Question 1easymultiple choice
Full question →easymultiple choiceObjective-mapped
Which cable type is commonly used to connect a switch to a router when using standard Ethernet interfaces on modern devices with auto-MDIX support?
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
Distractor review
Rollover cable
Rollover cables are typically used for console access, not data-plane Ethernet forwarding.
B
Best answer
Straight-through Ethernet cable
Correct. Straight-through is the standard answer for this connection type.
C
Distractor review
Serial DCE cable
Serial DCE cables are used for serial WAN links, not Ethernet switch-to-router links.
D
Distractor review
Fiber patch cable only
Fiber may be used in some environments, but not only fiber and not as the default answer here.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A frequent exam trap is selecting a crossover cable for connecting a switch to a router, based on outdated knowledge that crossover cables are needed between similar device types. Modern Cisco devices with auto-MDIX support eliminate this requirement by automatically adjusting pinouts, making straight-through cables the standard choice. Another pitfall is confusing rollover cables, which are only for console management connections, not data-plane Ethernet links. Candidates may also mistakenly consider serial DCE cables, which are irrelevant for Ethernet interfaces. Recognizing the specific use cases for each cable type prevents these common errors.
Technical deep dive
How to think about this question
Ethernet cabling is fundamental to establishing physical connectivity in Cisco networks. A straight-through Ethernet cable has identical wiring on both ends, connecting pins 1 to 1 and 2 to 2, which aligns transmit pins on one device to receive pins on the other. This wiring scheme is ideal for connecting devices with different roles, such as a switch and a router, where one device transmits on pins 1 and 2 and the other receives on those pins. This ensures proper data flow without signal collisions or miswiring. The decision to use a straight-through cable for switch-to-router connections is based on the complementary nature of their Ethernet interfaces. Switch ports are typically configured as MDI (Medium Dependent Interface), while router ports are MDI-X (Medium Dependent Interface Crossover). This difference means a straight-through cable correctly aligns transmit and receive pairs. However, modern Cisco devices support auto-MDIX, which automatically detects cable type and adjusts the interface accordingly, allowing either straight-through or crossover cables to work without manual intervention. A common exam trap is assuming that a crossover cable is required for switch-to-router connections, which was true before auto-MDIX became widespread. Candidates may also confuse rollover cables, which are used for console access, or serial DCE cables, which apply only to serial WAN links. Understanding the physical layer roles and the evolution of auto-MDIX technology helps avoid these mistakes. In practical networking, using straight-through cables simplifies inventory and deployment, while auto-MDIX enhances flexibility and reduces cabling errors.
KKey Concepts to Remember
- A straight-through Ethernet cable connects devices with different interface types, such as a switch and a router, by matching transmit pins to receive pins.
- Auto-MDIX technology automatically detects and corrects for crossover or straight-through cable wiring, allowing modern devices to use straight-through cables regardless of device type.
- Rollover cables are designed for console port connections and do not support standard Ethernet data transmission between switches and routers.
- Serial DCE cables are used for serial WAN interfaces and are not applicable for Ethernet connections between switches and routers.
- Fiber patch cables provide physical layer connectivity for fiber optic interfaces but are not the default or most common cable type for standard Ethernet switch-to-router connections.
- Switch-to-router Ethernet connections typically use straight-through cables because the switch port and router port have complementary pinouts, which is the expected standard in CCNA scenarios.
- Auto-MDIX reduces the need for crossover cables by automatically adjusting the interface pinouts, simplifying network cabling requirements in modern Cisco devices.
- Understanding cable types and their appropriate use cases is essential for configuring physical connectivity in Cisco networks and avoiding common cabling mistakes.
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 straight-through Ethernet cable connects devices with different interface types, such as a switch and a router, by matching transmit pins to receive pins.
What is the correct answer to this question?
The correct answer is: Straight-through Ethernet cable — A straight-through Ethernet cable is the common expected answer for switch-to-router Ethernet connections. On modern interfaces, auto-MDIX often makes crossover requirements less important in practice.
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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