CCNA IP Routing Practice Test 10 — 15 Questions

Question 1

A route to 192.168.1.0/24 appears in the routing table from OSPF, but a more specific static route to 192.168.1.128/25 is also configured. Which route is used for traffic to 192.168.1.200?

Accepted Answer

The static /25 route. The static /25 route is used because longest-prefix match prefers the most specific matching route. In plain language, even though the OSPF /24 route covers the destination, the /25 static route covers a narrower range and therefore wins for addresses inside that upper half of the subnet.

The router does not begin by asking which protocol is more trusted unless the prefix lengths are equal among the matching routes.

Answer

The OSPF /24 route

Answer

Both routes automatically load-balance

Answer

Neither route because the network overlaps

Question 2

Which two statements accurately describe OSPF route selection or behavior at the CCNA level?

Accepted Answer

OSPF uses cost as its metric for choosing paths within OSPF.. OSPF uses cost as its metric for path selection within the protocol, and OSPF routes are compared against other route sources using administrative distance when cross-protocol decisions are needed. OSPF supports equal-cost multi-path (ECMP), meaning it can install multiple equal-cost paths to the same destination, so option E is incorrect. The wrong answers confuse cost with administrative distance, treat process IDs as globally significant, or incorrectly direct cross-protocol metric comparisons.

Answer

OSPF compares its metric directly against EIGRP metrics across protocols.

Answer

OSPF process IDs must match between all neighboring routers.

Answer

OSPF can never install equal-cost paths.

Question 3

Why is route summarization often useful at distribution or area boundaries in larger networks?

Accepted Answer

It reduces the number of route advertisements by combining multiple specific prefixes. Route summarization is useful there because it reduces the number of specific prefixes that must be advertised upstream or across boundaries. In plain language, instead of sending many small route entries, the network can often advertise one broader summary that represents them collectively. This helps control routing-table growth and can make the design more scalable and easier to manage.

Summarization does not eliminate the need for routing detail inside the local area, but it can simplify what needs to be shared outward. That is why it is especially valuable at aggregation points such as distribution layers or area boundaries.

Answer

It forces all users into the same VLAN

Answer

It automatically encrypts routing protocols

Answer

It removes the need for IP addressing

Question 4

A router receives two routes to 10.50.0.0/16: one from OSPF and one static route with an administrative distance of 90. Which route is installed by default?

Accepted Answer

The static route, because its administrative distance is lower than OSPF's. By default, the static route with administrative distance 90 is installed because it is preferred over the OSPF route with default administrative distance 110. In plain language, the router is being told that the manually configured route is more trustworthy than the OSPF-learned one, so it chooses the static path first. The protocol type alone does not decide the outcome. Administrative distance is the key comparison when two different route sources offer the same destination prefix length.

This is a classic routing-selection question because many learners incorrectly assume OSPF always wins over static routes unless the static route uses the default administrative distance. Once the static route is given a value lower than OSPF’s 110, it becomes the preferred path unless a more specific route exists elsewhere.

Answer

The OSPF route, because dynamic routes always override static routes

Answer

Both routes, because equal destination networks always load-balance

Answer

Neither route, because the destinations overlap

Question 5

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 6

Two routers are in the same OSPF area and on the same subnet, but they do not form an adjacency. One interface uses a hello interval of 10 seconds and the other uses 5 seconds. What is the most likely cause?

Accepted Answer

The OSPF hello timers do not match.. An OSPF timer mismatch is the most likely cause. In plain language, the routers are trying to discover each other, but they are speaking on different timing expectations. OSPF neighbors on the same segment must agree on certain parameters before they trust each other enough to form an adjacency, and the hello and dead timers are among those critical values.

This is a very common OSPF troubleshooting issue because the interfaces may still be reachable with ping and may even appear correctly addressed and placed in the same area. But OSPF is stricter than simple IP reachability. If the hello interval does not match, the adjacency usually fails before it becomes fully operational.

Answer

The routers need matching hostnames.

Answer

The subnet must be changed to /24 before OSPF can work.

Answer

The routers must both use static routes first.

Question 7

An OSPF-enabled router has two paths to the same destination network, and both paths have the same OSPF cost. What is the most likely default behavior?

Accepted Answer

Install both routes and use equal-cost multipath forwarding. When OSPF learns two equally good paths to the same destination, the router can install both and perform equal-cost multipath forwarding. In plain language, the router does not have to throw one away simply because there are two valid answers. If the routes are truly equal from OSPF’s perspective, it can use both paths to improve resilience and share traffic.

This is a classic routing behavior question because many candidates assume the router must always choose only one best path. In reality, equal-cost multipath is a normal feature in many routing environments. The key is that the paths must be equally good according to the protocol’s metric logic.

Answer

Discard both routes because OSPF cannot handle duplicates

Answer

Always keep only the route learned first

Answer

Replace both routes with a default route

Question 8

A static default route is configured with an administrative distance of 250. What is the most likely design intention?

Accepted Answer

To keep the route as a backup of last resort behind normal learned routes. The design intention is to make the static default route a very low-priority backup path. In plain language, the administrator wants the route to exist only as a last resort behind almost any normal learned path. By assigning such a high administrative distance, the route stays out of the active table unless better routes disappear.

This is a floating-static design concept. The route is not meant to be primary. It is intentionally configured to sit in reserve and become relevant only during failure conditions or severe loss of normal routing information.

