JNCIS-MistAI-Wired flashcards

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

Mist switch management path

Mist-managed EX/QFX switches reach the Mist cloud over outbound HTTPS on TCP 443. No on-premises controller is required; loss of that path makes the switch appear offline while it keeps forwarding traffic.

Port profile

A named, reusable set of port settings such as mode, VLANs, PoE, STP, and storm control. It is assigned to one or many switch ports and can be shared across switches.

Access versus trunk port

An access port carries a single untagged VLAN for an end device. A trunk port carries multiple tagged VLANs and may also carry one untagged native VLAN toward another switch.

Config precedence in Mist

The effective switch configuration merges org template, site template, and device override. The most specific level wins, so a device override beats the site template for the same setting.

PoE budget overrun

Each switch has a total PoE power budget. When attached devices request more than the budget, later ports are denied power rather than the configuration failing, and the event is logged.

LACP versus static LAG

A LAG bundles physical ports into one logical link. LACP negotiates membership and detects misconfiguration; a static LAG does not negotiate, so both ends must be configured identically.

LLDP role in assurance

LLDP and LLDP-MED advertise neighbor identity and capabilities. Mist uses these neighbors to build wired topology and identify attached APs and phones, so disabling LLDP reduces topology accuracy.

RSTP default on EX

Juniper EX switches default to Rapid Spanning Tree Protocol. Mist exposes edge, BPDU blocking, and loop protection per port profile to protect access ports from loops.

Switch onboarding sequence

Create org and site, claim the switch by code or inventory assignment, apply a switch template, then verify it comes online. DNS, NTP, and outbound 443 must work first.

Switch template scope

A template is a configuration container assigned to a switch model or specific switches at org or site scope. Device-level overrides handle exceptions instead of duplicating templates per switch.

Site and switch variables

Variables substitute site-specific values such as VLAN IDs, subnets, or uplink port names into a shared template at apply time. One template can then serve many sites without hard-coding.

Claim code versus serial

A switch is onboarded by claim code or by assigning its serial in inventory. The claim is tied to the device serial and must be released from the current org before another org can claim it.

Config diff before push

Mist stages configuration changes and shows a diff between running and intended config before applying. A failed push leaves the switch on its prior config and records an event.

Firmware upgrade scheduling

Firmware upgrades are scheduled per switch or site from the Mist UI. The switch reloads during upgrade, so schedule a maintenance window and confirm flash space and connectivity first.

Disabled port profile

A hardening pattern that assigns a profile with the port administratively down to all unused switch ports, preventing unauthorized devices from connecting to spare access ports.

Role-based port profile naming

Design one port profile per role, such as AP uplink, user access, core trunk, server, and unused. Role-based naming keeps templates readable and prevents misassignment across switches.

Static IP prerequisites

Before a switch can stay connected to Mist, it needs valid DNS resolution, accurate NTP time, and a working route to the internet on TCP 443. Failures here cause repeated offline states.

Site-level VLAN object

Mist defines VLANs at site scope with an ID and name. Port profiles then reference those VLAN objects for access or trunk membership rather than typing raw IDs per port.

Wired SLE

A Service Level Expectation scores wired performance from 0 to 100 using classified events. Switch health and client connectivity SLEs let you drill from a poor score to the specific classifier.

SLE classifier

A classifier is the tagged reason an SLE event missed, such as DHCP failure, authentication failure, or port down. Troubleshooting starts from the classifier, not the aggregate score.

Marvis Actions

A prioritized list of detected problems with suggested remediation, such as high switch CPU, port flapping, or PoE overrun. Each action links to the affected switch and evidence.

Offline but forwarding

A switch that passes traffic locally but shows offline in Mist has a management-path fault: check outbound HTTPS, DNS, NTP skew, and whether a recent config push or upgrade failed.

Port flapping diagnosis

Repeated link up/down events on one port indicate a cabling, optic, or duplex mismatch. Flapping ports commonly cause client connectivity SLE misses and appear as repeated link events.

PoE denial event

When a powered device requests more than its class allows or the switch budget is exhausted, PoE is denied and logged. Compare requested class with delivered power on the port.

Layer 2 loop indicators

Broadcast storms and MAC address flapping across ports signal a Layer 2 loop. Check STP state and whether edge or loop protection is enabled on the affected access ports.

Client path troubleshooting

Locate the client in Mist, then check its switch port, VLAN, 802.1X or MAC authentication result, and DHCP lease. An IP with no connectivity usually points to VLAN or upstream routing.

Interface error counters

CRC, alignment, and drop counters on a switch port reveal physical-layer problems. Rising error counters with normal link state indicate bad cabling, dirty optics, or a duplex mismatch.

Switch health SLE inputs

Switch health draws on CPU, memory, PoE usage, port status, and firmware state. A declining score points to a resource or port condition rather than to a client-specific fault.

Mist API token

A token created in org settings and sent as an Authorization: Token header. It is scoped to the org or specific sites with read or write rights and should be rotated regularly.

API resource paths

Mist REST paths follow /api/v1/orgs/{org_id}/ and /api/v1/sites/{site_id}/ patterns. Switches, templates, port profiles, sites, and stats are separate collections read and modified individually.

Read-modify-write with PUT

A PUT replaces the target object rather than merging it. Automation must GET the current object, modify the needed fields, then PUT the whole object back to avoid erasing settings.

Mist webhooks

Webhooks push event JSON to an external endpoint when subscribed topics fire, such as device events or alarms. They replace polling and feed ticketing or monitoring systems in near real time.