Cisco CCNA
15 free questions with worked answers, and 149 more in the full bank.
Free questions
A junior technician notices collisions on an interface connected to a legacy hub. Which duplex setting is most likely causing this issue?
1 mark · Easy
After replacing a PC, the switchport logs show a continuous flapping of MAC addresses. What is the most probable reason for this behavior?
3 marks · Medium
An engineer analyzes a packet capture and observes ARP replies arriving without corresponding ARP requests. This behavior is indicative of what process or attack?
4 marks · Hard
Users complain of slow performance. An interface shows late collisions and CRC errors. What is the standard troubleshooting step for this symptom?
3 marks · Medium
A router needs to forward a packet but its ARP cache is empty for the destination IP on a directly connected subnet. What does the router do next?
1 mark · Easy
A router has three routes to 10.1.1.0/24: an OSPF route, an EIGRP route, and a Static route. Which route will be installed in the routing table?
1 mark · Easy
A packet is destined for 192.168.1.130. The routing table has 192.168.1.0/24 (AD 110) and 192.168.1.128/26 (AD 120). Which path does the router choose?
3 marks · Medium
A technician configures a floating static route as a backup to an EIGRP learned route for branch office connectivity. What is the necessary configuration step?
4 marks · Hard
Looking at the `show ip route` output, you see a route marked with a "D". What routing protocol generated this entry?
3 marks · Medium
You need to route traffic to the internet but do not have a specific route in the routing table. What kind of route should be configured?
1 mark · Easy
An admin notices a routing loop forming between three routers running RIPv2. Which mechanism prevents routing loops by not advertising a route back on the interface it was learned from?
3 marks · Medium
A multi-access OSPF network needs to elect a DR and BDR. Which router attribute is evaluated first to determine the DR?
1 mark · Easy
Two OSPF routers are connected over a point-to-point link. One router is stuck in the EXSTART state. What is the most likely cause of this issue?
3 marks · Medium
A network architect is designing a multi-area OSPF network. What is the strict requirement regarding Area 0?
4 marks · Hard
A technician is analyzing OSPF LSAs. Which LSA type is used by an ABR to advertise routes between different areas?
3 marks · Medium
More Cisco CCNA questions (page 2 of 3)
Answers and explanations are in the full bank.
- A network administrator changes the OSPF reference bandwidth on a router to 10000. What is the purpose of this command? · 3 marks
- An interface shows input and output errors and the link is up. Which command should be inspected first to decide whether the cabling is at fault? · 3 marks
- A certification question asks about NAT overload. Which answer is correct? · 4 marks
- A certification question asks about northbound API. Which answer is correct? · 4 marks
- A technician is documenting multilayer switch. Which statement belongs in the notes? · 1 mark
- A technician is documenting native VLAN on an 802.1Q trunk. Which statement belongs in the notes? · 1 mark
- A technician is documenting static route administrative distance. Which statement belongs in the notes? · 1 mark
- A technician is documenting Network Time Protocol. Which statement belongs in the notes? · 3 marks
- A technician is documenting switch port security. Which statement belongs in the notes? · 3 marks
- A technician is documenting southbound API. Which statement belongs in the notes? · 3 marks
- During troubleshooting, which explanation of wireless access point is accurate? · 4 marks
- During troubleshooting, which explanation of show vlan brief is accurate? · 4 marks
- During troubleshooting, which explanation of OSPF administrative distance is accurate? · 3 marks
- During troubleshooting, which explanation of Domain Name System is accurate? · 3 marks
- During troubleshooting, which explanation of DHCP snooping is accurate? · 3 marks
- During troubleshooting, which explanation of REST API is accurate? · 4 marks
- During routine technical work, which statement about longest-prefix route matching should guide the technician? · 3 marks
- During routine technical work, which statement about a directly connected route on Cisco IOS should guide the technician? · 3 marks
- During routine technical work, which statement about a normal static route on Cisco IOS should guide the technician? · 3 marks
- During routine technical work, which statement about an OSPF route on Cisco IOS should guide the technician? · 3 marks
- During routine technical work, which statement about a switch access port should guide the technician? · 3 marks
- During routine technical work, which statement about an 802.1Q trunk native VLAN should guide the technician? · 3 marks
- During routine technical work, which statement about the STP root bridge should guide the technician? · 3 marks
- During routine technical work, which statement about an EtherChannel should guide the technician? · 3 marks
- During routine technical work, which statement about CDP should guide the technician? · 3 marks
- During routine technical work, which statement about LLDP should guide the technician? · 3 marks
- During routine technical work, which statement about the IPv4 10.0.0.0/8 block should guide the technician? · 3 marks