Answer

To make the route override all dynamic routing immediately

Answer

To disable default routing entirely

Answer

To convert the default route into a host route

Question 9

A packet is destined for 192.168.40.130. The routing table contains 192.168.40.0/24, 192.168.40.128/25, and 0.0.0.0/0. Which route is used?

Accepted Answer

192.168.40.128/25. The /25 route is used because it is the most specific matching prefix. In plain language, even though the /24 and the default route also technically match, the router prefers the entry that most precisely describes the destination range. Since 192.168.40.130 falls inside 192.168.40.128/25, that route wins under longest-prefix match.

This is a classic routing-table interpretation pattern. The router does not start with the default route when more specific routes exist, and it does not choose the /24 simply because it is familiar. Specificity comes first.

Answer

192.168.40.0/24

Answer

0.0.0.0/0

Answer

No route can be used because the entries overlap

Question 10

Which two statements accurately describe OSPF passive interfaces?

Accepted Answer

It prevents OSPF from sending hello packets on that interface.. An OSPF passive interface stops hello packet exchange on that interface while still allowing the connected network to be advertised into OSPF through other active adjacencies. In plain language, it tells the router not to try to form neighbors on that interface, but not to forget that the network exists. This is very useful on user-facing or stub-like interfaces where no routing neighbor should appear.

The wrong answers often treat passive as if it disables OSPF globally or removes the network completely. The two correct answers are the ones that preserve the suppression of adjacency on that interface and the continued advertisement of the connected network.

Answer

It changes OSPF into a static route on that interface.

Answer

It forces the interface to become the router ID.

Answer

It disables OSPF on every interface in the router automatically.

Question 11

Two routers are directly connected over IPv6 and should form an OSPFv3 adjacency, but they do not. Link-local addressing is present on both interfaces. Which issue is most likely to prevent the adjacency?

Accepted Answer

The interfaces are assigned to different OSPFv3 areas.. An area mismatch is a strong and direct explanation. In plain language, even though the routers can have valid IPv6 addressing and proper link-local communication on the interface, OSPFv3 still requires the two ends of the shared segment to agree on the area context for the adjacency. If one side places the interface in one area and the other side places it in another, the routers will not treat each other as valid neighbors.

This is very similar in principle to OSPF for IPv4. Link-local addressing matters in OSPFv3, but the protocol still enforces key neighbor-formation checks. The correct answer is the one that focuses on a required protocol match rather than on a vague issue like hostname or cable color.

Answer

The routers need matching hostnames before OSPFv3 can start.

Answer

IPv6 requires a /64 only for routing protocols to function.

Answer

OSPFv3 cannot run on directly connected interfaces.

Question 12

A router has a default route and a specific route to 203.0.113.0/24. Which route is used for traffic to 203.0.113.25?

Accepted Answer

The specific route to 203.0.113.0/24. The specific route to 203.0.113.0/24 is used because it is a more specific match than the default route. In plain language, even though the default route could technically match almost anything, the router always prefers a route that more precisely describes the destination network. Since 203.0.113.25 is inside 203.0.113.0/24, that route wins under longest-prefix match.

This is one of the most basic routing-table interpretation rules. The default route remains important as a fallback, but it is not chosen when a more specific valid route exists.

Answer

The default route

Answer

Both routes are always load-balanced

Answer

Neither route because defaults cannot coexist with specific routes

Question 13

Two routers are directly connected and running OSPF. Their IP addresses and hello timers match, but they still do not become neighbors. One side is configured for area 0 and the other for area 1 on the shared link. What is the most likely cause?

Accepted Answer

The interfaces are in different OSPF areas on the shared link.. An OSPF area mismatch is the most likely cause. In plain language, the routers may be physically connected and able to exchange packets, but OSPF still requires that both sides agree on the area associated with the shared segment. If one interface belongs to area 0 and the other belongs to area 1, the routers do not view the segment in the same OSPF context and the adjacency fails.

This is a classic CCNA troubleshooting case because the addressing can look perfect while the protocol still refuses to form a neighbor relationship. OSPF is strict about several interface-level values, and the area assignment is one of the most important.

Answer

The routers need identical hostnames.

Answer

The link must be converted to a trunk.

Answer

The routers must use static routes first.

Question 14

A routing table contains these entries for the same destination space: 10.1.0.0/16, 10.1.10.0/24, and 0.0.0.0/0. Which route is used for traffic to 10.1.10.44?

Accepted Answer

10.1.10.0/24. The 10.1.10.0/24 route is used because it is the most specific matching prefix. In plain language, even though the /16 route and the default route could also match, the /24 route describes the destination range more precisely. Longest-prefix match therefore selects the /24 entry.

This is a foundational route-selection rule. The default route remains important as a fallback, but it is not used when more specific routes exist. Likewise, the /16 route is less specific than the /24, so it loses for this destination.

Answer

10.1.0.0/16

Answer

0.0.0.0/0

Answer

No route, because the entries overlap

Question 15

A router learns 172.16.0.0/16 from OSPF and 172.16.10.0/24 from a static route. Which route is used for traffic to 172.16.10.55?

Accepted Answer

The static /24 route. The static /24 route is used because it is more specific than the OSPF /16 route. In plain language, even though OSPF is a dynamic source and the /16 covers the destination broadly, the router prefers the entry that describes the exact destination range more precisely. Since 172.16.10.55 falls within 172.16.10.0/24, that route wins under longest-prefix match.

This is a classic example of route specificity taking priority before broader route-source comparisons would matter between equal prefix lengths.

Answer

The OSPF /16 route

Answer

The default route

Answer

Neither route because the prefixes overlap