Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
A multilayer switch has SVIs for VLAN 10 and VLAN 20. Hosts in both VLANs can reach their local SVI, but they cannot reach each other. Which additional configuration is most likely required?
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
Enable `ip routing` on the multilayer switch.
This is correct because the switch needs Layer 3 routing enabled to forward traffic between SVIs.
B
Distractor review
Convert all access ports into trunks.
This is wrong because host-facing ports do not all need to be trunks for inter-VLAN routing to work.
C
Distractor review
Make both VLANs use the same IP subnet.
This is wrong because separate VLANs normally use separate IP networks for routed inter-VLAN communication.
D
Distractor review
Disable spanning tree on both VLANs.
This is wrong because STP is not the missing requirement for routing between SVIs.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A frequent exam trap is assuming that SVIs alone enable inter-VLAN routing. Candidates often configure SVIs with IP addresses and expect hosts in different VLANs to communicate without enabling 'ip routing'. This mistake leads to a scenario where hosts can reach their local gateway but cannot communicate across VLANs. The trap exploits the misconception that Layer 3 interfaces automatically provide routing functionality, when in fact the routing process must be explicitly activated on a multilayer switch.
Technical deep dive
How to think about this question
A multilayer switch combines Layer 2 switching and Layer 3 routing capabilities within a single device. It uses Switched Virtual Interfaces (SVIs) to provide Layer 3 gateway interfaces for VLANs, enabling hosts within each VLAN to communicate with their local subnet. However, SVIs alone do not enable inter-VLAN routing; the device must have IP routing explicitly enabled to forward packets between different VLANs. Without this, the switch treats each VLAN as isolated, allowing local communication but blocking traffic between VLANs. The key configuration step to enable inter-VLAN routing on a multilayer switch is the activation of the 'ip routing' command. This command turns on the Layer 3 routing engine, allowing the switch to route traffic between SVIs associated with different VLANs. When 'ip routing' is enabled, the switch builds a routing table and forwards packets between VLANs based on their IP addresses. This is essential for hosts in separate VLANs to communicate, as VLANs represent distinct IP subnets. A common exam trap is assuming that creating SVIs automatically enables routing between VLANs. Many candidates mistakenly believe that simply assigning IP addresses to SVIs is sufficient. In reality, without the 'ip routing' command, the multilayer switch cannot route traffic between VLANs, causing inter-VLAN communication failure. Practically, this means hosts can ping their default gateway SVI but cannot reach hosts in other VLANs until routing is enabled.
KKey Concepts to Remember
- A multilayer switch uses SVIs to provide Layer 3 gateway interfaces for each VLAN, enabling local subnet communication.
- The 'ip routing' command must be enabled on a multilayer switch to activate Layer 3 routing between SVIs and VLANs.
- Without 'ip routing', SVIs respond locally but do not forward traffic between VLANs, preventing inter-VLAN communication.
- Each VLAN typically uses a unique IP subnet to separate broadcast domains and enable routing between VLANs.
- Access ports connect hosts to a single VLAN and do not need to be trunk ports for inter-VLAN routing to function.
- Spanning Tree Protocol (STP) manages Layer 2 loops and does not affect Layer 3 routing between VLANs on a multilayer switch.
- Enabling 'ip routing' causes the multilayer switch to build a routing table and forward packets based on IP addresses.
- A common mistake is assuming SVIs alone enable routing; explicit activation of routing is required for inter-VLAN traffic.
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 multilayer switch uses SVIs to provide Layer 3 gateway interfaces for each VLAN, enabling local subnet communication.
What is the correct answer to this question?
The correct answer is: Enable `ip routing` on the multilayer switch. — The most likely missing configuration is `ip routing`. In practical terms, the switch already has Layer 3 gateway interfaces for the VLANs, which is why hosts can reach their local SVI. But inter-VLAN communication still requires the switch to actually route between those VLAN interfaces. Without IP routing enabled, the SVIs can exist and respond locally without forwarding traffic between them. This is a classic multilayer-switch question because many learners assume that creating SVIs automatically enables inter-VLAN routing. It does not. The device must also be told to behave as a Layer 3 forwarding device across those VLAN interfaces.
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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