Cisco CCNA IP Connectivity & IP Services Certification Exam |
Comprehensive Question Bank & Detailed Rationales
2026/2027
Question 1
What is the default Administrative Distance (AD) of a static route
pointing to an exit interface or next-hop IP address in Cisco IOS?
A. 0
B. 1
C. 90
D. 110
Correct Answer: B. 1
Detailed Rationale: Connected routes have an AD of 0, static routes
have an AD of 1, EIGRP internal routes have an AD of 90, and OSPF has
an AD of 110.
Question 2
Which IPv4 address range is designated for private internets as defined
by RFC 1918 for the 172.16.0.0 network?
A. 172.16.0.0 - 172.16.255.255
B. 172.16.0.0 - 172.31.255.255
C. 172.0.0.0 - 172.255.255.255
D. 172.16.0.0 - 172.19.255.255
,Correct Answer: B. 172.16.0.0 - 172.31.255.255
Question 3
In OSPF, what is the default Hello timer interval on a broadcast network
segment (such as Ethernet)?
A. 5 seconds
B. 10 seconds
C. 30 seconds
D. 60 seconds
Correct Answer: B. 10 seconds
Question 4
What is the primary function of the ip helper-address command
configured on a router interface?
A. To act as a secondary DNS resolver.
B. To intercept broadcast DHCP request packets and forward them as
unicast packets to a remote DHCP server.
C. To load-balance traffic across multiple OSPF paths.
D. To translate private IP addresses to public IP addresses.
Correct Answer: B. To intercept broadcast DHCP request packets and
forward them as unicast packets to a remote DHCP server.
Question 5
What type of NAT translates an internal private source IP address to a
unique public IP address while also utilizing Layer 4 port numbers to
allow thousands of internal hosts to share a single public IP?
,A. Static NAT
B. Dynamic NAT (Pool without Overload)
C. NAT Overload (PAT / Port Address Translation)
D. Destination NAT
Correct Answer: C. NAT Overload (PAT / Port Address Translation)
Question 6
What is the prefix format for an IPv6 Global Unicast Address (GUA) as
defined by standard allocation guidelines?
A. 2000::/3
B. FE80::/10
C. FC00::/7
D. FF00::/8
Correct Answer: A. 2000::/3
Question 7
Where should an Extended Access Control List (ACL) ideally be placed
relative to the source of the traffic for optimal network efficiency?
A. As close to the destination as possible.
B. As close to the source of the traffic as possible to drop unwanted
packets early.
C. Only on the loopback interfaces of core routers.
D. Exclusively on Layer 2 switch access ports.
, Correct Answer: B. As close to the source of the traffic as possible to
drop unwanted packets early.
Question 8
How does a Cisco router select its OSPF Router ID (RID) automatically if
the router-id command is not explicitly configured?
A. The lowest IP address of any active physical interface.
B. The highest IP address configured on any active loopback interface; if
none exist, the highest IP address on an active physical interface.
C. The MAC address of the management interface converted to an IPv4
dotted-decimal string.
D. The first IP address assigned by a DHCP server.
Correct Answer: B. The highest IP address configured on any active
loopback interface; if none exist, the highest IP address on an active
physical interface.
Question 9
What is the purpose of configuring a Floating Static Route?
A. To load-balance traffic across two equal-cost paths.
B. To provide a backup path by assigning a higher Administrative
Distance than the primary dynamic routing protocol.
C. To automatically update IP addresses when DHCP fails.
D. To encrypt routing updates.
Correct Answer: B. To provide a backup path by assigning a higher
Administrative Distance than the primary dynamic routing protocol.
Comprehensive Question Bank & Detailed Rationales
2026/2027
Question 1
What is the default Administrative Distance (AD) of a static route
pointing to an exit interface or next-hop IP address in Cisco IOS?
A. 0
B. 1
C. 90
D. 110
Correct Answer: B. 1
Detailed Rationale: Connected routes have an AD of 0, static routes
have an AD of 1, EIGRP internal routes have an AD of 90, and OSPF has
an AD of 110.
Question 2
Which IPv4 address range is designated for private internets as defined
by RFC 1918 for the 172.16.0.0 network?
A. 172.16.0.0 - 172.16.255.255
B. 172.16.0.0 - 172.31.255.255
C. 172.0.0.0 - 172.255.255.255
D. 172.16.0.0 - 172.19.255.255
,Correct Answer: B. 172.16.0.0 - 172.31.255.255
Question 3
In OSPF, what is the default Hello timer interval on a broadcast network
segment (such as Ethernet)?
A. 5 seconds
B. 10 seconds
C. 30 seconds
D. 60 seconds
Correct Answer: B. 10 seconds
Question 4
What is the primary function of the ip helper-address command
configured on a router interface?
A. To act as a secondary DNS resolver.
B. To intercept broadcast DHCP request packets and forward them as
unicast packets to a remote DHCP server.
C. To load-balance traffic across multiple OSPF paths.
D. To translate private IP addresses to public IP addresses.
Correct Answer: B. To intercept broadcast DHCP request packets and
forward them as unicast packets to a remote DHCP server.
Question 5
What type of NAT translates an internal private source IP address to a
unique public IP address while also utilizing Layer 4 port numbers to
allow thousands of internal hosts to share a single public IP?
,A. Static NAT
B. Dynamic NAT (Pool without Overload)
C. NAT Overload (PAT / Port Address Translation)
D. Destination NAT
Correct Answer: C. NAT Overload (PAT / Port Address Translation)
Question 6
What is the prefix format for an IPv6 Global Unicast Address (GUA) as
defined by standard allocation guidelines?
A. 2000::/3
B. FE80::/10
C. FC00::/7
D. FF00::/8
Correct Answer: A. 2000::/3
Question 7
Where should an Extended Access Control List (ACL) ideally be placed
relative to the source of the traffic for optimal network efficiency?
A. As close to the destination as possible.
B. As close to the source of the traffic as possible to drop unwanted
packets early.
C. Only on the loopback interfaces of core routers.
D. Exclusively on Layer 2 switch access ports.
, Correct Answer: B. As close to the source of the traffic as possible to
drop unwanted packets early.
Question 8
How does a Cisco router select its OSPF Router ID (RID) automatically if
the router-id command is not explicitly configured?
A. The lowest IP address of any active physical interface.
B. The highest IP address configured on any active loopback interface; if
none exist, the highest IP address on an active physical interface.
C. The MAC address of the management interface converted to an IPv4
dotted-decimal string.
D. The first IP address assigned by a DHCP server.
Correct Answer: B. The highest IP address configured on any active
loopback interface; if none exist, the highest IP address on an active
physical interface.
Question 9
What is the purpose of configuring a Floating Static Route?
A. To load-balance traffic across two equal-cost paths.
B. To provide a backup path by assigning a higher Administrative
Distance than the primary dynamic routing protocol.
C. To automatically update IP addresses when DHCP fails.
D. To encrypt routing updates.
Correct Answer: B. To provide a backup path by assigning a higher
Administrative Distance than the primary dynamic routing protocol.
