You must configure and verify VLANs, trunks, IPv4/IPv6 addressing, default gateways, and static or OSPF routes, then troubleshoot with show commands. The single most important thing: confirm Layer 2 reachability and correct IP addressing before blaming routing or wireless.
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Domain overview
This domain covers the infrastructure and connectivity skills tested on CCNA 200-301 v2: switching and routing fundamentals, VLANs and trunking, IPv4/IPv6 addressing and configuration, static and dynamic routing, wireless access, and physical media selection. Questions are scenario-based, requiring you to diagnose faults, interpret show command output, and choose correct configuration or deployment options.
Exam objectives
VLAN creation, access port assignment, 802.1Q trunking, and inter-VLAN routing via SVIs or router subinterfaces
IPv4/IPv6 interface addressing, EUI-64, SLAAC, DHCP, DNS, and default gateway configuration on hosts
Static routes, OSPFv2/v3 neighbor adjacencies, and verifying the routing table with show ip route
Wireless 2.4/5 GHz behavior, channel overlap, and fiber versus copper media characteristics
Forgetting that a host needs both an IP address and a default gateway to reach other subnets, or misconfiguring DNS server addresses.
Assuming EUI-64 works without checking the interface MAC or that SLAAC alone provides DNS, when RDNSS or DHCPv6 may be required.
Treating trunk ports as access ports, or forgetting to allow the needed VLANs on the 802.1Q trunk between switches.
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An interface is configured with 10.24.7.158/27. What is the broadcast address of that subnet?
2Which two statements accurately compare TCP and UDP? (Choose two.)
3Which medium is the most common choice for a 10G uplink between wiring closets on different floors of the same building?
4At which OSI layer do routers make forwarding decisions based on logical addressing?
5Which command enables IPv6 routing on a Cisco router?
6A host sends traffic to a web server on another subnet. Which address is used as the destination MAC address in the first Ethernet frame sent by the host?
7A branch office needs four subnets from the 192.168.50.0/24 network, with each subnet supporting up to 50 hosts. Which prefix length should be used for each subnet?
8A host sends an IPv4 packet larger than the outgoing interface MTU, and the DF bit is not set. What will a router normally do?
9Which IPv6 address type is automatically created on an interface and used for communication on the local link only?
10A switch port and a host NIC have a duplex mismatch. Which symptom is most likely?
11Which rule does a router apply first when selecting a route for a destination packet?
12Why does traceroute reveal each router hop along a path?
13Which IPv6 protocol function replaces ARP?
14A branch LAN requires 50 usable IPv4 host addresses. What is the most efficient subnet mask that provides at least 50 usable hosts?
15Which cable type is commonly used to connect a switch to a router when using standard Ethernet interfaces on modern devices with auto-MDIX support?
16A host address is 2001:db8:100:20::25/64. Which portion identifies the network prefix?
17Which IPv6 prefix is used for link-local addresses?
18Which IPv6 address type is automatically created on an interface and used for link-local communication?
19Which two statements about ARP on an IPv4 Ethernet network are correct? (Choose two.)
20A switch displays the following output: Interface Status VLAN Gi1/0/5 connected 20 Gi1/0/6 notconnect 1 Gi1/0/24 trunk trunk Which interface is operating as an access port in VLAN 20?
21Which OSI layer is responsible for end-to-end segmentation, port numbers, and reliability functions such as acknowledgments?
22A router interface is configured with 192.0.2.97/28. What is the network address of the subnet?
23A host with IP address 172.16.50.130 and mask 255.255.255.192 needs to reach 172.16.50.190. Which statement is correct?
24A company wants private IPv4 addressing that can be routed internally but not on the public Internet. Which range meets that requirement?
25A network engineer must summarize the following routes before advertising them upstream: 172.16.32.0/24 172.16.33.0/24 172.16.34.0/24 172.16.35.0/24 Which summary route should be used?
26A switch port was configured for sticky MAC learning. Which two statements accurately describe how the feature behaves?
27A switch unexpectedly blocks a link toward the distribution layer. Gi1/0/24 shows a path cost of 4 while Gi1/0/23 shows a path cost of 19. Why did interface Gi1/0/24 become the root port instead of Gi1/0/23?
28Match the data format to its most accurate characteristic.
29Match the security feature to its main purpose.
30Which two statements accurately describe UDP compared with TCP?
31Which two statements accurately compare IPv4 private addresses and public addresses?
32Which two statements accurately describe ARP in an IPv4 Ethernet network?
33A host with address 192.168.1.130/26 needs to identify its local subnet. Which subnet does it belong to?
34A subnet uses the mask 255.255.255.224. How many usable host addresses does it provide?
35A host has the address 10.10.10.94/27. Which subnet contains that host?
36A subnet must support 14 usable hosts. Which prefix is the smallest that meets the requirement?
37A subnet must support at least 62 usable hosts. Which prefix will create the smallest subnet that meets the requirement?
38Which two statements accurately describe IPv6 link-local addresses?
39A subnet uses the prefix /29. How many usable host addresses are available in each subnet?
40A host with address 172.16.5.10/23 wants to determine whether 172.16.6.20 is on the same local network. What is the correct conclusion?
41Match each address-related concept to its most accurate meaning.
42A host is configured as 192.168.100.65/26. What is the valid host range for its subnet?
43A subnet requires 200 usable host addresses. Which prefix is the smallest that meets the requirement?
44Which two statements accurately describe the role of a switch MAC address table?
45A host with address 10.0.0.130/25 needs to identify its subnet. Which subnet is correct?
46A host is assigned 192.168.10.33/28. Which subnet contains that host?
47Match each common network device or concept to its primary role.
48A host address is 172.16.8.70/26. What is the network address of its subnet?
49A network requires at least 500 usable host addresses in one IPv4 subnet. Which prefix is the smallest that meets the requirement?
50A subnet has the network address 192.168.20.128/26. What is the broadcast address?
51A subnet uses the prefix /22. How many usable host addresses are available?
52A host is configured as 192.168.50.130/25. Which address is the broadcast address for its subnet?
53A host uses the subnet mask 255.255.254.0. Which prefix length does this represent?
54Which two statements accurately describe a default gateway from a host perspective?
55A host is configured with 10.10.10.130/25. What is the network address of its subnet?
56Which two statements accurately describe subnet masks in IPv4?
57A host address is 192.168.1.14/29. Which address is the broadcast address for that host’s subnet?
58A host is configured with 172.16.10.62/27. Which address is the broadcast address for that subnet?
59A subnet must support 30 usable IPv4 host addresses. Which prefix is the smallest that meets the requirement?
60Match each basic networking service to its most accurate role.
61A host is configured as 10.10.20.190/26. Which range contains usable host addresses for that subnet?
62What prefix length corresponds to the subnet mask 255.255.255.224?
63Match each basic IPv4 concept to its most accurate role.
64A host is configured as 10.20.30.95/27. Which address is the network address of its subnet?
65A host uses address 192.168.5.126/25. Which address is the broadcast address for its subnet?
66A host uses the subnet mask 255.255.255.192. How many usable host addresses exist in each subnet?
67A host is configured with IP address 192.168.50.94/27. Which subnet contains that host?
68A subnet has the network address 192.168.30.0/26. What is the broadcast address?
69What prefix length corresponds to the subnet mask 255.255.255.248?
70A host is configured with IP address 10.10.40.78/28. Which subnet contains that host?
71A host is configured as 172.16.20.190/26. Which range contains the usable host addresses for that subnet?
