DevNet Professional flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

YANG

A data modeling language that defines the structure, syntax, and semantics of configuration and state data for network devices, consumed by NETCONF, RESTCONF, and gNMI.

NETCONF transport

NETCONF uses SSH as its transport on TCP port 830 by default and encodes protocol messages and data in XML, with operations such as get-config and edit-config.

RESTCONF

A RESTful protocol that exposes YANG-modeled data over HTTPS using HTTP verbs and paths beginning with /restconf/data, supporting both JSON and XML encodings.

gNMI

gRPC Network Management Interface: a protobuf-based protocol for get, set, subscribe, and capability RPCs, widely used for model-driven streaming telemetry and configuration.

Idempotency

The property that running an operation multiple times produces the same end state as running it once, with no duplicate or cumulative side effects.

Declarative automation

An approach where the operator specifies the desired end state and the tool computes the steps to reach it, reconciling differences between intended and actual state.

YANG list node

A repeatable YANG node containing multiple entries, each uniquely identified by one or more key leaves, similar to a table with rows.

Streaming telemetry

A push-based monitoring model where devices send periodic or on-change data updates to a collector, replacing polling-based SNMP collection.

DNA Center token auth

Authenticate by POSTing credentials to /dna/system/api/v1/auth/token; the response contains a token sent as the X-Auth-Token header on subsequent Intent API calls.

Meraki API key header

Meraki Dashboard API requests include the header X-Cisco-Meraki-API-Key with a generated key, and use the base URL https://api.meraki.com/api/v1.

vManage authentication

Cisco SD-WAN vManage REST API authenticates by POSTing credentials to /j_security_check, which returns a JSESSIONID cookie used for later /dataservice calls.

APIC aaaLogin

Cisco ACI APIC authentication endpoint that accepts credentials and returns a token, typically stored in the APIC-Cookie cookie, for subsequent REST calls.

IOS XE RESTCONF enablement

On IOS XE, RESTCONF requires ip http secure-server plus restconf in global configuration; model data is then reachable under /restconf/data/ paths.

Intersight signed requests

Cisco Intersight API calls are signed with an API key ID and secret using HMAC, rather than a bearer token, to authenticate each HTTP request.

HTTP 429 handling

Status 429 means rate limited; clients should read the Retry-After header and back off before retrying rather than immediately resending the request.

API pagination

List endpoints return results in pages using parameters such as offset/limit or startingAfter/perPage; clients loop until an empty page is returned.

Git commit

A local snapshot of staged changes with a unique hash, author, timestamp, and message, forming a node in the repository history graph.

Pull request

A review gate where a branch's changes are proposed for merge into a target branch, enabling code review, automated checks, and approval before integration.

CI pipeline

An automated workflow triggered by code changes that lints, tests, and builds artifacts, failing when any step returns a non-zero exit code.

Jinja2 template

A text templating engine using {{ variable }} for substitution, {% for %} and {% if %} for control flow, and filters such as | default to render device configurations.

Ansible playbook

A YAML file defining ordered plays and tasks that apply idempotent modules to inventory hosts, commonly used to push configuration and gather facts.

Terraform plan

A dry-run that compares desired configuration with recorded state and shows the proposed create, update, and destroy actions before apply executes them.

Unit test mocking

Replacing real device or API calls with simulated responses, using libraries such as unittest.mock or responses, so tests run fast without network dependencies.

Pipeline as code

Defining CI/CD stages in version-controlled files such as Jenkinsfile, .gitlab-ci.yml, or GitHub Actions YAML, so the pipeline itself is reviewed and versioned.

Source of truth

The authoritative system, such as NetBox or NSO, that holds intended network state and from which automation reads data to reconcile device configurations.

Configuration drift

The divergence between a device's actual running configuration and the intended state stored in the source of truth, detected by periodic comparison.

Cisco NSO service

A service package that maps a high-level service model to per-device configuration through NEDs, applied as a transaction with rollback support.

Confirmed commit

A NETCONF commit option that applies changes provisionally and automatically reverts them unless a confirming commit arrives within a timeout.

Golden configuration

A reference configuration baseline used in compliance checks; automation diffs device configs against it and flags deviations for remediation.

Exponential backoff

A retry strategy where wait time doubles between attempts, used for transient errors such as HTTP 5xx or 429, while 4xx client errors fail fast.

NetBox API

A REST API under /api/ using token authentication via the Authorization: Token header, exposing objects such as dcim/devices and ipam/ip-addresses.

Concurrency limits

Caps on simultaneous device or API operations, implemented with thread pools or asyncio semaphores, preventing overload when automating large inventories.