Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
Exhibit
R1# show ip route O 10.1.1.0/24 [110/20] via 192.0.2.2 S 10.1.1.64/26 [1/0] via 192.0.2.6 O 10.1.0.0/16 [110/30] via 192.0.2.10 S* 0.0.0.0/0 [1/0] via 198.51.100.1 Destination being tested: 10.1.1.70
Based on the exhibit, which route will be used for destination 10.1.1.70?
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 10.1.1.64/26
This is correct because 10.1.1.70 matches the more specific /26 route.
B
Distractor review
The OSPF route to 10.1.1.0/24
This is wrong because the /24 route is less specific than the /26.
C
Distractor review
The OSPF route to 10.1.0.0/16
This is wrong because the /16 route is even less specific.
D
Distractor review
The default route
This is wrong because a more specific matching route exists.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A frequent exam trap is to incorrectly assume that dynamic routing protocols like OSPF always override static routes or that administrative distance alone determines the chosen route. Candidates might see multiple routes to the destination and pick the OSPF route with a broader subnet mask, ignoring that the static route has a longer prefix match. This mistake overlooks the fundamental Cisco routing rule that longest prefix match takes precedence over administrative distance when multiple routes exist. Misreading subnet masks or ignoring prefix specificity leads to selecting less optimal or incorrect routes in the exam scenario.
Technical deep dive
How to think about this question
Routing decisions in Cisco networks rely heavily on the concept 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 10.1.1.70 falls within multiple routes: a static route to 10.1.1.64/26, an OSPF route to 10.1.1.0/24, and an OSPF route to 10.1.0.0/16. The /26 subnet mask is more specific than /24 and /16, so the router prefers this route regardless of the routing protocol or administrative distance, assuming the static route is valid and reachable. The routing table lookup process begins by filtering routes that match the destination IP address and then comparing their subnet masks to find the longest prefix match. Cisco routers prioritize routes with the longest subnet mask because they represent a smaller, more precise network segment. Even if the static route and OSPF routes coexist, the static route with the /26 mask is chosen because it narrows down the destination network more accurately than the broader OSPF routes. A common exam trap is to assume that dynamic routing protocols like OSPF always take precedence over static routes or that administrative distance alone determines the route selection without considering prefix length. In reality, the longest prefix match rule is the primary factor in route selection. Practically, this means network engineers must carefully design subnetting and route summarization to avoid unintended routing behaviors and ensure traffic follows the most efficient path.
KKey Concepts to Remember
- Cisco routers select the route with the longest matching prefix to forward packets to the destination IP address.
- Static routes with more specific subnet masks override less specific dynamic routing protocol routes when both match the destination.
- OSPF advertises routes with varying prefix lengths, but routers prefer the most specific subnet mask regardless of routing protocol.
- Routing decisions prioritize prefix length before considering administrative distance or metric values in Cisco devices.
- A route to 10.1.1.64/26 is more specific and preferred over routes to 10.1.1.0/24 and 10.1.0.0/16 for destination 10.1.1.70.
- Default routes are only used when no more specific matching route exists in the routing table.
- Subnetting precision directly impacts route selection and traffic forwarding in Cisco routing environments.
- Understanding longest prefix match helps avoid misinterpretation of routing table entries and ensures correct path selection.
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?
Cisco routers select the route with the longest matching prefix to forward packets to the destination IP address.
What is the correct answer to this question?
The correct answer is: The static route to 10.1.1.64/26 — The route used will be the one with the longest matching prefix. In practical terms, 10.1.1.70 falls inside 10.1.1.64/26, and that prefix is more specific than both 10.1.1.0/24 and 10.1.0.0/16. Route selection begins with specificity, so the /26 route wins regardless of the broader alternatives. This is a clean simulation-style routing-table interpretation question and very close to real exam thinking.
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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