Question 1mediummatching
Full question →Match each trunking or switchport term to its most accurate description.
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mediummatchingObjective-mapped
Match each trunking or switchport term to its most accurate description.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A frequent exam trap is confusing the native VLAN with the access VLAN or assuming that access ports tag frames. Candidates often mistakenly believe that access ports carry multiple VLANs or that the native VLAN tags frames on a trunk. This misunderstanding leads to misconfigurations where untagged traffic is mishandled or VLAN mismatches occur. Another trap is neglecting to synchronize the native VLAN on both trunk endpoints, causing traffic to leak into unintended VLANs. Remember, the native VLAN carries untagged frames only on trunks, while access ports carry untagged frames for a single VLAN without tagging.
Technical deep dive
How to think about this question
Trunking is a fundamental concept in VLAN implementation that allows multiple VLANs to share a single physical link between switches. This is achieved by tagging Ethernet frames with VLAN identifiers using the IEEE 802.1Q standard. The trunk port carries traffic for all VLANs allowed on the link, preserving VLAN separation across the network. In contrast, an access port is assigned to a single VLAN and forwards untagged frames to connected end devices, which do not understand VLAN tags. The native VLAN is a special VLAN on 802.1Q trunks that carries untagged traffic. Frames belonging to the native VLAN are sent without VLAN tags, which helps maintain backward compatibility with devices that do not support VLAN tagging. However, the native VLAN must be configured identically on both ends of the trunk link to prevent VLAN mismatches that can cause traffic to be misrouted or dropped. The allowed VLAN list further controls which VLANs are permitted to traverse a trunk, enabling network administrators to limit broadcast domains and improve security by blocking unnecessary VLAN traffic. A common exam trap involves confusing the native VLAN with the access VLAN or misunderstanding the role of VLAN tagging on access ports. For example, assuming that access ports tag frames or that the native VLAN carries tagged traffic can lead to incorrect configurations and connectivity issues. Additionally, leaving the native VLAN as the default VLAN 1 can expose the network to VLAN hopping attacks. Practically, network engineers often change the native VLAN to an unused VLAN and carefully manage allowed VLAN lists to maintain secure and efficient VLAN trunking environments.
KKey Concepts to Remember
- A trunk port carries traffic for multiple VLANs simultaneously by tagging frames with 802.1Q VLAN identifiers to maintain VLAN separation across switches.
- An access port forwards traffic for a single VLAN and does not tag frames, making it suitable for connecting end devices like PCs or printers.
- The native VLAN on an 802.1Q trunk port carries untagged frames and must be consistent on both ends to avoid VLAN mismatches and security risks.
- The allowed VLAN list on a trunk port restricts which VLANs can traverse the trunk link, enhancing security and reducing unnecessary traffic.
- Switches use trunking to extend VLANs across multiple devices, enabling devices in the same VLAN but on different switches to communicate.
- Misconfiguring native VLANs or allowed VLAN lists can cause VLAN hopping, traffic leaks, or connectivity issues between VLANs.
- Cisco switches default the native VLAN to VLAN 1, but best practice is to change it to an unused VLAN to improve security.
- Access ports do not tag frames, so any VLAN tagging configuration on an access port is ignored or causes errors.
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 trunk port carries traffic for multiple VLANs simultaneously by tagging frames with 802.1Q VLAN identifiers to maintain VLAN separation across switches.
What exam trap should I watch out for?
Common exam trap: answer the scenario, not the keyword: A frequent exam trap is confusing the native VLAN with the access VLAN or assuming that access ports tag frames. Candidates often mistakenly believe that access ports carry multiple VLANs or that the native VLAN tags frames on a trunk. This misunderstanding leads to misconfigurations where untagged traffic is mishandled or VLAN mismatches occur. Another trap is neglecting to synchronize the native VLAN on both trunk endpoints, causing traffic to leak into unintended VLANs. Remember, the native VLAN carries untagged frames only on trunks, while access ports carry untagged frames for a single VLAN without tagging.
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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