JNCIS-MistAI-Wireless cheat sheet

802.11 channels: 2.4 GHz uses 1-14 (1/6/11 non-overlapping); 5 GHz uses 36-165 with 20 MHz channel width; 6 GHz (Wi-Fi 6E) uses 1-233 with up to 160 MHz.

Modulation scales with SNR: 802.11ax MCS 0-11; higher MCS (1024-QAM) needs stronger signal; lower MCS extends range.

RSSI thresholds: -65 dBm or better for voice, -67 to -70 dBm for data, below -75 dBm likely to cause retries.

SNR = RSSI - noise floor; 25 dB or higher is good; 802.11ax needs about 20 dB for high MCS.

Bands: 2.4 GHz longer range and more interference; 5 GHz more channels, less interference; 6 GHz cleanest, requires WPA3 and no legacy clients.

Roaming types: 802.11r fast BSS transition (FT), 802.11k neighbor reports, 802.11v BSS transition management; clients decide when to roam.

Security progression: WEP (broken), WPA/TKIP (deprecated), WPA2/AES-CCMP, WPA3/SAE (mandatory on 6 GHz); WPA3-Enterprise uses 192-bit suite.

OFDMA (802.11ax) splits a channel into resource units (RUs) for multi-user uplink/downlink; MU-MIMO uses spatial streams.

Throughput estimate: 20 MHz ~ 100 Mbps PHY; 40 MHz ~ 200 Mbps; 80 MHz ~ 400 Mbps; real-world is roughly half of PHY rate.

Mist architecture is cloud-first: access points connect to Mist cloud over HTTPS/outbound; management and telemetry are cloud-hosted.

Onboarding: APs are claimed by org/site using claim code or MAC; DHCP option 43 or DNS can redirect APs to the correct cloud.

AP modes include: Mist-managed (cloud), standalone, and WAN assurance; APs need outbound access to Mist cloud endpoints (TCP 443).

Site configuration includes RF template, WLAN template, and device profiles; templates are reusable across sites.

WLAN template defines SSIDs, security, VLAN, and band settings; RF template defines channel/power and band steering.

Deployment types: greenfield, overlay, and replacement; site variables and site groups simplify multi-site deployments.

Mist Edge and Mist VPN enable branch connectivity; Juniper Mist supports wired/wireless/WAN assurance under one cloud.

Firmware upgrades are scheduled from the Mist UI; APs can be upgraded per site or per device with maintenance windows.

SSID profiles: open, WPA2-PSK, WPA3-SAE, WPA2/WPA3 transition, 802.1X (RADIUS), and captive portal (external or Mist-hosted).

VLAN tagging: SSIDs can be untagged (native VLAN) or tagged; dynamic VLAN assignment via RADIUS attributes.

Band steering: steers dual-band clients to 5 GHz; can be 'balanced', 'prefer-5GHz', or disabled; use with client capability awareness.

Fast roaming: 802.11r (FT) and OKC; enable only when clients support it; can break legacy clients if misconfigured.

RF template settings: channel width, transmit power, minimum data rate, and band steering; adaptive RF adjusts based on site survey and neighbor APs.

WLAN scheduling: SSIDs can be enabled/disabled by time schedule; guest portals can be time-limited.

Client limits: max clients per AP and per SSID are configurable; rate limiting and QoS can be applied per SSID.

RADIUS/CoA: Mist supports RADIUS accounting and CoA (change of authorization) for dynamic policy and VLAN changes.

Mist SLEs (Service Level Expectations) include: coverage, capacity, roaming, AP uptime, successful connect, time to connect, throughput, and Wi-Fi interference.

SLE classification: each SLE has a classifier with 'good', 'fair', 'poor' thresholds; default thresholds vary by SLE type.

Marvis Actions surface top issues (e.g., bad cable, PoE, DHCP, DNS, coverage) with severity and affected scope.

AP details page shows channel, power, client count, and RF neighbors; site dashboard shows SLE trends over time.

Alarms and events: Mist generates alarms for AP down, bad cable, PoE, and rogue AP; events are searchable in the UI.

Packet capture and live troubleshooting: Mist supports remote packet capture and live client view; no on-prem controller needed.

Webhooks and integrations: Mist can push events/alarms to Slack, Teams, PagerDuty, or custom webhooks via API.

Mist API: REST API allows programmatic access to sites, devices, clients, and SLE metrics; API tokens are scoped per org.

Marvis is Mist's AI-driven virtual network assistant; it answers natural-language queries about network health, clients, and APs.

Marvis Actions are prioritized, actionable issues with root-cause hints (e.g., DHCP failure, DNS failure, coverage hole, bad cable).

Marvis uses SLE data, client events, and telemetry to correlate symptoms; it can explain 'why is this client slow' with evidence.

Marvis queries support scope: org, site, AP, client, or SSID; results include related events and suggested next steps.

Marvis can be accessed via the Mist UI and via API; it is included in Mist cloud; no separate appliance.

Marvis Actions severity levels: critical, warning, info; actions have 'impact' and 'scope' fields.

Marvis can detect misconfigurations (e.g., VLAN mismatch, missing DHCP) and recommend remediation steps.

Marvis is not a replacement for packet capture; it summarizes and correlates but may require manual verification.

Mist LBS uses APs as sensors and client RSSI to estimate location; accuracy depends on AP density and calibration.

Location services include: asset visibility, zone-based analytics, and proximity notifications; requires a subscription (Mist LBS).

Mist supports BLE (Bluetooth Low Energy) for asset tags and wayfinding; APs with BLE radios act as scanners/beacons.

vBLE (virtual BLE) uses AP antennas to emulate BLE beacons; no physical beacon hardware needed.

Location accuracy: typically 3-10 meters with vBLE; improves with more APs and calibration; zone-level accuracy is more reliable than precise coordinates.

Mist LBS APIs expose location data for integrations (e.g., asset tracking, analytics dashboards).

Privacy: LBS can track client devices; orgs should define consent and retention policies; Mist provides data retention settings.

Use cases: asset tracking, wayfinding, proximity marketing, occupancy analytics, and zone-based policy.