Question 1mediummultiple choice
Full question →mediummultiple choiceObjective-mapped
Which statement best describes a southbound API in a controller-based architecture at a conceptual level?
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
It is associated with communication between the controller and the devices or infrastructure it manages.
This is correct because southbound direction points from controller toward managed infrastructure.
B
Distractor review
It is the client-visible WLAN name.
This is wrong because that describes the SSID.
C
Distractor review
It is the same thing as a default route.
This is wrong because APIs and routing entries are different concepts.
D
Distractor review
It is used only to generate IPv6 addresses with EUI-64.
This is wrong because southbound APIs are not an IPv6 addressing method.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A frequent exam trap is mistaking the southbound API for unrelated networking terms such as SSID, default routes, or IPv6 address generation methods. For example, option B incorrectly associates it with WLAN names (SSIDs), which are unrelated to controller-device communication. Option C confuses APIs with routing concepts like default routes, and option D incorrectly links southbound APIs to IPv6 EUI-64 address generation. These distractors exploit the candidate’s familiarity with common Cisco terms but do not relate to the directional communication role of southbound APIs in controller-based architectures.
Technical deep dive
How to think about this question
In a controller-based network architecture, the southbound API is the interface that allows the network controller to communicate directly with the underlying network devices such as switches, routers, and access points. This communication enables the controller to configure, manage, and monitor the network infrastructure dynamically. The southbound API translates high-level network policies into device-specific commands, facilitating centralized control over distributed hardware. The decision to use a southbound API is based on the need for the controller to push instructions downward to the network devices it manages. This contrasts with northbound APIs, which allow external applications to interact with the controller itself. Southbound APIs typically use protocols like OpenFlow, NETCONF, or RESTCONF in Cisco environments, enabling programmability and automation of device configurations and state retrieval. A common exam trap is confusing the southbound API with unrelated networking concepts such as SSIDs, routing entries, or IPv6 address generation. Understanding that southbound APIs specifically refer to controller-to-device communication helps avoid this mistake. Practically, southbound APIs enable network administrators to automate device management, reducing manual configuration errors and improving network agility.
KKey Concepts to Remember
- A southbound API enables the network controller to communicate and manage the underlying network devices directly.
- Southbound APIs translate high-level network policies into device-specific commands for switches, routers, and access points.
- The controller uses southbound APIs to push configurations and retrieve operational data from managed infrastructure.
- Northbound APIs differ by allowing external applications to interact with the network controller, not the devices.
- Common southbound protocols in Cisco networks include OpenFlow, NETCONF, and RESTCONF for device programmability.
- Southbound APIs are essential for network automation and programmability by centralizing device management.
- Confusing southbound APIs with unrelated concepts like SSIDs, routing entries, or IPv6 address generation is a frequent exam trap.
- Understanding the directional flow of communication helps distinguish southbound APIs as controller-to-device interfaces.
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.
Related practice questions
Related 200-301 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
CCNA subnetting practice questions
Practise IPv4 subnetting, CIDR, masks, host ranges and subnet selection.
CCNA OSPF practice questions
Practise OSPF neighbours, router IDs, metrics, areas and routing-table interpretation.
CCNA VLAN practice questions
Practise VLANs, access ports, trunks, allowed VLANs and switching scenarios.
CCNA STP practice questions
Practise spanning tree, root bridge election, port roles and STP troubleshooting.
CCNA EtherChannel practice questions
Practise LACP, PAgP, port-channel behaviour and bundle requirements.
CCNA ACL practice questions
Practise standard and extended ACLs, permit/deny logic and traffic filtering.
CCNA NAT practice questions
Practise static NAT, dynamic NAT, PAT and inside/outside address translation.
CCNA DHCP practice questions
Practise DHCP scopes, relay, leases and troubleshooting.
CCNA show ip route practice questions
Practise routing-table output, longest-prefix match, AD and route selection.
CCNA show interfaces trunk practice questions
Practise trunk verification and VLAN forwarding across switches.
CCNA wireless security practice questions
Practise WLAN security, authentication and wireless architecture concepts.
CCNA IPv6 practice questions
Practise IPv6 addressing, routes, neighbour discovery and common IPv6 exam traps.
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 southbound API enables the network controller to communicate and manage the underlying network devices directly.
What is the correct answer to this question?
The correct answer is: It is associated with communication between the controller and the devices or infrastructure it manages. — At a conceptual level, a southbound API is associated with communication between the controller and the network infrastructure it manages. In practical terms, if northbound APIs are how applications talk to the controller, southbound APIs describe how the controller interacts downward with devices or the forwarding infrastructure. The CCNA emphasis here is basic directional understanding, not deep vendor-specific protocol detail.
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.
Discussion
Loading comments…
Sign in to join the discussion.