Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
A router has a static route to 10.20.20.0/24 and also has a default route. Which route is used for traffic to 10.20.20.8?
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
The static route to 10.20.20.0/24
This is correct because the /24 route matches the destination more specifically than the default route.
B
Distractor review
The default route
This is wrong because a more specific route exists.
C
Distractor review
Both routes are used equally
This is wrong because the more specific route is preferred.
D
Distractor review
Neither route is valid
This is wrong because the static route clearly matches the destination.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A frequent exam trap is assuming the default route is used whenever it exists, ignoring the presence of more specific static routes. This misunderstanding leads to incorrect answers because routers always prefer the route with the longest matching prefix, not the default route unless no other matches exist.
Technical deep dive
How to think about this question
In IP routing, routers use routing tables to determine the best path to forward packets toward their destination. Each route in the table has a destination network and a subnet mask, which defines the range of IP addresses covered. A static route is a manually configured route that specifies a particular destination network and the next-hop IP or exit interface. A default route, often represented as 0.0.0.0/0, acts as a catch-all route for any destination not explicitly listed in the routing table. When a router receives a packet, it searches for the most specific route that matches the destination IP address, prioritizing longer prefix matches over shorter ones. The router uses the longest prefix match rule to select the route that most precisely matches the destination IP address. In this case, the static route to 10.20.20.0/24 covers all IP addresses from 10.20.20.0 to 10.20.20.255, including 10.20.20.8. The default route covers all IP addresses but with a prefix length of zero, making it the least specific. Therefore, the router forwards traffic to 10.20.20.8 using the static route because it has a more specific subnet mask (/24) than the default route (/0). This behavior ensures efficient and accurate routing decisions. A common exam trap is assuming the default route is always used when multiple routes exist. Candidates may mistakenly select the default route because it is a known fallback path. However, the router always prefers the most specific route available. In practical networking, this prevents unnecessary use of the default route and ensures traffic is routed optimally. Understanding this routing decision process is critical for CCNA candidates to correctly interpret routing tables and troubleshoot routing issues effectively.
KKey Concepts to Remember
- A router uses the longest prefix match rule to select the most specific route for a given destination IP address.
- Static routes are manually configured and provide explicit paths to specific networks, overriding less specific routes.
- The default route (0.0.0.0/0) acts as a route of last resort when no other more specific routes exist.
- Routers prefer routes with longer subnet masks because they match destination addresses more precisely.
- When multiple routes exist, the router chooses the route with the most specific subnet mask before considering administrative distance or metrics.
- A static route to 10.20.20.0/24 covers all IP addresses in that subnet, including 10.20.20.8, making it more specific than the default route.
- The default route is only used if no other routes in the routing table match the destination IP address.
- Understanding route specificity is essential for interpreting routing behavior and troubleshooting connectivity issues in Cisco networks.
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?
A router uses the longest prefix match rule to select the most specific route for a given destination IP address.
What is the correct answer to this question?
The correct answer is: The static route to 10.20.20.0/24 — The static route to 10.20.20.0/24 is used because it is more specific than the default route. In practical terms, the router always chooses the route that most precisely matches the destination before falling back to the default route. This question reinforces the idea that the default route is a route of last resort, not a preferred choice when a better match already exists.
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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