CCNA Practice Test 43 — 15 Questions

Question 1

Based on the exhibit, which route will be used to reach 172.20.10.33?

Accepted Answer

The static route to 172.20.10.32/27. The route used will be the one with the longest matching prefix. In practical terms, 172.20.10.33 matches both the /24 and the /27 shown, but the /27 is more specific. That means the router selects the /27 route before considering the broader /24 or any default route.

This is exactly the kind of route-table interpretation the CCNA exam likes because it rewards precise thinking about prefix boundaries.

Answer

The OSPF route to 172.20.10.0/24

Answer

The default route

Answer

No route, because the destination does not match any prefix.

Question 2

Based on the exhibit, which route will be used for destination 192.168.10.130?

Accepted Answer

The static route to 192.168.10.128/25. The route used will be the one with the longest matching prefix. In practical terms, 192.168.10.130 matches both the /24 and the /25 prefixes shown, but the /25 is more specific. Because longest-prefix match comes first, the router uses the /25 route even though other matching routes are present.

This is a clean route-table interpretation question that is very close to real exam reasoning.

Answer

The OSPF route to 192.168.10.0/24

Answer

The default route

Answer

No route at all

Question 3

Exhibit: R1 has a default route pointing to 10.1.1.2. Users lose internet access when that next hop fails, even though a floating static backup exists. Why is the backup not installed?

Accepted Answer

The primary static route remains installed because there is no tracking to remove it. A floating static route is used only when the primary route disappears from the routing table. If the primary interface stays up and the next hop becomes unreachable beyond that segment, the route can remain installed unless tracking or another detection mechanism removes it.

Answer

The backup route has a higher administrative distance and therefore is never considered

Answer

Floating statics work only with dynamic routing protocols

Answer

The backup route must use the same next hop as the primary route

Question 4

A PC connected to switch port Gi0/10 should be in VLAN 20 but receives broadcasts only from VLAN 1. Which switchport setting is most likely wrong?

Accepted Answer

switchport access vlan 20 missing or incorrect. The PC is receiving broadcasts only from VLAN 1, which indicates the switchport is not correctly assigned to VLAN 20. The most likely cause is that the 'switchport access vlan 20' command is missing or incorrect, leaving the port in its default VLAN (VLAN 1). This prevents the PC from participating in VLAN 20 and receiving its broadcasts.

Answer

switchport mode trunk

Answer

speed 1000

Answer

duplex full

Question 5

R1 is an IPv6-only branch router. The administrator wants all unknown IPv6 destinations to be sent to the upstream router at 2001:db8:ff::1. Which command best achieves that goal?

Accepted Answer

ipv6 route ::/0 2001:db8:ff::1. The correct configuration is an IPv6 default static route pointing to the upstream next hop. In practical terms, this is the IPv6 version of a route of last resort. The router does not need specific entries for every remote IPv6 network if all unknown traffic should go to the upstream device.

The key distinction is that IPv6 static routing uses IPv6 syntax and the double-colon default prefix representation. This is a foundational branch-routing concept for IPv6 deployments.

Answer

ip route 0.0.0.0 0.0.0.0 2001:db8:ff::1

Answer

ipv6 route 2001:db8:ff::/64 ::1

Answer

ipv6 default-gateway 2001:db8:ff::1

Question 6

Which two statements about OSPF neighbor requirements on a shared Ethernet segment are correct? (Choose two.)

Accepted Answer

They must be in the same OSPF area on that link.. Neighbors must agree on key parameters such as area ID and subnet, and they exchange Hello packets on the segment.

Answer

They must have identical router IDs.

Answer

They must use the same process ID number on both routers.

Question 7

Which two statements accurately describe longest-prefix match?

Accepted Answer

The most specific matching route is preferred over broader matching routes.. Longest-prefix match means the router prefers the most specific route that matches the destination. In plain language, if several routes could all work, the router chooses the one that describes the destination range most precisely. That is why a /25 wins over a /24, and a /24 wins over a /16, when all of them match the same destination.

This is a foundational routing rule. The wrong answers usually confuse route specificity with route-source trust or assume the default route is considered first. The two correct answers are the ones that keep the focus on specificity.

Answer

The default route is always preferred over a matching specific route.

Answer

Administrative distance replaces the need for longest-prefix match.

Answer

A /16 is more specific than a /24.

Question 8

Which IPv6 address type is automatically created on an interface and used for communication on the local link only?

Accepted Answer

Link-local. Every IPv6-enabled interface generates a link-local address, typically in the FE80::/10 range. It is used for neighbor discovery, local communication, and next-hop resolution on the same link.

Answer

Global unicast

Answer

Unique local

Answer

Multicast

Question 9

Which two statements accurately describe route summarization?

Accepted Answer

It can reduce the number of individual routes that must be advertised.. Route summarization combines multiple specific routes into a smaller number of broader advertisements. In plain language, it lets a router describe a group of networks with one shorter, more general route instead of announcing each one individually. This can reduce routing-table size and improve scalability. It can also reduce the amount of routing information that must be exchanged across certain boundaries.

The wrong answers often confuse summarization with default routing or encryption. The two correct statements are the ones that preserve its aggregation and scaling purpose.