72Match each networking concept to its most accurate role.
73A host address is 192.168.22.145/28. Which subnet contains that host?
74A host is configured with 10.10.10.33/27. What is the broadcast address of its subnet?
75A subnet must support at least 62 usable IPv4 host addresses. Which prefix is the most restrictive that meets the requirement?
76Which prefix length corresponds to the subnet mask 255.255.255.192?
77A host is configured with 192.168.60.33/26. Which address is the network address of its subnet?
78A host is configured with 192.168.10.129/25. Which subnet contains that host?
79A subnet uses network address 192.168.200.96/28. Which range contains the usable host addresses?
80A host is configured with IP address 172.16.100.222/27. Which address is the broadcast address for its subnet?
81Which two statements accurately compare SLAAC and DHCPv6?
82Match each IPv6 address type or concept to its most accurate description.
83A router interface is configured with the prefix 2001:db8:acad:12::/64 and uses EUI-64 to build the interface ID. What is the main purpose of EUI-64 in this context?
84A host uses the subnet mask 255.255.255.240. How many usable host addresses exist in each subnet?
85A host address is 10.10.10.14/29. Which address is the broadcast address for its subnet?
86Match each IPv6 concept to its most accurate description.
87A host is configured with IP address 192.168.70.18/30. Which addresses belong to the same subnet block?
88A host uses subnet mask 255.255.255.224. How many total addresses exist in each subnet block?
89An IPv6 host has a global unicast address and a correct default route learned from a router advertisement, but the next-hop entry shown on the host uses a link-local address rather than a global unicast address. What is the best explanation?
90A subnet uses the mask 255.255.255.252. How many usable host addresses are available in each subnet?
91An IPv6 host successfully reaches neighbors on its local segment, but it cannot reach remote IPv6 destinations. The host has a global unicast address and a correct prefix length. Which missing item is the strongest suspect?
92A host is configured with 10.1.1.34/30. Which address is the broadcast address for its subnet?
93A host address is 192.168.88.66/27. Which address is the network address of the subnet?
94Which two statements accurately describe the relationship between a network address and a broadcast address in IPv4 subnetting?
95A host address is 192.168.14.222/28. Which address is the broadcast address of its subnet?
96In a network running STP, SW2 became the root bridge for VLAN 10. Both SW1 and SW2 have the same bridge priority. Why did SW2 become the root?
97A host address is 192.168.50.158/27. Which address is the network address of its subnet?
98A host address is 172.31.9.200/27. Which address is the first usable host in that subnet?
99A host address is 10.100.12.94/26. Which address is the broadcast address for that subnet?
100A host address is 192.168.90.33/28. Which address is the last usable host in the subnet?
101A host address is 10.77.4.141/28. Which address is the network address of the subnet?
102A host address is 10.55.8.117/29. Which address is the network address of the subnet?
103A host address is 172.22.14.99/27. Which address is the broadcast address of the subnet?
104Which field in an IPv4 packet is primarily used to prevent packets from looping forever in the network?
105Exhibit: A host has address 192.168.14.77/27. Which address is its valid default gateway if the first usable address in the subnet is chosen for the router interface?
106Exhibit: A laptop has IP address 10.20.30.44/27. Which address is its directed broadcast for that subnet?
107Exhibit: A host on VLAN 10 can ping the local SVI but not a server in VLAN 20. The Layer 3 switch has both VLAN interfaces up. What is the next item to verify first?
108A support engineer is explaining why a host uses ARP before sending a frame on an Ethernet LAN. Which two statements are correct?
109An engineer is reviewing transport protocols for a new application. Which two characteristics are associated with TCP rather than UDP?
110A network technician is troubleshooting a link between two Cisco switches, SW1 and SW2, connected via a single-mode fiber optic cable. The interface on SW1 is up/up, but the interface on SW2 remains down/down. The technician has verified that the fiber cable is not damaged and that the SFP modules are correctly seated. Which configuration change should the technician make to resolve the issue?
111An engineer is deploying a new Cisco Catalyst 9300 switch in a campus wiring closet. The uplink to the distribution switch uses a 1000BASE-LX SFP module. After connecting the fiber, the interface shows 'up/up' but the engineer notices that the 'input errors' counter is incrementing rapidly, with many CRC errors, runts, and giants being reported. What is the most likely cause of these input errors?
112A network technician connects a new Cisco switch to an existing access switch using a Category 5e copper patch cable. The link fails to come up, and the interface status shows 'err-disabled'. The technician checks the interface diagnostics and the running configuration. What action should the technician take to resolve the problem?
113Which TWO statements about SFP transceivers and fiber optic cabling are correct?
114Which TWO statements accurately describe characteristics of copper and fiber optic cabling used in modern Ethernet networks?
115A network technician is troubleshooting a connectivity issue between two hosts on different subnets. During the analysis, the technician captures packets and observes that the data link layer frames are being stripped and rebuilt at each router hop. Which layer of the OSI model is responsible for encapsulating the original data into segments before transmission from the source host?
116A network technician is troubleshooting a connectivity issue between two hosts. Host A sends a web request to Host B. The technician captures packets on the link between the two hosts and sees the data as '01010101...'. At which layer of the OSI model is this data being transmitted, and what is the correct PDU name for this layer?
117Which TWO statements correctly describe the encapsulation and de-encapsulation process at the transport layer of the OSI model?
118Which TWO statements accurately describe the encapsulation process in the TCP/IP model as data moves from the application layer to the network access layer?
119Drag and drop the PDU names on the left to the correct OSI model layers on the right.
120A network administrator notices that a workstation connected to a Cisco switch port cannot communicate with other devices on the same VLAN. The switch port is up/up, but the workstation reports slow performance and intermittent connectivity. What is the most likely cause of this issue?
121A network technician is troubleshooting connectivity between two directly connected Cisco switches. Hosts on VLAN 10 connected to SwitchA cannot ping the default gateway on SwitchB. The interface on SwitchB shows up/up, but the interface on SwitchA shows up/down. The technician examines the interface configuration and status on SwitchA. What is the most likely cause of this issue?
122A network administrator is troubleshooting connectivity issues between two switches. Hosts connected to Switch A cannot ping hosts on Switch B. The link between the switches shows as up/up on both ends, but interface error counters (CRC, runts) are increasing rapidly. What should the administrator do to resolve the issue?
123A network administrator is troubleshooting connectivity between two directly connected Cisco switches. Hosts on VLAN 10 connected to Switch A cannot ping the default gateway on Switch B. The interface on Switch A shows 'up/up' but there are excessive CRC errors and runts. The administrator checks the interface configuration on both switches. What is the most likely cause of the issue?
124A network technician is troubleshooting a connectivity issue between two directly connected switches, SW1 and SW2. Hosts on VLAN 10 connected to SW1 can ping each other but cannot ping the default gateway or any host on VLAN 10 connected to SW2. The interface on SW1 is up/up, but the interface on SW2 is up/down. What is the most likely cause of the problem?
125Which TWO interface issues can be identified by analyzing the output of the 'show interfaces' command?
126Which TWO symptoms are most likely to appear in the output of 'show interfaces' when a duplex mismatch exists between a switch port and a connected host?
127A user on VLAN 10 reports that they cannot ping the default gateway at 192.168.10.1 from their PC with IP 192.168.10.50/24. The switch interface connecting to the PC is up/up, and the PC shows a valid IP configuration. What is the most likely cause of this connectivity failure?
