Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
Exhibit
R1# show ip route C 172.18.9.0/24 is directly connected, GigabitEthernet0/1 S 172.18.0.0/16 [1/0] via 192.0.2.2 Destination being tested: 172.18.9.10
Based on the exhibit, why is the static route not being used for 172.18.9.10?
Answer choices
Why each option matters
Good practice is not just finding the correct option. The wrong answers often show the exact trap the exam wants you to fall into.
A
Best answer
Because the connected /24 route is more specific than the static /16 route.
This is correct because longest-prefix match causes the connected /24 to be used for that destination.
B
Distractor review
Because static routes are never used when a connected network exists anywhere in the table.
This is wrong because static routes may still be used for destinations not covered by the connected route.
C
Distractor review
Because connected routes always have administrative distance 255.
This is wrong because connected routes are not explained by that statement and the real issue is specificity.
D
Distractor review
Because static routes work only for default routing.
This is wrong because static routes can absolutely be used for specific prefixes.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A common exam trap is assuming that static routes are always preferred over connected routes or that connected routes have a higher administrative distance. Candidates might overlook the longest-prefix match rule and focus only on administrative distance or route type. This leads to the incorrect conclusion that the static /16 route should be used for 172.18.9.10, ignoring that the connected /24 route is more specific and therefore preferred. Misunderstanding this concept causes errors in interpreting routing tables and route selection behavior.
Technical deep dive
How to think about this question
Routing decisions in Cisco networks rely heavily on the principle of longest-prefix match, which means the router selects the route with the most specific subnet mask that matches the destination IP address. In this scenario, the destination IP 172.18.9.10 falls within both a connected /24 network and a static /16 route. The connected route has a subnet mask of 255.255.255.0 (/24), which is more specific than the static route's 255.255.0.0 (/16). Therefore, the router prefers the connected route because it provides a more precise match to the destination address. The routing table lookup process first evaluates prefix length before considering administrative distance or route source. Even though static routes typically have a lower administrative distance than some dynamic routes, the longest-prefix match rule takes precedence. This means that if a connected route covers a smaller subnet that includes the destination IP, it will be chosen over a broader static route. Administrative distance is only considered when multiple routes have the same prefix length. A common exam trap is misunderstanding how route specificity interacts with administrative distance. Candidates might incorrectly assume that static routes are always preferred over connected routes or that connected routes have a higher administrative distance. In reality, connected routes have the lowest administrative distance (0), but the key factor here is the prefix length. Practically, this behavior ensures traffic is routed via the most precise path available, which optimizes network performance and reduces unnecessary routing overhead.
KKey Concepts to Remember
- Longest-prefix match causes routers to select the route with the most specific subnet mask that matches the destination IP address.
- Connected routes have an administrative distance of 0, making them preferred over static routes if prefix lengths are equal.
- Static routes can be used for broad or specific prefixes but are overridden by more specific connected routes in the routing table.
- Routing table lookup first compares prefix length before considering administrative distance or route source.
- A connected route covering a /24 subnet will be preferred over a static route covering a /16 subnet for a destination within the /24 range.
- Administrative distance is only used to break ties when multiple routes have the same prefix length.
- Static routes are not limited to default routing and can specify any prefix length.
- Routing decisions prioritize specificity to optimize path selection and network efficiency.
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
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More questions from this exam
Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.
Question 1
A router learns the same prefix from both OSPF and EIGRP. Which route is installed by default?
Question 2
A router shows this output: R1#show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 10.1.1.2 1 FULL/DR 00:00:34 192.168.12.2 GigabitEthernet0/0 10.1.1.3 1 2WAY/DROTHER 00:00:39 192.168.12.3 GigabitEthernet0/0 Which statement is correct?
Question 3
What is the OSPF metric called?
Question 4
A non-root switch has two uplinks toward the root bridge. One path has a lower total STP cost than the other. What role will the lower-cost uplink have?
Question 5
A router interface applies this ACL inbound: 10 deny tcp any any eq 80 20 permit ip any any A user reports that web browsing to a server by IP address fails, but ping works. Which statement best explains the behavior?
Question 6
A router learns route 198.51.100.0/24 from OSPF with AD 110 and also has a static route to the same prefix configured with AD 150. Which route is installed?
FAQ
Questions learners often ask
What does this 200-301 question test?
Longest-prefix match causes routers to select the route with the most specific subnet mask that matches the destination IP address.
What is the correct answer to this question?
The correct answer is: Because the connected /24 route is more specific than the static /16 route. — The static route is not being used because the connected route is the more specific match. In practical terms, route selection starts with prefix specificity. The static route covers a broad /16, but the destination 172.18.9.10 also falls inside a connected /24. The /24 wins because it is more specific. This is a classic routing interpretation question because it tests whether you apply longest-prefix logic before thinking about route source preference.
What should I do if I get this 200-301 question wrong?
Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.
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