- During routine technical work, which statement about IPv6 link-local addressing on a Cisco interface should guide the technician? · 3 marks
- During routine technical work, which statement about SLAAC should guide the technician? · 3 marks
- During routine technical work, which statement about the ip helper-address command should guide the technician? · 3 marks
- During routine technical work, which statement about Cisco IOS NAT overload should guide the technician? · 3 marks
- During routine technical work, which statement about a standard IPv4 ACL should guide the technician? · 3 marks
- During routine technical work, which statement about an extended IPv4 ACL should guide the technician? · 3 marks
- During routine technical work, which statement about DHCP snooping should guide the technician? · 3 marks
- During routine technical work, which statement about a REST API using JSON should guide the technician? · 3 marks
- NIDA receives internet routing from two upstream providers. Which BGP attribute is used by policy to prefer one provider over the other when paths differ? · 3 marks
- A network engineer wants to reduce the BGP table size received from a provider. Which technique summarises internal prefixes before they are advertised outward? · 4 marks
- A default gateway on a subnet needs automatic backup so hosts survive a router failure without manual intervention. Which protocol provides that on a Cisco network? · 4 marks
- Which command shows the directly connected neighbours and their platform, model and interface on a Cisco switch? · 1 mark
- Which switch configuration feature prevents a user from moving their PC to a different access port and joining a more privileged VLAN? · 3 marks
- A large campus is split into separate OSPF areas so that a topology change in one area does not force every router to recompute. Which OSPF feature makes this possible? · 3 marks
- NIDA must converge the campus Layer 2 topology in under a second after a link failure. Which protocol provides fast convergence by using an alternate port per switch? · 3 marks
- A campus runs RSTP but a backup link stays blocked for an extended period instead of taking over when the primary fails. Which design choice most often explains this behaviour? · 4 marks
- An EIGRP network requires faster convergence and a lower administrative distance than OSPF while remaining proprietary to Cisco. Which distance vector protocol meets this requirement? · 3 marks
- A remote branch needs only a default route toward the data centre and should not receive internal campus prefixes. Which OSPF area type limits it to a default route while still allowing internal routers to reach it? · 4 marks
- A branch office runs OSPF over a broadband link with limited bandwidth and high latency. Which interface value should be adjusted so OSPF does not send excessive hellos and adjacency traffic? · 3 marks
- A route learned from EIGRP must be shared into OSPF, and the reverse is also required. Which control prevents routing loops caused by redistributed routes? · 4 marks
- Which EIGRP component is used to find a feasible successor and could otherwise cause a routing loop if it were not discarded? · 4 marks
- A certification question asks about extended IPv4 ACL. Which answer is correct? · 4 marks
- During a workshop assessment, the reported condition is: A Cisco interface displays administratively down and line protocol down. What change is required before Layer 1 troubleshooting can continue? · 1 mark
- During a workshop assessment, the reported condition is: A Cisco interface is up but its line protocol is down. What should be investigated? · 3 marks
- During a workshop assessment, the reported condition is: A routing table contains O 172.16.0.0/16 [110/20] via 10.0.0.2. What does 110 represent? · 1 mark
- During a workshop assessment, the reported condition is: A router can ping its directly connected neighbor but not a remote network, and no matching or default route exists. What is required? · 3 marks
- During a workshop assessment, the reported condition is: A VLAN exists in the design document but does not appear in show vlan brief on the access switch. What should be corrected? · 1 mark
- During a workshop assessment, the reported condition is: A VLAN is present on both switches but traffic does not cross their trunk because it is missing from the allowed list. What should be changed? · 3 marks
- During a workshop assessment, the reported condition is: Two switches report a native VLAN mismatch on their 802.1Q trunk. What is the correct response? · 1 mark
- During a workshop assessment, the reported condition is: The wrong access switch becomes STP root after a topology change. Which configuration most directly influences the preferred root? · 3 marks
- During a workshop assessment, the reported condition is: An endpoint-facing PortFast interface receives a BPDU from an unexpected switch. Which feature should protect the edge? · 1 mark
- During a workshop assessment, the reported condition is: Two links configured for EtherChannel do not bundle because one side is trunking and the other is an access link. What must be done? · 3 marks
- During a workshop assessment, the reported condition is: Hosts in different VLANs cannot communicate through a router-on-a-stick design, and the router's subinterface lacks 802.1Q encapsulation. What is missing? · 1 mark