The valid get-config reply must show OSPF process ID 400 with network 192.168.128.128/25 enabled for Area 0. A /25 prefix has a block size of 128 addresses, so 192.168.128.128/25 is a valid network boundary and covers addresses from 192.168.128.128 through 192.168.128.255. Any reply that shows the wrong OSPF process, an incorrect network boundary, the wrong prefix length or wildcard equivalent, or a nonzero area does not verify the requested model set. In Cisco IOS XE model-driven configuration, the readback has to match the schema path and values used by the model, not simply produce an approximate CLI interpretation.
Option B is the reply that confirms the intended OSPF object. This verification method is important because YANG automation can fail silently in operational workflows when the payload is syntactically valid but targets the wrong container or key. A get-config verification step confirms the running datastore contains the exact OSPF process and area membership required by the design. Reference topics: YANG OSPF configuration, NETCONF get-config, prefix validation, IOS XE native models.

Cisco SD-WAN uses the vSmart controller as the control-plane component that distributes the information needed for secure data-plane tunnel establishment. Before WAN Edge devices build full-mesh IPsec tunnels, they must learn reachability and security information through the SD-WAN control plane. Cisco documentation describes the vSmart controller as the centralized control-plane element that exchanges OMP routes, policy, TLOC information, and security parameters with WAN Edge routers. In the traditional SD- WAN key-exchange model, vSmart sends IPsec encryption keys to edge devices so the data plane can be secured without each edge independently negotiating IKEv2 with every other edge. vManage is the management platform and is not the key exchange point. vBond performs orchestration, authentication assistance, and NAT traversal during onboarding, but it is not the data-plane key server. IKEv2 may be used in specific newer or configured security models, but the typical Cisco SD-WAN overlay relies on vSmart for scalable key distribution. Reference topics: Cisco SD-WAN control plane, vSmart, OMP, IPsec key distribution, WAN Edge security.

A /26 subnet provides 64 IP addresses, allowing for 62 usable host addresses, which meets the requirement of at least 25 hosts per department. Using 192.168.64.0/26 supports private addressing and allows multiple subnets to be allocated efficiently within the /24 network.