CCNA IP Routing Practice Test 13 — 15 Questions

Question 1

Exhibit: R1 has learned 10.50.0.0/24 through OSPF and also has a floating static route to the same prefix with administrative distance 130. Which route is installed while OSPF is healthy?

Accepted Answer

The OSPF route because its administrative distance is lower than the floating static route. A floating static route is meant to stay out of the table until the preferred route disappears. OSPF has administrative distance 110, which is lower than the static route AD 130, so the OSPF route is installed while the OSPF path is still present.

Answer

The static route because static routes always win over dynamic routes

Answer

Both routes because the prefix length matches

Answer

Neither route until equal-cost load balancing is configured

Question 2

R3 has the static route 'ip route 172.20.8.0 255.255.255.0 192.168.1.1'. Packets destined for 172.20.8.0/24 are being dropped. What is the most likely cause?

Accepted Answer

The next-hop address is not reachable from R3. A static route can only work if the next-hop address is reachable. If the next hop is down or missing from the routing table, the route cannot forward traffic successfully.

Answer

The destination network mask should be /16 instead of /24

Answer

Static routes require an outbound access list

Answer

The route must use administrative distance 255

Question 3

A network engineer wants a static route to be used only when the OSPF-learned route disappears. Which configuration approach meets that goal?

Accepted Answer

Use a static route with administrative distance higher than 110. That is a floating static route. You configure the static route with an administrative distance higher than the OSPF route so it stays in reserve until the dynamic path is lost.

Answer

Use a static route with administrative distance 1

Answer

Use a static route with metric 0

Answer

Redistribute the static route into OSPF

Question 4

Exhibit: R1 shows an OSPF neighbor stuck in EXSTART with R2 on a serial link. What is the most likely cause?

Accepted Answer

An interface MTU mismatch between the routers. When two OSPF routers stay in EXSTART, the first thing to suspect is an MTU mismatch. They can discover each other, but database exchange does not complete because the DBD packets do not agree on interface MTU.

Answer

An OSPF area mismatch

Answer

A duplicate router ID on R1 and R2

Answer

A missing default route on R2

Question 5

Which OSPF component is used to identify routers uniquely inside an OSPF domain?

Accepted Answer

Router ID. The router ID is the unique identifier OSPF uses for each router. It is not the same thing as the process ID, which is locally significant only.

Answer

Area ID

Answer

Hello timer

Answer

Wildcard mask

Question 6

R1 has routes to 172.16.10.0/24 from multiple sources. Which route will be installed?

Accepted Answer

The EIGRP internal route. Routers compare route source trust first using administrative distance. EIGRP internal routes have an AD of 90, which is lower than OSPF (110), RIP (120), and a static route with AD 95. Therefore, the EIGRP internal route is installed, regardless of metrics.

Answer

The OSPF route with metric 20

Answer

The RIP route because hop count is lowest

Answer

The static route with administrative distance 95

Question 7

Exhibit: R1 learns 192.168.50.0/24 from multiple sources. Which two statements are correct about the route that will be installed in the routing table?

Accepted Answer

The static route is preferred because its administrative distance is lowest. The router chooses the route with the lowest administrative distance first. If administrative distance ties, it then compares the metric within that routing source. In this case the static route wins because AD 1 beats eBGP 20, OSPF 110, and RIP 120.

Answer

The OSPF route is preferred because cost 20 is lower than RIP metric 2

Answer

The eBGP route would win over the static route because BGP is more dynamic

Answer

RIP would be chosen before OSPF because hop count is simpler

Question 8

Exhibit: A router has both an OSPF-learned default route and a floating static default route. Which route is currently active?

Accepted Answer

The OSPF default route, because AD 110 beats the floating static AD 150. A floating static route only takes over when its administrative distance is set higher than the preferred route and the preferred route disappears. The routing table shows the OSPF default because AD 110 is lower than the floating static AD 150.

Answer

The static route, because static routes always override dynamic routes

Answer

Both routes load-balance automatically

Answer

Neither route, because a default route cannot be learned by OSPF

Question 9

Exhibit: R1 can ping 10.1.23.2 but cannot ping 192.168.3.10 behind R3. The routing table on R1 lacks 192.168.3.0/24. What is the best next check?

Accepted Answer

Verify whether the remote LAN is being advertised into the routing process. Because the directly connected next router is reachable, the problem is likely missing routing information for the remote LAN. The best next check is whether R3 is advertising 192.168.3.0/24 or whether that network is present in the routing domain at all.

