OSPFv2 neighbors do not form just because two routers can ping each other. Several parameters must agree before adjacency can progress. The interfaces must be in the same IP subnet and OSPF area. Hello and dead intervals must match. Authentication, if configured, must match. Stub-area flags must match, and MTU mismatches can prevent database exchange from completing. Router IDs must be unique, but they do not have to match. OSPF process IDs are locally significant on Cisco IOS, so the process number can differ between neighbors. Network type also matters because it affects DR/BDR election and adjacency behavior. Cisco CCNA v1.1 IP Connectivity includes single-area OSPFv2 configuration and neighbor adjacency requirements. The point of the drag-and-drop is to separate mandatory matching values from values that are local-only or simply need uniqueness. A clean OSPF adjacency requires matching operational parameters on the shared link, not identical router configuration everywhere.

The root bridge election is based on the lowest bridge ID. The bridge ID includes priority and MAC address, with priority compared first. If priority values are not provided or are equal, the lowest MAC address becomes the tie-breaker. In the HQ LAN exhibit, Switch 3 has the lowest bridge ID value after the election criteria are applied, so Switch 3 becomes the root bridge. Cisco CCNA 200-301 v1.1 Network Access tests this because STP root placement determines which switch becomes the logical center of the Layer 2 topology. Once the root is selected, all nonroot switches calculate their root ports and designated ports based on path cost and tie-breakers. The physical drawing position of a switch is irrelevant. The root is chosen by numerical bridge ID comparison. The correct answer is C.

Use B for this item. A DHCP helper address is configured on the Layer 3 interface that receives the client broadcast. The first-hop router closest to the client converts DHCP broadcast traffic into unicast traffic toward the DHCP server. In Cisco CCNA 200-301 v1.1, IP Services questions frequently test the practical boundary between similar features: what the feature does, where it is configured, and what problem it is meant to solve. Putting the command near the server, on every router, or on a switch trunk does not intercept the original client DHCPDISCOVER broadcast correctly. A clean way to validate the answer is to map the wording of the scenario to the actual device function. If the feature supplies addressing, forwarding, authentication, trunking, route selection, or controller communication, the answer must match that function exactly rather than a nearby protocol name.

The drag-and-drop mapping is based on each tool’s normal configuration-management model. Ansible is agentless, built around playbooks, and commonly uses SSH over TCP port 22 to communicate with managed nodes. Puppet uses a declarative model and stores configuration logic in manifests, typically written with Puppet’s Ruby-influenced language and saved as .pp files. Chef uses recipes and cookbooks and is associated with a client/server automation model; Chef Push Jobs also uses a command channel for remote execution. The important CCNA 200-301 v1.1 Automation and Programmability lesson is not to memorize marketing language but to separate the operating models: Ansible focuses on simple agentless execution, Puppet emphasizes declarative manifests, and Chef organizes configuration into recipes and cookbooks. The existing mapping follows those technology roles. Reference: Cisco CCNA automation objectives covering configuration management tools and common network automation characteristics.

A DHCP client is a host configured to request IP addressing information automatically. It sends DHCP messages to obtain an address lease and related options such as subnet mask, default gateway, DNS server, and lease duration. The server is the device that owns the address pool and assigns addresses. A workstation that requests a domain name for an IP address is using DNS behavior, not DHCP client behavior. A router can relay DHCP messages or host DHCP pools, but it is not described as a DHCP client unless its own interface is configured to obtain an address dynamically. Cisco CCNA 200-301 v1.1 IP Services expects candidates to separate DHCP client, DHCP server, and DHCP relay functions. In the DHCP exchange, the client initiates discovery because it needs configuration. Therefore, the correct definition is a host that is configured to request an IP address automatically.

172.28.0.0/16 is the only private IPv4 network in the list. RFC 1918 reserves three private address blocks for internal use: 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16. The 172.16.0.0/12 block covers 172.16.0.0 through 172.31.255.255, so 172.28.0.0/16 falls cleanly inside the private range. Private addresses are not globally routed on the public Internet and are commonly used for internal LANs, labs, branch networks, and enterprise addressing plans. The other listed choices are either invalidly written or outside the RFC 1918 private ranges. In real networks, private addressing is normally paired with NAT or routed only inside the organization. CCNA 200-301 v1.1 Network Fundamentals requires candidates to identify private IPv4 ranges and understand why they allow internal communication without Internet-routable addressing. Reference: Cisco CCNA IPv4 addressing fundamentals and RFC 1918 private address allocation.

When configuring VLAN trunking between a Cisco switch and a third-party switch, use IEEE 802.1Q. It is the open standard for VLAN tagging on Ethernet trunks. Cisco ISL was Cisco-proprietary and is obsolete on modern platforms. IEEE 802.1p relates to Class of Service marking inside the Ethernet header, not trunk encapsulation for interswitch VLAN transport. DSCP is an IP-layer QoS marking, not a Layer 2 VLAN trunking method. Cisco CCNA 200-301 v1.1 Network Access expects candidates to know that 802.1Q inserts a VLAN tag so multiple VLANs can traverse one physical trunk link. The native VLAN is carried untagged by default, while other VLANs are tagged. In multivendor networks, standards-based encapsulation is mandatory. Therefore, the action is to configure IEEE 802.1Q. The correct answer is B.