128A network engineer is troubleshooting connectivity issues for hosts in VLAN 10. Hosts in VLAN 10 are unable to ping the default gateway at 192.168.10.1. The engineer checks the switch configuration and notices that the SVI for VLAN 10 is configured with an IP address, but the interface is in a down/down state. What is the most likely cause of this issue?
129Which TWO statements correctly describe the configuration and verification of IPv4 and IPv6 parameters for host connectivity, including default gateway, DNS, and subnet masks?
130Which TWO statements correctly describe the configuration and verification of IPv4 and IPv6 parameters for host connectivity?
131A network administrator is configuring a new Windows workstation on a small office network that uses IPv4 addressing. The workstation must be able to communicate with devices on other subnets and resolve hostnames via a company DNS server at 10.10.10.5. The administrator has already set the IP address to 10.10.10.10 and the subnet mask to 255.255.255.0. Which additional parameter must be configured to meet both requirements?
132A junior network engineer is configuring a new Windows 10 workstation to connect to the corporate network. The network uses a /24 subnet mask and has a default gateway of 192.168.1.1. The workstation obtains its IP address automatically from a DHCP server, but the engineer needs to manually set a static IPv4 address of 192.168.1.50 and ensure the workstation can reach the internet. Which configuration step must the engineer take to satisfy these requirements?
133A network administrator is troubleshooting a wireless connectivity issue in a large office. Users on the 5 GHz band report intermittent disconnections and slow performance, while 2.4 GHz clients are unaffected. The office uses a Cisco 9800 WLC with APs that support 802.11ac Wave 2. The administrator checks the WLC's RF profile and notices a high number of channel utilization reports on channel 36. What is the most likely cause of the problem?
134Which statement correctly describes a feature of WPA3 security in wireless LANs?
135Which TWO statements accurately describe wireless LAN fundamentals for CCNA 200-301 v2.0? (Choose two.)
136A network administrator is troubleshooting a Windows 10 client that cannot reach the internet. The client is connected to a Cisco switch port configured as an access port in VLAN 100. The administrator runs ipconfig on the client and sees an IP address of 169.254.10.15 with a subnet mask of 255.255.0.0. The switch port shows status up/up. What is the most likely cause of the issue?
137Which TWO commands can a network technician use on a modern Linux host to verify the IP address configuration and test reachability to a remote server?
138A network administrator is troubleshooting a Windows 10 client that cannot access a web server at 192.168.1.100. The client has an IP address of 192.168.1.50/24 and can ping its default gateway (192.168.1.1) successfully, but ping to 192.168.1.100 fails. Which command should the administrator run next to verify the client's current network connections and identify potential issues with active sessions?
139A network administrator receives a report that a user on a Windows laptop cannot connect to the internet, although other devices on the same subnet are working. The administrator runs `ipconfig` on the laptop and sees an IP address of 169.254.15.22 with a subnet mask of 255.255.0.0 and no default gateway. Based on this output, what is the most likely cause of the connectivity issue?
140A network engineer is troubleshooting a link between two Cisco Catalyst 9300 switches that are connected via a 10GBASE-SR SFP+ module on each end over OM3 multimode fiber. The link is up, but the interface counters show a high number of CRC errors and runts. The engineer runs 'show interfaces Gi1/0/1' and 'show interfaces Gi1/0/1 transceiver details'. What is the most likely cause of the errors?
141A network technician is troubleshooting a newly installed fiber link between two Cisco Catalyst 9300 switches. The link is up, but the interface shows excessive CRC errors and input errors. The technician runs 'show interfaces' and 'show interfaces transceiver details' on the suspect interface. Based on the output, what is the most likely cause of the errors?
142A network engineer is troubleshooting a link between two Cisco Catalyst 9300 switches that are connected via a single-mode fiber optic cable. The link is up, but the interface counters show a high number of CRC errors and frame check sequence (FCS) errors. The interface is configured for 1000 Mbps and full duplex on both ends. What is the most likely cause of these errors?
143Which TWO statements about fiber optic cables and SFP/SFP+ transceivers are correct?
144Which TWO statements about fiber optic cable types and SFP transceivers are correct?
145Drag and drop the cable/transceiver types on the left to the correct descriptions on the right.
146A network technician is troubleshooting a connectivity issue where a host cannot communicate with a remote server. The technician notices that frames are being dropped at an intermediate switch. At which OSI model layer does the switch primarily operate, and what is the Protocol Data Unit (PDU) used at that layer?
147A network engineer is troubleshooting a connectivity issue between two hosts on different subnets. The sending host has constructed a packet with a destination IP address of 192.168.2.10. As the packet travels down the OSI model layers on the sending host, which Protocol Data Unit (PDU) name is assigned to the data at the Transport layer after TCP segments are created, and at which layer does the IP address get encapsulated?
148A network technician is troubleshooting a connectivity issue where a user's email client cannot send messages, but the client can receive emails. The technician uses a protocol analyzer and sees that the client is successfully resolving the mail server's domain name to an IP address and establishing a TCP connection, but the server responds with an application-layer error. At which layers of the OSI model are the problem and the successful operations occurring, respectively?
149A network administrator is troubleshooting a connectivity issue between two hosts on different subnets. The administrator captures packets on the source host and notices that the frames contain the correct source and destination MAC addresses but the encapsulated packets have incorrect source and destination IP addresses. According to the OSI model, which layer is most likely responsible for this issue?
150Which TWO statements correctly describe the OSI model layers and their corresponding PDU names during encapsulation?
151Which TWO statements correctly describe the encapsulation process at the OSI model Transport layer?
152Which TWO statements accurately describe the responsibilities of the OSI model's Transport layer?
153A network engineer is troubleshooting intermittent connectivity on an access switch port connected to a server. The output of 'show interfaces gigabitEthernet 1/0/24' shows an increasing number of runts and giants, but no CRC errors. The 'show interfaces status' command indicates the port is in 'err-disabled' state every few hours and must be manually re-enabled. What is the most likely cause of this issue?
154A network engineer notices that users on VLAN 100 are experiencing intermittent connectivity to the server farm. The switch connecting these users shows no errors on the uplink interface, but the server farm switch reports a high number of input errors on its connected interface. The engineer runs 'show controllers' on the server farm switch. What is the most likely cause of the issue?
155Which TWO of the following are valid interpretations of errors seen in the output of the 'show interface' command?
156Which TWO interface errors are most likely caused by a mismatch in duplex settings between two connected switches?
157Which TWO statements correctly describe the causes or implications of CRC errors, runts, giants, or output errors as seen in the output of 'show interface' or 'show interface status'?
158A network engineer is troubleshooting an issue where a Windows 10 workstation (Host-A) cannot reach the internet, but can ping the local default gateway. The engineer runs 'ipconfig /all' on Host-A and reviews the output. What is the most likely cause of the problem?
159A network administrator is troubleshooting an IPv6 connectivity issue on a newly deployed router. The router's G0/0/0 interface is configured with an IPv6 address using EUI-64, but hosts on that subnet cannot reach the router's link-local address. The administrator runs 'show ipv6 interface g0/0/0' and sees that the interface is up/up but the IPv6 address is not in the expected format. What is the most likely cause of the problem?
160Which TWO statements correctly describe IPv4 and IPv6 host configuration?
161A network administrator is troubleshooting a Windows 10 workstation that cannot access the internet. The workstation receives an IPv4 address starting with 169.254.x.x. The network uses DHCP, and other workstations on the same subnet are working correctly. What is the most likely cause of this issue?