Answer

Replace the Ethernet cable between R1 and R2

Answer

Change the OSPF router ID on R1 immediately

Answer

Disable CEF so the route can be learned

Question 10

Exhibit: Consider the following ACL applied inbound on interface G0/0:

access-list 100 deny ip host 10.10.10.10 any
access-list 100 deny tcp any host 10.10.10.10 eq 23
access-list 100 permit ip any any

The intent is to block only Telnet (TCP port 23) to server 10.10.10.10 while permitting everything else. However, users cannot reach any service on that server. Why?

Accepted Answer

The deny ip statement blocks all traffic to the host before the Telnet-specific line is evaluated. ACLs are processed top-down, and the first match is applied. The first line denies all IP traffic to the host (any protocol, any port). This matches all packets destined for 10.10.10.10 before the Telnet-specific line is ever reached, effectively blocking every service, not just Telnet.

Answer

The ACL must be applied outbound, not inbound

Answer

Extended ACLs cannot match TCP port 23

Answer

Telnet uses UDP, so the ACE should reference udp

Question 11

Exhibit: An OSPFv2 adjacency between two routers on Ethernet is not forming. Which two mismatches would directly prevent the routers from becoming neighbors?

Accepted Answer

Different OSPF area assignments on the interfaces. On an OSPFv2 network, area mismatch and authentication mismatch both directly prevent adjacency formation. Mismatched timers (such as hello or dead intervals) also block adjacency on all network types, including Ethernet. In this scenario, the correct choices are area mismatch (A) and authentication mismatch (B).

Answer

Different hostnames on the routers

Answer

Different loopback addresses used for management

Answer

One router using SSH version 2

Question 12

Exhibit: A static route to 172.16.40.0/24 is configured, but traffic still follows the default route. Which two explanations are plausible?

Accepted Answer

The next hop for the static route may not be reachable. If a static route points to an unreachable next hop or the outgoing interface is down, the route may not be installed as usable. In that case the router can still use a less specific route such as the default route.

Answer

The default route always overrides more specific routes

Answer

Static routes require a metric lower than 1

Answer

The destination prefix must be configured under router ospf first

Question 13

A router has learned route 172.16.50.0/24 from OSPF with cost 20 and also has a static route to the same prefix with administrative distance 5. Which two statements are correct about route selection?

Accepted Answer

The static route is installed because it has the lower administrative distance. When the same prefix is learned from different routing sources, the router first compares administrative distance (AD). The static route with AD 5 wins over OSPF with AD 110, so option A is correct. Option C is correct because if the static route is removed, the OSPF route becomes the next best candidate and is installed. Option B is wrong since AD is compared before metrics like OSPF cost; a lower cost does not override a lower AD. Option D is wrong because only one route is installed per destination based on AD, not both.

Answer

The OSPF route is installed because cost 20 is lower than metric 0

Answer

Both routes are installed as equal-cost paths automatically

Question 14

A static default route is configured on R1 toward ISP-A, and a second default route toward ISP-B is configured with a higher administrative distance. Which two statements are correct during normal operation and after ISP-A failure?

Accepted Answer

The route through ISP-A is preferred during normal operation. This is a classic floating static design. The lower-AD default route is primary, and the higher-AD default waits in reserve.

Answer

Both defaults are always installed and used equally

Answer

The backup route is ignored permanently because only one default route can exist

Question 15

A network engineer needs a floating static route to back up an OSPF-learned route. Which two configurations are necessary for the static route to remain unused until OSPF fails?

Accepted Answer

Configure the static route with an administrative distance higher than 110. A floating static route requires an administrative distance higher than OSPF's default of 110 (option A) so that the static route is less preferred and remains inactive while OSPF is available. Additionally, the static route must point to a valid next-hop IP or exit interface (option B); without a valid next-hop, the route cannot be installed in the routing table and would never serve as a backup. Option C is incorrect because Cisco routers compare administrative distance before metric when routes come from different sources, so a lower metric cannot override the AD difference. Option D is wrong because a directly connected route (with no next-hop) would be treated as a connected route, not a static route, and would be preferred over OSPF due to its AD of 0, defeating the purpose of a floating backup.

Answer

Set the static route metric lower than the OSPF cost

Answer

Configure the route as directly connected with no next-hop information