Cisco CCNA IPv4 and IPv6 Addressing 5 — Questions and Answers
Question 1: What is the broadcast address for the subnet 10.10.20.0/28?
- 10.10.20.14
- 10.10.20.15 (Correct answer)
- 10.10.20.31
- 10.10.20.255
Correct answer: 10.10.20.15
A /28 has a block size of 16; starting at .0, the broadcast address is .0 + 16 – 1 = 10.10.20.15.
Question 2: Which type of IPv6 address is automatically configured on an interface and used for neighbor discovery and routing protocol traffic on the local link?
- Global unicast
- Unique local
- Link-local (Correct answer)
- Anycast
Correct answer: Link-local
Link-local addresses (FE80::/10) are auto-configured on every IPv6 interface and are used for local-link communication including NDP and routing protocol hellos.
Question 3: A company needs 10 subnets from 192.168.1.0/24 with at least 10 hosts each. Which prefix length meets both requirements?
- /25
- /26
- /27 (Correct answer)
- /28
Correct answer: /27
A /27 provides 32 subnets (2^5) from a /24 and 30 usable hosts each (2^3 – 2), satisfying both requirements.
Question 4: Which IPv6 address represents the loopback address?
- ::1 (Correct answer)
- FE80::1
- FF00::1
- ::0
Correct answer: ::1
::1 (expanded: 0000:0000:0000:0000:0000:0000:0000:0001) is the IPv6 loopback address, equivalent to 127.0.0.1 in IPv4.
Question 5: What is the maximum number of subnets created when borrowing 4 bits from the host portion of a classful Class C network?
- 14
- 16 (Correct answer)
- 30
- 8
Correct answer: 16
Borrowing 4 bits provides 2^4 = 16 subnets (all 16 are usable with classless/CIDR addressing).
Question 6: Which feature allows a single public IPv4 address to be shared by many private hosts simultaneously?
- VLSM
- CIDR
- NAT/PAT (Correct answer)
- SLAAC
Correct answer: NAT/PAT
NAT with Port Address Translation (PAT) maps many private IP addresses to a single public IP by tracking unique source port numbers.
Question 7: Which of the following correctly identifies the IPv6 address type FF05::2?
- Link-local multicast — all routers on local link
- Site-local multicast — all routers within the site (Correct answer)
- Global unicast — routable on the Internet
- Unique local — used within an organization
Correct answer: Site-local multicast — all routers within the site
FF05::2 is a site-scoped multicast address targeting all routers within the site (scope value 5 = site-local).
Cisco CCNA IPv4 and IPv6 Addressing 5
What is the broadcast address for the subnet 10.10.20.0/28?