162A network administrator is configuring a new Windows 10 workstation on a network that uses DHCP. The workstation receives an IPv4 address of 169.254.10.20 with a subnet mask of 255.255.0.0 and no default gateway. The user cannot access the internet or other subnets. What is the most likely cause of this issue?
163A network engineer is troubleshooting a wireless performance issue in a dense office environment. Clients on the 5 GHz band are experiencing low throughput even though they are close to the AP. The AP is a Cisco 9130AXI running IOS-XE 17.9. What is the most likely cause of the poor performance?
164Which TWO statements correctly describe differences between 802.11ac (Wi-Fi 5) and 802.11ax (Wi-Fi 6)?
165Drag and drop the wireless terms on the left to the correct descriptions on the right. Options: A: SSID: The network name broadcast by an access point to identify the wireless network. B: BSSID: The MAC address of the access point's radio interface, used to uniquely identify a BSS. C: RSSI: A measurement of the power level of the received radio signal, indicating signal strength. D: DFS: A mechanism that allows wireless devices to avoid interference with radar systems by dynamically selecting channels.
166A network technician is troubleshooting a connectivity issue for a PC connected to switch port Gi1/0/12. The PC can ping its default gateway (192.168.10.1) but cannot ping a server at 192.168.20.10. The switch is configured with VLAN 10 for the access port and is connected to a router-on-a-stick. The technician runs 'show vlan brief' and 'show interfaces trunk' on the switch. What is the most likely cause of the problem?
167Which TWO commands would a network administrator use to verify that a client has received a valid IP address from a DHCP server and can resolve domain names to IP addresses?
168Which TWO commands would a network engineer use to verify that a Windows client has received an IP address from a DHCP server and can resolve a domain name to an IP address?
169Which command or tool would a network engineer use to verify if a client has a duplicate IP address conflict on the local subnet?
170A network administrator is troubleshooting a user's wired workstation that cannot access the internet. The user reports that the workstation was working earlier today. The administrator runs 'ipconfig /all' on the workstation and sees an IP address of 169.254.10.55. What is the most likely cause of this issue?
171A network administrator receives a call from a user who cannot access any external websites from their wired workstation. The user can ping the default gateway successfully, but fails to ping 8.8.8.8. The administrator runs ipconfig /all on the workstation and sees an IP address of 192.168.1.50, subnet mask 255.255.255.0, and default gateway 192.168.1.1. What is the most likely cause of this issue?
172Drag and drop the following steps into the correct order to install a new fiber optic cable and SFP module on a Cisco switch, then verify the interface status.
173Which TWO statements accurately describe the characteristics and deployment considerations for fiber optic cabling in a modern enterprise network?
174Drag and drop the following steps into the correct order to sequence the TCP three-way handshake between a client and a server.
175Which of the following correctly describes the sequence of the TCP three-way handshake between a client and a server?
176Drag and drop the following steps into the correct order to describe the TCP three-way handshake process between a client and a server.
177Which single OSI model layer is responsible for both end‑to‑end reliable data delivery and segmenting data into smaller units?
178Drag and drop the following steps into the correct order to isolate CRC errors, duplex mismatches, and flapping on a Cisco IOS-XE interface.
179Which of the following shows the correct order of steps to troubleshoot a suspected duplex mismatch and CRC errors on a Cisco IOS-XE interface?
180Drag and drop the following steps into the correct order to isolate and resolve interface CRC errors, duplex mismatches, and flapping on a Cisco IOS-XE switch.
181Drag and drop the following troubleshooting steps into the correct order to isolate CRC errors, duplex mismatches, and flapping on a Cisco IOS-XE interface.
182Drag and drop the following steps into the correct order to troubleshoot a suspected duplex mismatch and CRC errors on a Cisco switch interface using CLI commands.
183Which TWO interface error counters indicate a Layer 1 issue?
184Which TWO of the following are essential IPv4 host parameters that must be correctly configured for a host to communicate with devices on remote networks?
185Drag and drop the following steps into the correct order to configure a WLAN for WPA3-Enterprise on a Cisco WLC and sequence a wireless client association process.
186Drag and drop the following steps into the correct order to configure a WPA3 SSID on a Cisco WLC and complete a wireless client association.
187Drag and drop the following steps into the correct order to configure a new WLAN on a Cisco WLC using IOS-XE CLI, including WPA3-Personal security, and to complete a wireless client association with DHCP.
188Which TWO statements correctly compare 802.11ac and 802.11ax features?
189Drag and drop the 802.11 standards on the left to their correct frequency band and maximum throughput on the right.
190Drag and drop the following troubleshooting steps into the correct order to diagnose a client connectivity issue using the OSI bottom-up method.
191Drag and drop the following troubleshooting steps into the correct order to diagnose a client connectivity issue using the OSI bottom-up method. The client cannot access a web server by its FQDN.
192You are connected to R1. The link between R1 and R2 is experiencing intermittent connectivity and poor performance. Review the provided show interface output to identify the root cause(s) of the issue, then apply the necessary configuration changes to resolve the problem and restore full connectivity. Output from R1: ``` GigabitEthernet0/0 is up, line protocol is up (connected) Hardware is Gigabit Ethernet, address is aaaa.bbbb.cccc (bia aaaa.bbbb.cccc) Internet address is 192.168.1.1/30 MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec) Half-duplex, 100Mb/s, link type is auto, media type is RJ45 output flow-control is unsupported, input flow-control is unsupported ARP type: ARPA, ARP Timeout 04:00:00 Last input 00:00:01, output 00:00:01, output hang never Last clearing of "show interface" counters 00:01:23 Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: fifo Output queue: 0/40 (size/max) 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 150 packets input, 1500 bytes, 0 no buffer Received 0 broadcasts (0 multicasts) 0 runts, 0 giants, 0 throttles 150 input errors, 150 CRC, 0 frame, 0 overrun, 0 ignored 0 watchdog, 0 multicast, 0 pause input 0 input packets with dribble condition detected 200 packets output, 2000 bytes, 0 underruns 0 output errors, 0 collisions, 0 interface resets 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier 0 output buffer failures, 0 output buffers swapped out ```
193You are connected to R1. The link between R1 and R2 is experiencing packet loss and slow performance. Examine the following partial show interface output: R1# show interfaces gigabitEthernet 0/0 GigabitEthernet0/0 is up, line protocol is up Duplex: Full, Speed: Auto, 100Mb/s Input errors: 12345, CRC: 5000, frame: 0, overrun: 0, ignored: 0 R2# show interfaces gigabitEthernet 0/0 GigabitEthernet0/0 is up, line protocol is up Duplex: Half, Speed: Auto, 100Mb/s Input errors: 0, CRC: 0, collisions: 5000, late collisions: 0 Identify the root cause of the issue, and apply the necessary fix on R1 to resolve the problem.
194You are troubleshooting connectivity between R1 and R2. The link is down, and you need to identify and fix the issue. Examine the provided 'show interfaces' output and running configuration, then apply the necessary commands to restore connectivity.
195You are connected to R1. The link between R1 and R2 is down. The output of 'show interfaces gigabitEthernet0/0' on R1 shows: 'GigabitEthernet0/0 is administratively down, line protocol is down (disabled)', with IP address 203.0.113.1/30, MTU 1500, and no input/output errors. Determine the root cause and configure the necessary fix to bring the interface up and restore connectivity.
196You are connected to R1. The network administrator reports that hosts on VLAN 10 cannot communicate with the server attached to R2's GigabitEthernet0/1 interface. Troubleshoot and resolve the issue. Identify the root cause and apply the necessary fix on R1.
