To determine the correct JSON snippet for configuring a new interface according to the YANG model, we need to carefully examine both the YANG model definitions and the provided JSON snippets. Here's a step-by-step explanation:
* YANG Model Analysis:
* The ietf-interfaces YANG module defines a container interfaces with a list interface.
* Each interface has the following important leaves: name, enabled, and description.
* The ietf-ip YANG module augments the interface list with a container ipv4, which includes a list address. Each address has the ip and netmask leaves.
* Key Elements in JSON:
* To configure an interface, the JSON must include the name of the interface, its enabled status, and the IP address configuration.
* The structure should reflect the hierarchy defined by the YANG models.
* Options Analysis:
* Option A:
json
Copy code
"ietf-interfaces:interface": {
"name": "Loopback100",
"enabled": true,
"ietf-ip:ipv4": {
"address": [
{
"ip": "10.255.254.1",
"netmask": "255.255.255.0"
}
]
}
}
* This option correctly follows the hierarchy specified in the YANG model. The interface includes name and enabled leaves and augments with ietf-ip:ipv4 which includes the address list with ip and netmask.
* Option B:
"ietf-interfaces": {
"interface": {
"name": "Loopback100",
"enabled": true,
"ietf-ip": {
"ipv4": {
"address": [
{
"ip": "10.255.254.1",
"netmask": "255.255.255.0"
}
]
}
}
}
}
* This option incorrectly nests interface directly under ietf-interfaces, which does not match the YANG model's structure.
* Option C:
"interface": {
"name": "Loopback100",
"enabled": true,
"ipv4": {
"address": [
{
"ip": "10.255.254.1",
"netmask": "255.255.255.0"
}
]
}
}
* This option misses the namespace prefixes ietf-interfaces and ietf-ip required by the YANG model.
* Option D:
"ietf-interfaces:interface": {
"name": "Loopback100",
"enabled": true,
"ietf-ip:ipv4:address": [
{
"ip": "10.255.254.1",
"netmask": "255.255.255.0"
}
]
}
* This option incorrectly uses ietf-ip:ipv4:address directly, which does not align with the proper hierarchy where address should be nested inside ipv4.
Correct Explanation:
* Option A correctly adheres to the YANG model hierarchy and namespace specifications.
* It properly nests address within ipv4, which is itself nested within ietf-ip augmentation to interface.
* This structure is consistent with how the YANG models define the relationships between the elements.
References:
* Understanding of YANG models and their use: Cisco DevNet YANG Introduction
* YANG Data Models in NETCONF: RFC 6020