host bits = 2^4 = 16 total addresses. Subtract 2 (network address + broadcast) = 14 usable host IPs. Quick formula: usable hosts = 2^(32-prefix) - 2. Example: /28 subnet 192.168.1.0/28 → hosts .1 through .14, broadcast .15.
- Question 4Network Fundamentals
What is the IPv6 link-local address prefix?
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Correct Answer: CExplanation:FE80::/10 is the link-local prefix. These addresses are auto-configured and not routable beyond the local link.
- Question 5Network Fundamentals
A company uses 192.168.1.0/24 and needs a subnet with exactly 30 usable host addresses. What subnet mask should be used?
Show Answer & Explanation
Correct Answer: BExplanation:/27 provides 2^5 - 2 = 30 usable host addresses. /26 gives 62 (too many), /28 gives 14 (too few).
- Question 6Network Fundamentals
Which IPv4 address class provides the default subnet mask 255.255.0.0?
Show Answer & Explanation
Correct Answer: BExplanation:Class B (128.0.0.0–191.255.255.255) has a default mask of 255.255.0.0 (/16). Class A uses /8, Class C uses /24.
- Question 7IP Connectivity
What is VLSM (Variable-Length Subnet Masking) and why is it useful?
Show Answer & Explanation
Correct Answer: BExplanation:VLSM allows different subnets to have different prefix lengths: /24 for a 200-host LAN, /30 for point-to-point links (2 hosts), /28 for a 14-host segment. This prevents IP address waste compared to classful subnetting. Requires classless routing protocols (OSPF, EIGRP, BGP).
- Question 8Network Fundamentals
Which IPv6 address type is equivalent to a public IPv4 address?
Show Answer & Explanation
Correct Answer: CExplanation:Global unicast addresses (2000::/3) are globally routable and equivalent to public IPv4 addresses.
- Question 9IP Connectivity
What is the dual-stack approach to IPv4-to-IPv6 transition?
Show Answer & Explanation
Correct Answer: BExplanation:Dual-stack: interfaces have both IPv4 and IPv6 addresses. DNS returns A (IPv4) and AAAA (IPv6) records. Applications use whichever version is available (prefer IPv6). This allows gradual migration without breaking existing IPv4 services. Most common transition strategy.
- Question 10Network Fundamentals
A network engineer needs to assign IP addresses to devices on a /27 subnet. How many usable host addresses are available?
Show Answer & Explanation
Correct Answer: BExplanation:A /27 subnet has 5 host bits, giving 2^5 = 32 total addresses. Subtracting the network address and broadcast address leaves 30 usable host addresses. A /28 gives 14, /26 gives 62, and 32 is the total address count including network and broadcast.
- Question 11Network Fundamentals
A network uses the address 172.16.10.0/24. Which of the following is the broadcast address for this subnet?
Show Answer & Explanation
Correct Answer: CExplanation:For a /24 subnet, the last octet provides 8 host bits. The broadcast address has all host bits set to 1, which is 172.16.10.255. The network address is 172.16.10.0 (all host bits 0), and the usable host range is 172.16.10.1 to 172.16.10.254.
- Question 12IP Services
A network administrator needs to forward DHCP broadcast requests across router interfaces to reach a DHCP server on a different subnet. Which feature should be configured?
Show Answer & Explanation
Correct Answer: BExplanation:The 'ip helper-address' command configures a router interface to forward UDP broadcast packets (including DHCP) as unicast to a specific server IP. This is also known as DHCP relay. Without this, DHCP broadcasts would not cross router boundaries since routers do not forward broadcasts by default.
- Question 13Network Fundamentals
Which IPv4 address class provides a default subnet mask of 255.255.0.0?
Show Answer & Explanation
Correct Answer: BExplanation:Class B addresses (128.0.0.0–191.255.255.255) have a default subnet mask of 255.255.0.0 (/16). Class A uses 255.0.0.0 (/8), Class C uses 255.255.255.0 (/24), and Class D (224.0.0.0–239.255.255.255) is reserved for multicast and does not use subnet masks.
- Question 14IP Connectivity
Which IPv6 address type is equivalent to a private IPv4 address and is not routable on the Internet?
Show Answer & Explanation
Correct Answer: BExplanation:Unique local addresses (FC00::/7, commonly FD00::/8) are the IPv6 equivalent of RFC 1918 private addresses — they are not routable on the Internet but can be routed within an organization. Link-local addresses (FE80::/10) are only valid on a single link. Global unicast addresses (2000::/3) are the IPv6 equivalent of public IPv4 addresses.
Key IP Addressing Concepts for CCNA
CCNA IP Addressing Exam Tips
IPv4 & IPv6 Addressing questions in CCNA are typically scenario-based. Focus on service-level decision making aligned to official exam objectives. Priority concepts: ipv4, ipv6, subnet, cidr, vlsm, subnetting.
What CCNA Expects
- Anchor your answer in select the most practical, secure, and scalable answer for the stated scenario.
- IP Addressing scenarios for CCNA are frequently mapped to Domain 1 (20%), Domain 3 (25%), so read the objective carefully before picking controls or architecture.
- Expect multi-service scenarios where IP Addressing interacts with IAM, networking, storage, or observability patterns rather than appearing as an isolated service question.
- When two options are both technically valid, prefer the choice that best aligns with the exam's operational scope (Associate) and managed-service best practices.
High-Value IP Addressing Concepts
- Know the core IP Addressing building blocks cold: ipv4, ipv6, subnet, cidr.
- Review the edge-case features and limits for vlsm, subnetting; these details are commonly used to differentiate answer choices.
- Practice service-integration reasoning: how IP Addressing pairs with Routing, DHCP, NAT in real deployment patterns.
- For CCNA, explain why the chosen IP Addressing design meets reliability, security, and cost expectations better than the alternatives.
Common CCNA Traps
- Watch for answers that partially solve the requirement but miss operational constraints.
- Questions in Network Fundamentals often include distractors that look correct for IP Addressing but violate least-privilege, durability, or availability requirements.
- Avoid picking options purely by feature name; validate data path, failure handling, and governance impact before answering.
- If the prompt hints at automation or repeatability, eliminate manual-only operational answers first.
Fast Review Checklist
- Can you compare at least two IP Addressing implementation paths and justify which one best fits the scenario?
- Can you map the chosen answer back to Network Fundamentals (20%) outcomes for CCNA?
- Can you explain security and access boundaries for IP Addressing without relying on default-open assumptions?
- Can you describe how IP Addressing integrates with Routing and DHCP during failure, scaling, and monitoring events?