197You are connected to R1. The network team reports intermittent connectivity between R1 and R2. Examine the following `show interface` output from R1 to identify the root cause of the issue. Then apply the necessary configuration commands on R1 to resolve the problem. GigabitEthernet0/0 is up, line protocol is up Internet address is 10.0.0.1/30 MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec) Full-duplex, 100Mb/s, media type is RJ45 output flow-control is unsupported, input flow-control is unsupported Last input 00:00:01, output 00:00:01, output hang never Last clearing of "show interface" counters never Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: fifo Output queue: 0/40 (size/max) 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 100 packets input, 8000 bytes, 0 no buffer Received 0 broadcasts, 0 runts, 0 giants, 0 throttles 100 input errors, 100 CRC, 0 frame, 0 overrun, 0 ignored 0 output errors, 0 collisions, 0 interface resets 0 output buffer failures, 0 output buffers swapped out
198You are connected to R1 via the console. R1 has two directly connected routers: R2 and R3. Currently, R1 cannot reach R2's loopback interface (203.0.113.1/32). Additionally, R3 is IPv6-only and must be reachable from R1 using a statically assigned global unicast address. Configure R1's interfaces and static routes so that: (1) R1 can ping R2's loopback, (2) R1 can ping R3's IPv6 address 2001:db8:acad:2::1/64, and (3) R1's IPv6 address on the link to R3 is derived using EUI-64.
199You are connected to R1. Configure IPv4 and IPv6 addressing on R1's interfaces so that R1 can reach R2's loopback0 (192.0.2.1/32) and R2's IPv6 loopback0 (2001:db8:1::1/64). R1 has a misconfigured subnet mask on G0/0 and is missing its default gateway. Additionally, R1 has a duplicate IPv4 address on G0/1 that must be corrected. Use EUI-64 for R1's IPv6 link-local address on G0/0 and static IPv6 for the global unicast address on G0/1.
200You are connected to R1. Configure IPv4 and IPv6 addressing on R1's interfaces and verify reachability to R2. The current configuration has a wrong subnet mask on G0/0, missing default gateway for IPv4, and R1's IPv6 address is configured using EUI-64 while R2 uses a static IPv6 address. Fix these issues so that R1 can ping both R2's IPv4 and IPv6 addresses.
201You are connected to R1 via console. The network consists of R1, R2, and a multilayer switch MLS1. R1's GigabitEthernet0/0 connects to MLS1's GigabitEthernet1/0/1 (VLAN 10), and MLS1's GigabitEthernet1/0/2 connects to R2's GigabitEthernet0/0. The goal is to enable IPv6 communication between R1 and R2 across the layer-3 switch. Currently, R1 and R2 cannot ping each other's IPv6 addresses. Configure R1's G0/0 with the IPv6 prefix 2001:db8:1:10::/64 using EUI-64, and R2's G0/0 with static IPv6 address 2001:db8:1:10::2/64. Also ensure MLS1 has IPv6 routing enabled and an IPv6 address on VLAN 10 (2001:db8:1:10::3/64). Troubleshoot and fix any layer-2 or layer-3 issues preventing connectivity.
202You are connected to R1 via console. R1 and R2 are directly connected via GigabitEthernet0/0. Your task is to configure IPv4 and IPv6 addressing on both routers so that they can ping each other's IPv4 and IPv6 addresses. The current configuration has intentional faults: R1's IPv4 subnet mask is incorrect, R2 is missing its default gateway, and R1's IPv6 address uses EUI-64 but is not working due to a duplicate IP. Correct the IPv4 mask on R1, assign a static IPv6 address on R2, and ensure both routers can reach each other.
203You are connected to R1. The network administrator has partially configured IPv4 and IPv6 on the interfaces. However, PC1 (connected to R1's G0/1) cannot reach PC2 (connected to R2's G0/1). Configure R1 and R2 so that PC1 can ping PC2. Fix any addressing errors. Use IPv4 subnet 192.0.2.0/30 for the link between R1 and R2, and 198.51.100.0/24 for the PC LANs. For IPv6, use 2001:db8:1::/64 on R1's G0/1 and 2001:db8:2::/64 on R2's G0/1, with R1's G0/1 using EUI-64 and R2's G0/1 using a static address 2001:db8:2::1/64.
204You are connected to R1. Configure IPv4 and IPv6 addressing on R1's GigabitEthernet0/0 and GigabitEthernet0/1 interfaces so that R1 can ping both R2's IPv4 address (203.0.113.2) and R2's IPv6 address (2001:db8:1::2). The current configuration has an incorrect subnet mask on G0/0, missing default gateway, and R1's G0/1 has a duplicate IPv4 address with R3. Also, use EUI-64 for IPv6 on G0/0 and static IPv6 assignment on G0/1. Ensure all issues are resolved and connectivity verified.
205You are connected to R1. The network has R1, R2, and a multilayer switch MLS1. Configure IPv4 and IPv6 addressing on R1's interfaces so that R1 can ping both R2 (198.51.100.2) and MLS1 (203.0.113.2) via IPv4. Additionally, configure IPv6 on G0/1 using EUI-64 with prefix 2001:db8:1::/64 and verify that R1 can ping the IPv6 address of MLS1 (2001:db8:1::2). The current configuration has incorrect subnet masks and missing IPv6 settings, causing reachability failures.
206You are managing a Cisco WLC (192.168.1.10) via its web UI. The wireless network 'CorpSecure' has been configured but clients cannot associate. Some report 'wrong password' errors; others see the SSID but fail to connect. Additionally, management access to the WLC web UI is intermittent. Identify and resolve the issues so that wireless clients can successfully associate with 'CorpSecure' using WPA3-Personal and the WLC web UI is reliably accessible from the management VLAN (VLAN 10).
207You are troubleshooting a wireless client association failure on a Cisco WLC. The client is unable to connect to the corporate SSID 'CorpNet' and reports an authentication error. Review the WLC configuration and fix the issue so that the client can associate and obtain an IP address from VLAN 100. The WLC management IP is 192.168.1.10/24.
208You are troubleshooting a wireless client connectivity issue on the Cisco WLC at 192.168.1.100. The client reports it can see the SSID 'CorpNet' and successfully associates, but cannot obtain an IP address or reach network resources. The WLAN is already configured with WPA3 security, and the SSID should remain hidden. Identify and correct the configuration issue.
209You are connected to WLC-1 via the management interface (192.168.1.100/24). The wireless network 'CustomerNet' uses WPA3-Personal, but clients are failing to associate. The SSID is hidden and the correct VLAN is 30. Configure the WLAN and SSID parameters to allow successful client associations and verify the configuration.
210You are managing a Cisco WLC (WLC-1) with IP 10.10.10.10. A wireless client reports it can see the SSID 'CorpNet' but fails to associate. The SSID is configured for WPA3, but the client only supports WPA2. Additionally, the WLAN is mapped to VLAN 100, but the AP is on VLAN 10, causing a mismatch. Your task: reconfigure the WLAN to use WPA2-PSK with AES encryption, correct the VLAN assignment to 10, and ensure the SSID is hidden. Also, verify that management access via the WLC web UI is restricted to the 192.168.1.0/24 subnet.
211You are connected to WLC-1 via SSH. A new SSID 'CorpSecure' must be configured for 5 GHz clients using WPA3-Personal. However, after creation, clients can see the SSID but fail to associate. Review the WLC configuration and fix the issue so that clients can successfully associate and obtain an IP address from VLAN 100 (subnet 10.0.100.0/24).
