Dashboard: Network Health WAN status doesn't reflect a WAN disconnect, doesn't match page banner.

[kateatlinksys]

Reproduce steps:

1. Login to Linksys Now.
2. Unplug the WAN cable.
3. Check the Network Health card.

Actual result:
WAN status is shown as Excellent (Health 100 / Errors 0/s / Loss 0.00%) even though the WAN is disconnected — the page-top banner on the same screen correctly shows "Couldn't establish a connection…". The card and the banner don't match each other.

Expected result:
When the WAN is down, the Network Health card should reflect the disconnect (degraded WAN status / not "Excellent"), consistent with the connection banner.

Env.: M60DU-EU / Pinnacle 2.0 FW 1.2.2.26062820 / Linksys Now 2.5.0.700525

Log:
GUI_networkhealth_wanerror_0716.txt

Screenshot:

[AustinChangLinksys]

🔍 Automated investigation (preliminary triage)

Line: 2.x / USP (TR-369)

Root cause:

• UI defect: The Network Health card computes the WAN health score purely from packet-loss/error stats and never consults the WAN link-up state, so a disconnected WAN with no traffic yields 0% loss → score 100 → "Excellent". The backend correctly reports the WAN as down; the card simply ignores that signal.

Evidence (from attached log.txt):

1. The backend correctly reports the WAN interface as down (isUp=false, empty IP/gateway):

2026-07-16T09:18:51.470 [D][USP][WanData]: Fetched — ip=, isUp=false, gateway=

2. The Network Health card, however, derives its score only from WAN interface traffic stats — with the WAN down there is no traffic, so errors/loss are 0:

"Device.IP.Interface.2.Stats.PacketsSent": "4844162",
"Device.IP.Interface.2.Stats.PacketsReceived": "7121890",
"Device.IP.Interface.2.Stats.ErrorsSent": "0",
"Device.IP.Interface.2.Stats.ErrorsReceived": "0",

(Interface.2 = eth-wan. Counters are static/cumulative; with no live traffic the derived per-second loss is 0.)

3. Code path confirms the score never factors in link state. In lib/page/_shared/models/network_health_helpers.dart, the health score is computed from loss alone:

static int computeHealthScore(InterfaceTrafficSnapshot wan) {
  final lossPercent = computeLossPercent(wan);
  return _scoreFromLoss(lossPercent);
}
static int _scoreFromLoss(double lossPercent) {
  if (lossPercent <= 0) return 100;  // 0 loss -> 100 -> "Excellent"
  ...
}

And in lib/page/dashboard/views/components/usp_network_health_card.dart, the WAN tile derives its tier solely from that score, with no isUp check:

final wan = state.latest?.interfaces[TrafficInterface.wan];
final wanScore = wan != null ? NetworkHealthHelpers.computeHealthScore(wan) : 100;
final wanTier = NetworkHealthHelpers.tierFromScore(wanScore);

InterfaceTrafficSnapshot (lib/page/_shared/models/traffic_analysis_state.dart) carries only byte/packet/error/discard counters — it has no link-up field — so the card structurally cannot reflect a disconnect. The page-top banner uses the WanData isUp signal directly, which is why the banner correctly shows "Couldn't establish a connection…" while the card still says "Excellent".

Confidence: High — root cause located in code (score depends only on packet loss, WAN link state never consulted) and corroborated by the attached UI log showing isUp=false alongside 0-error/0-loss WAN counters. This is a single-layer UI defect; no backend error is involved (the backend reports the disconnect correctly).

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Auto-generated triage by Austin's tooling, pending Austin's review. Not a fix commitment.