Answer

It forces every router to use only a default route.

Answer

It is the same thing as PAT overload.

Answer

It automatically encrypts routing updates.

Question 10

Which two statements accurately describe why BGP is often relevant at an Internet or multi-provider edge?

Accepted Answer

It is associated with routing between autonomous systems.. BGP is often relevant at the edge because it is associated with route exchange between autonomous systems and large external routing domains. In practical terms, this makes it a natural protocol to discuss where organizations connect to providers or exchange external reachability. It is not just another interior campus protocol.

The question is about conceptual fit, not deep BGP attribute tuning.

Answer

It is mainly used to replace STP on access switches.

Answer

It is required before DHCP relay can function.

Answer

It is the protocol used by CAPWAP for AP discovery.

Question 11

You 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.

Accepted Answer

Configure R1's G0/0 with IP 192.168.1.1/24 and add a static route to 203.0.113.1/32 via 192.168.1.2. Configure R1's G0/1 with IPv6 address 2001:db8:acad:2::/64 eui-64.. The ping to R2's loopback fails because R1's G0/0 is configured with a /24 mask, but the network should be /24 (which is correct), but the loopback is on a different subnet (203.0.113.0/24 vs 192.168.1.0/24). Actually the issue is that R1 has no route to 203.0.113.1. The solution is to add a static route on R1 pointing to R2's G0/0 IP. For IPv6, R1's EUI-64 address is on the wrong subnet (2001:db8:acad:1::/64) but R3 is on 2001:db8:acad:2::/64. The fix is to change the IPv6 address on R1's G0/1 to 2001:db8:acad:2::/64 eui-64. Then add an IPv6 static route if needed (but R1 and R3 are directly connected, so after fixing the subnet, ping should work).

Answer

Configure R1's G0/0 with IP 192.168.1.1/24 and add a static route to 203.0.113.0/24 via 192.168.1.2. Configure R1's G0/1 with IPv6 address 2001:db8:acad:1::/64 eui-64.

Answer

Configure R1's G0/0 with IP 192.168.1.1/24 and add a static route to 203.0.113.1/32 via 192.168.1.2. Configure R1's G0/1 with IPv6 address 2001:db8:acad:2::1/64.

Answer

Configure R1's G0/0 with IP 192.168.1.1/24 and add a static route to 203.0.113.1/32 via 192.168.1.2. Configure R1's G0/1 with IPv6 address 2001:db8:acad:1::/64 eui-64.

Question 12

Users can reach a server by IP address but not by hostname. Which service should be checked first?

Accepted Answer

DNS. If the server is reachable by IP but not by name, the likely issue is name resolution, which points to DNS.

Answer

NTP

Answer

QoS

Answer

HSRP

Question 13

Which traffic type is typically most sensitive to delay and jitter and is commonly prioritized with QoS?

Accepted Answer

Voice traffic. Voice traffic is highly sensitive to delay, jitter, and packet loss, so it is commonly prioritized in QoS policies.

Answer

Bulk backup traffic

Answer

Email attachments

Answer

Operating system updates

Question 14

A host sends a packet larger than the outgoing interface MTU, and the IPv4 header has the Don't Fragment bit set.

What will a router do with the packet?

Accepted Answer

Drop it and typically return an ICMP message indicating fragmentation is needed. The router drops the packet because the packet is too large for the next link and the sender has explicitly said the packet must not be fragmented. In IPv4, the Don't Fragment bit tells routers not to break the packet into smaller pieces. If the outgoing interface MTU is smaller than the packet size, the router cannot legally forward it as-is and cannot fragment it, so the normal result is to drop the packet and usually send back an ICMP unreachable message indicating that fragmentation is needed. In plain terms, the router is telling the sender, 'This packet is too big for the path you chose, and you told me I am not allowed to split it.' This behavior is central to path MTU discovery.

Answer

Fragment it anyway and forward the pieces

Answer

Translate it to IPv6 and forward it

Answer

Broadcast it so another router can handle fragmentation

Question 15

A router is configured as follows:

interface g0/1
 ip address 172.16.1.1 255.255.255.0
 ip helper-address 10.20.20.10

Hosts on 172.16.1.0/24 are not receiving addresses from the DHCP server at 10.20.20.10. The server is reachable by ping from the router.

What is the purpose of the ip helper-address command in this scenario?

Accepted Answer

It forwards certain UDP broadcasts, including DHCP requests, to a remote server. The ip helper-address command exists to solve a broadcast-boundary problem. DHCP clients begin by sending broadcast traffic because they do not yet have a valid IP configuration. Routers normally do not forward broadcasts between subnets, so if the DHCP server lives on a different network, the client request would stop at the router. The helper-address function listens for that local broadcast and relays it as unicast traffic to the remote DHCP server. In plain language, it lets a client on one VLAN ask a DHCP server on another VLAN for an address. The command is not a routing statement and it is not a DNS feature. It is a relay mechanism for broadcast-based UDP services such as DHCP.

Answer

It converts DHCP unicast replies into broadcasts on the client segment

Answer

It provides DNS resolution for DHCP clients before they receive an address

Answer

It creates a static route to the DHCP server