212You are connected to the Cisco WLC (WLC-1) via its management IP 192.168.1.10. The wireless network 'CorpNet' is configured but clients cannot associate. Troubleshoot and resolve the issue: clients report 'Association failed' and the SSID is not visible in site surveys. Ensure that after your fix, the SSID is broadcast, WPA3 is used, and the WLAN is mapped to VLAN 20. Also, verify the WLC management interface is accessible over HTTPS.
213You are connected to a Cisco 9800 WLC (WLC1) via its management interface. A wireless client reports association failures with SSID 'CorpNet'. The client uses WPA3-Personal, but the WLAN is configured for WPA2. Additionally, the SSID is hidden and the client is on the wrong VLAN (VLAN 20 instead of VLAN 100). Fix these issues so the client can associate successfully with WPA3, on VLAN 100, and with the SSID broadcast enabled.
214You are troubleshooting a connectivity issue for a remote worker who reports being unable to access the internet. The worker's PC is connected to switch S1, which is connected to router R1. You have console access to R1. The router's interface G0/0 is configured with IP 192.168.1.1/24, and the DHCP pool 'LAN' currently has network 192.168.1.0 255.255.255.0 and default-router 192.168.1.254. The PC has obtained an IP address of 192.168.1.100 from DHCP and a subnet mask of 255.255.255.0, but cannot ping 8.8.8.8. Identify the fault and configure R1 to restore internet access for the PC.
215You are troubleshooting a client connectivity issue on PC1, which is connected to switch SW1. PC1 reports that it cannot access the internet, but it can ping its default gateway (192.168.1.1). The network uses VLAN 10 for the client subnet. Examine the following show outputs: On PC1, ipconfig shows IP 192.168.1.10, default gateway 192.168.1.1, DNS server 192.168.1.1. On SW1, show running-config includes 'interface Vlan10' with IP 192.168.1.1 255.255.255.0, but no 'ip dns server' and no 'ip name-server' commands. SW1's show ip route displays a default route via 203.0.113.1. Identify the root cause. Configure the necessary fix on the appropriate device to restore full connectivity.
216You are troubleshooting connectivity for a wireless client connected to the home network shown below. The client has obtained an APIPA address (169.254.x.x), indicating DHCP failure. Verify the DHCP server configuration on R1 and correct the issue so that the client receives a valid IP address from the 192.168.1.0/24 subnet.
217You are troubleshooting a PC (PC-A) connected to switch SW1, which is connected to router R1. PC-A has an APIPA address (169.254.23.45) and cannot reach the internet (203.0.113.1). You confirm that R1 has a correctly configured DHCP pool for the 192.168.10.0/24 subnet, but the DHCP service is not enabled. The network uses VLAN 10 with subnet 192.168.10.0/24. Verify and correct the configuration on PC-A, SW1, and R1 to restore full connectivity.
218You are connected to R1 via the console. The network administrator reports that PC1 (connected to R1's GigabitEthernet0/1) cannot reach the internet. Troubleshoot the issue step by step. The current configuration and show outputs are provided.
219You are connected to R1 via console. PC1 is connected to R1's GigabitEthernet0/1 interface and is configured with a static IP address. PC1 cannot reach the internet (203.0.113.1). Identify and resolve the connectivity issue. Configure R1 to restore full connectivity for PC1.
220You are troubleshooting a PC connected to switch SW1. The PC cannot access the internet. SW1 is connected to router R1 via port G0/1. R1 provides default gateway and DHCP services. Analyze the provided show output and fix the connectivity issue so that the PC can ping 8.8.8.8. === Show output from R1 === <pre> R1# show ip interface brief Interface IP-Address OK? Method Status Protocol GigabitEthernet0/0 unassigned YES manual administratively down down GigabitEthernet0/1 10.0.0.1 YES NVRAM up up </pre> === Show output from PC === <pre> C:\> ipconfig Ethernet adapter Ethernet0: Connection-specific DNS Suffix . : IPv4 Address. . . . . . . . . . : 169.254.123.45 Subnet Mask . . . . . . . . . . : 255.255.0.0 Default Gateway . . . . . . . . : </pre> === Show output from SW1 === <pre> SW1# show vlan brief VLAN Name Status Ports ---- -------------------------------- --------- ------------------------------- 1 default active Gi0/1, Gi0/2, Gi0/3 </pre>
221You are connected to R1 via console. R1's GigabitEthernet0/1 interface connects to a remote site switch over a 2 km fiber link. The current configuration shows speed and duplex set to 1000 Mbps and full, but the interface is down/down due to an SFP mismatch. Review the exhibit, identify the problem, and correct it so that the interface comes up and communicates at the correct speed and duplex. Additionally, ensure the interface is configured to auto-negotiate properly for future cable replacements.
222You are connected to R1 via the console. R1 and R2 are directly connected via their GigabitEthernet0/0 interfaces. The link between them is down. Your task is to diagnose and fix the issue: R1's interface is configured for 100 Mbps full-duplex, but R2 is using auto-negotiation. Additionally, the link requires a Gigabit Ethernet connection over a distance of 5 km. Configure R1's interface to match R2's settings (auto-negotiation) and then select and install the correct SFP module to support the 5 km distance requirement.
223You are connected to R1 via the console. R1 and R2 are connected via a fiber link using SFPs. The link is not coming up. Configure the correct SFP type on R1's interface GigabitEthernet0/0 to support the required 2 km distance, and fix any auto-negotiation or speed/duplex misconfiguration so that the link becomes operational.
224You are troubleshooting a link between R1 (G0/0) and R2 (G0/0). The link is up but experiencing packet loss. You suspect an interface speed/duplex mismatch or SFP issue. Configure R1's interface to match the correct speed and duplex, and replace the SFP module if necessary to support a required distance of 40 km over single-mode fiber.
225You are connected to R1 via console. R1 is directly connected to R2 over a 1000BASE-T link that is failing to come up. Configure interface GigabitEthernet0/0 on R1 with the correct speed and duplex settings to match R2's configuration, and then verify the link is operational. Additionally, determine the appropriate SFP type for a new 40 km fiber link between R1 and R2.
226You are connected to R1. The link between R1's GigabitEthernet0/0 and R2's GigabitEthernet0/0 should operate at 1 Gbps full duplex, but the interface is showing errors and only negotiating at 100 Mbps half duplex. Diagnose and fix the fault, then verify the link is stable at the correct speed and duplex.
227You are connected to R1 via console. The link between R1 and R2 is experiencing packet loss and CRC errors. Configure interface speed and duplex on R1's GigabitEthernet0/0 to match R2's settings, then replace the SFP module with one that supports the required 2 km distance. Finally, verify the interface is operational without errors.
228Which three of the following are characteristics of Layer 2 Ethernet switches that improve network performance? (Choose three.)
229Which three statements about the Spanning Tree Protocol (STP) are true? (Choose three.)
230Which three of the following are characteristics of wireless LAN (WLAN) operation in the 2.4 GHz and 5 GHz bands? (Choose three.)
231Which three of the following are characteristics of Layer 2 Ethernet switches that support VLANs? (Choose three.)
232Which three options correctly describe how a router processes a packet destined for a remote network? (Choose three.)
233Which three statements are true about the operation of Dynamic Host Configuration Protocol (DHCP) in an enterprise network? (Choose three.)
234Which three statements about Power over Ethernet (PoE) and PoE+ standards are correct? (Choose three.)
235Which three of the following are correct steps in the process of CDP (Cisco Discovery Protocol) neighbor discovery? (Choose three.)
236Drag and drop the following steps into the correct order to describe the data encapsulation process as it flows down the OSI model from the source host.
237Drag and drop the following steps into the correct order to configure a Windows 10 host with a static IPv4 address, subnet mask, and default gateway.
238Drag and drop the following steps into the correct order to diagnose and resolve a duplex/speed mismatch causing interface errors on a Cisco switch.
239Drag and drop the following steps into the correct order to troubleshoot a Windows client that is unable to reach a remote server.
240Drag and drop the following steps into the correct order to describe how data is encapsulated as it travels down the OSI model layers.
241Drag and drop the following steps into the correct order to troubleshoot a link-down issue on a GigabitEthernet interface using an SFP transceiver.
242Drag and drop the following steps into the correct order to troubleshoot and resolve excessive interface errors caused by a duplex mismatch on a Cisco switch interface.
243Drag and drop the following steps into the correct order to configure a Cisco switch with an IPv4 management address 192.168.1.10/24, an IPv6 address 2001:db8:1::1/64, and a default gateway 192.168.1.1.
244Drag and drop the following steps into the correct order to troubleshoot a client PC that cannot connect to a remote web server.
245Drag and drop the items on the left to the correct descriptions on the right.
246Which TWO statements correctly describe interface errors and duplex mismatches on Cisco switches?
247Which TWO statements accurately describe the encapsulation process and PDU naming across the OSI and TCP/IP models?
248Which TWO statements accurately describe cabling and SFP transceiver diagnostics?
249Which TWO statements accurately describe the use of ipconfig, ping, and tracert when troubleshooting a client that cannot reach a remote server?
250Which TWO statements about SFP transceivers and interface diagnostics are true?
251Drag and drop the following steps into the correct order to enable a third-party SFP transceiver and verify its diagnostics on a Cisco switch.
252Drag and drop the following steps into the correct order to describe the encapsulation of data as it passes down the TCP/IP stack for transmission.
253A network administrator is troubleshooting slow file transfers between two servers in different access-layer switches. The administrator runs the 'show interface' command on the uplink connecting the two switches and notices a high number of CRC errors on both ends, but a high number of late collisions on only one interface; the other interface reports no late collisions.
254Two routers, R1 and R2, are connected via a serial link. The interface on R1 shows 'Serial0/0 is up, line protocol is down' and no pings succeed across the link. You check the configuration and notice R1 has 'encapsulation ppp' but R2's serial interface was mistakenly left at the default encapsulation hdlc.
255A network administrator notices that file transfers to a server are extremely slow, and on the switch interface connecting to the server, the output of 'show interfaces' indicates a high number of runts and CRC errors, but no collisions. Which of the following is the most likely cause?
256A network technician configures a Windows 10 PC with a static IPv6 address of 2001:db8:acad:1::100/64 and a default gateway of 2001:db8:acad:2::1. The PC can communicate with other hosts in the 2001:db8:acad:1::/64 subnet, but it cannot access any resources on other subnets, even though IPv4 connectivity through the same network works normally. What is the most likely reason for this issue?
257An administrator deploys a new WLAN on a Cisco 9800 WLC using WPA3-Personal (SAE) with AES encryption. A single 802.11ax laptop running Windows 10 fails to connect, displaying an authentication timeout despite entering the correct passphrase. Other clients, including legacy 802.11ac devices, connect without issue.
258A user reports they cannot access any network resources. A network administrator runs ipconfig on the user's Windows PC and sees an IPv4 address of 169.254.45.3/16. The administrator then pings the default gateway 10.0.0.1, which fails, and uses traceroute to 10.0.0.1, which shows only '1 * * * Request timed out.' What is the most likely cause of the problem?
259A network engineer replaces a failed 1000BASE-LX SFP on a core switch with a new transceiver of the same type. After connecting the single-mode fiber, the link remains down and a 'show interfaces gig1/0/49 transceiver' reveals an Rx power of –30 dBm, while the far-end SFP is transmitting at –3 dBm over a 2 km span. The fiber patch cord shows no visible damage.
260A network engineer notices that users in VLAN 10 report intermittent connectivity and slow file transfers to a server on the same switch. The engineer issues the show interfaces fa0/1 command on the switch port connected to the server and observes a high number of runts, input errors, and CRC errors, while output errors are minimal. The interface configuration shows speed 100 and duplex full.
261A network administrator has recently upgraded the corporate wireless LAN to support 802.11ax (Wi-Fi 6) and is using WPA3-Enterprise with a central WLC. Several users with new 802.11ax laptops report that they can connect to the SSID, but after a few minutes their connections drop and then re-establish, while legacy 802.11ac clients work without issues. Which action will resolve this problem?
262A user reports that they cannot access a remote server at IP address 10.10.20.50. The user's PC has IP address 192.168.1.25/24, and the default gateway is 192.168.1.1. The user can successfully ping the default gateway and other hosts on the local subnet. However, pings to 10.10.20.50 fail, and a traceroute shows only the first hop (192.168.1.1) followed by timeouts. Which of the following is the most likely cause?
263Which TWO statements about SFP transceivers and their associated cable types are correct?
264Which TWO statements are correct regarding Protocol Data Units (PDUs) and data encapsulation in the OSI model?
265A network engineer notices that the router interface GigabitEthernet0/1 is in an 'administratively down' state in the output of the show ip interface brief command, preventing connectivity to the subnet connected to that interface. What is the most likely cause?
266A host cannot communicate with its default gateway. The technician uses the show arp command on the host and sees that the ARP entry for the gateway IP is incomplete. The technician has already verified that the Ethernet cable is securely connected and the switch port is active. What should the technician do next?
267Refer to the exhibit. A network engineer is investigating intermittent connectivity complaints on a gigabit uplink between two distribution switches. The engineer runs the show interfaces GigabitEthernet0/0 command on one of the switches. Based on the output, what is the most likely cause of the errors?
268A user reports that their computer cannot access the network. The technician checks the computer's IP configuration and finds an APIPA address (169.254.x.x). The computer is connected to a switch port on VLAN 20. The DHCP server is located on VLAN 1. The technician then examines the router's interfaces using 'show ip interface brief' and sees that all interfaces shown are up/up. What should the technician do next?
269Refer to the exhibit. A network engineer is troubleshooting a connectivity issue between two routers connected via a serial link. The engineer runs the show interfaces Serial0/0/0 command on R1. Based on the output, what is the most likely cause of the problem?
270A technician is troubleshooting a connectivity issue where a workstation connected to a Cisco switch port cannot ping other hosts that are in the same VLAN 10 segment. The technician runs the show mac address-table command and notices that the workstation's MAC address is listed on VLAN 1, not VLAN 10. What is the most likely cause?
271A network engineer notices that a switch port connected to a legacy server is experiencing late collisions and the server reports excessive retransmissions. The switch port is configured for auto-negotiation and shows a negotiated speed of 100 Mbps and duplex full. The server's NIC is manually set to 100 Mbps and half-duplex. What is the most likely cause?
272A network technician replaced a faulty SFP transceiver on a switch port. After replacement, the port remains in a down/down state. The technician verifies the fiber cable is securely connected at both ends and observes that the remote switch port is also in a down/down state. What should the technician do next?
273A wireless client associates to an AP and successfully authenticates to the correct SSID, but it does not obtain an IP address. The WLC is running in local mode. What should the technician do next?
274Refer to the exhibit. A network engineer is troubleshooting a serial link between two routers that is not coming up. The engineer issues the show controllers command on one router and sees the output shown. What is the most likely cause of the issue?
275A technician is troubleshooting a dual-stack network where an IPv6-only host cannot reach an IPv4 resource. The technician issues the show ipv6 interface brief command on the local router and notices the interface facing the host has a link-local address but no global unicast address. The technician then checks the running configuration and finds that the command ipv6 unicast-routing is missing. What is the most likely cause?
276Refer to the exhibit. An administrator notices that all interfaces on R1 are in an administratively down state. The administrator issues the show version command and sees the following output. What is the most likely cause of the issue?
277A technician is troubleshooting a connection between two routers, R1 and R2, connected back-to-back using Ethernet cables. Both routers have their interfaces configured and are in an 'up/up' state. R1's interface uses 192.168.1.1/24, and R2's interface uses 192.168.2.1/24. When the technician attempts to ping R2 from R1, the ping fails. What is the most likely cause?
278A network engineer notices that after issuing the no shutdown command on interface GigabitEthernet0/0 of a router, the interface remains down. The output of show interfaces GigabitEthernet0/0 displays 'GigabitEthernet0/0 is down, line protocol is down'. The physically connected switch port is also administratively down. What is the most likely cause?
279Refer to the exhibit. A network engineer is troubleshooting a connectivity issue on R1. The serial link to R2 on interface Serial0/1 is using HDLC encapsulation, and the physical cable has been verified as good. The engineer has confirmed that the encapsulation type matches on both routers and that the clock rate is correctly configured on the DCE end. Based on the output, what is the most likely cause of the line protocol down state on Serial0/1?
280Refer to the exhibit. A network engineer is troubleshooting intermittent connectivity between a branch router and the upstream switch. The switch port is manually configured for full-duplex, and the Ethernet cable has been tested and is working properly. The engineer runs the show interfaces GigabitEthernet0/0 command on the router and receives the output shown. Based on the output, what is the most likely cause of the problem?
281A branch router has two equal-cost static routes to the same destination network. Both routes are displayed in the output of the show ip route command, and pings from the router to both next-hop IP addresses succeed. Despite this, all traffic heading toward that destination is egressing only a single interface. The technician suspects Cisco Express Forwarding (CEF) is not performing load balancing as expected. What should the technician do next?
282A network administrator is configuring VLANs on a Cisco Catalyst switch. The design requires that VLAN 10 traffic and VLAN 20 traffic share the same physical uplink to a router, but each VLAN must remain logically separate at Layer 2. The router interface is configured with 802.1Q encapsulation. Which statement correctly describes how the router will process frames arriving from both VLANs on that single physical interface?
283A network engineer is configuring a new Cisco Catalyst 9300 switch. The switch currently has all interfaces in VLAN 1, and the engineer needs to segment traffic for the Finance department. The engineer creates VLAN 20 and assigns it the name 'Finance'. Which command sequence is required to place access ports FastEthernet 1/0/1 through 1/0/10 into VLAN 20?
284A network administrator is configuring a Cisco switch. The switch has a management VLAN 99 with IP address 10.10.99.5/24 and default gateway 10.10.99.1. The administrator wants to verify that the switch can reach a server at 10.10.99.100. Which command should be used on the switch to test reachability?
285A network engineer is configuring a new Cisco switch that will carry traffic for multiple VLANs between two buildings. The link between the two switches must transport frames for VLAN 10, 20, and 30, and both switches must be able to identify which VLAN each frame belongs to. Which configuration should be applied to the inter-switch link on both switches?
286A technician is connecting a new Cisco switch to an existing switch using a copper cable. The link between the two switches must carry traffic for multiple VLANs. Which command must be configured on the interface connecting to the other switch to allow multiple VLANs to traverse the link?
287A network engineer is configuring a Cisco router interface with the IP address 192.168.10.1/24. The engineer wants to ensure that the interface can send and receive packets on the local subnet. Which command must be used to enable the interface?
288A network engineer is configuring OSPFv2 on a Cisco router. The router has two interfaces: GigabitEthernet0/0 with IP 10.1.1.1/24 and GigabitEthernet0/1 with IP 10.2.2.1/24. The engineer wants to enable OSPF on both interfaces but ensure that GigabitEthernet0/0 is elected as the Designated Router (DR) on its network segment. Which configuration achieves this?
289A junior administrator is asked to configure a Cisco router interface with the IPv4 address 10.1.1.1 and a subnet mask of 255.255.255.0 so it can route traffic for the 10.1.1.0/24 network. Which command correctly assigns this address to the interface?
290A network technician is configuring a new Cisco switch and needs to secure unused switch ports to prevent unauthorized access. The technician decides to disable the ports and place them in an unused VLAN. Which two commands are required to accomplish this on each unused interface? (Choose two.)
291A network administrator is configuring a Cisco switch port that connects to a server. The server's NIC is configured for full-duplex and 1 Gbps. The administrator wants to ensure the switch port operates at the same settings without negotiation. Which command set should be applied to the interface?
292A network technician is troubleshooting a connectivity issue between a host and a server. The host can ping the server's IP address but cannot access the server's file share using its hostname. The technician suspects a name resolution problem. Which protocol is responsible for resolving the server's hostname to its IP address in a small office network without a DNS server?
293A network administrator is deploying a new branch office that will have 500 devices in a single VLAN. The administrator wants to minimize broadcast traffic and improve performance by segmenting the network into smaller broadcast domains while keeping the design simple. Which action best accomplishes this?
294A network technician is troubleshooting a Cisco switch that is not forwarding traffic on a VLAN. The technician suspects a VLAN configuration issue. Which two commands can be used to verify VLAN configuration and port membership? (Choose two.)
295A network administrator is troubleshooting a connectivity issue between two routers, R1 and R2, connected via a serial link. R1 is configured with PPP encapsulation and CHAP authentication. R2 is configured with PPP encapsulation but no authentication. The link is down. Which statement explains the most likely cause?
296A network administrator is configuring a Cisco switch to support a new voice VLAN. The design requires that IP phones and PCs share the same switch port, with voice traffic tagged and data traffic untagged. Which two commands are required on the switch port to support this configuration? (Choose two.)
297A network administrator is configuring a Cisco router with two interfaces: GigabitEthernet0/0 and GigabitEthernet0/1. The administrator wants to configure a static route to the 10.1.1.0/24 network via the next-hop IP address 192.168.1.2. Which command correctly accomplishes this?
298A network engineer is configuring a Cisco router to provide DHCP services to a remote subnet. The router interface connected to that subnet is GigabitEthernet0/1 with IP address 192.168.20.1/24. The DHCP pool must exclude the first 10 addresses for static devices. Which configuration correctly sets up the DHCP pool?
299A network engineer is configuring OSPFv2 on a Cisco router. The router is connected to two different OSPF areas: Area 0 and Area 1. The engineer wants to summarize the routes from Area 1 into Area 0. Which router type is required to perform this summarization?
Deep-dive questions
The most-searched questions in this domain — detailed explanations, worked examples, full answer breakdowns.
You must configure and verify VLANs, trunks, IPv4/IPv6 addressing, default gateways, and static or OSPF routes, then troubleshoot with show commands. The single most important thing: confirm Layer 2 reachability and correct IP addressing before blaming routing or wireless.
The Courseiva 200-301 question bank contains 299 questions in the Network Infrastructure and Connectivity domain, covering the 20% of the exam attributed to this domain in the official Cisco blueprint. Click any question to see the full explanation and answer breakdown.
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