diff --git a/SCHEMAS.md b/SCHEMAS.md
index 7ec89fe..e535687 100644
--- a/SCHEMAS.md
+++ b/SCHEMAS.md
@@ -47,7 +47,9 @@ Node advertisements announcing presence and metadata.
   "adv_type": "string (optional)",
   "flags": "integer (optional)",
   "lat": "number (optional)",
-  "lon": "number (optional)"
+  "lon": "number (optional)",
+  "route_type": "string (optional)",
+  "advert_timestamp": "integer (optional)"
 }
 ```
 
@@ -58,6 +60,8 @@ Node advertisements announcing presence and metadata.
 - `flags`: Node capability/status flags (bitmask)
 - `lat`: GPS latitude when provided by decoder metadata
 - `lon`: GPS longitude when provided by decoder metadata
+- `route_type`: Route type of the advertisement packet — `"flood"` (original flood), `"transport_flood"` (relayed flood), `"direct"` (zero-hop local), `"transport_direct"` (relayed direct). Only present for LetsMesh-decoded adverts; native mode adverts have `route_type=NULL`.
+- `advert_timestamp`: Node's own Unix timestamp (uint32) from the decoded advert payload. Used for deduplication when within ±4 hours of `received_at`. May be `NULL` for native mode adverts or when the decoder does not provide a timestamp.
 
 **Example**:
 ```json
@@ -67,7 +71,9 @@ Node advertisements announcing presence and metadata.
   "adv_type": "repeater",
   "flags": 218,
   "lat": 42.470001,
-  "lon": -71.330001
+  "lon": -71.330001,
+  "route_type": "flood",
+  "advert_timestamp": 1747300000
 }
 ```
 
diff --git a/alembic/versions/20260515_1920_add_route_type_advert_timestamp.py b/alembic/versions/20260515_1920_add_route_type_advert_timestamp.py
new file mode 100644
index 0000000..284adf7
--- /dev/null
+++ b/alembic/versions/20260515_1920_add_route_type_advert_timestamp.py
@@ -0,0 +1,33 @@
+"""add route_type and advert_timestamp to advertisements
+
+Revision ID: 20260515_1920
+Revises: 20260503_1800
+Create Date: 2026-05-15 19:20:00.000000
+
+"""
+
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+from alembic import op
+
+revision: str = "20260515_1920"
+down_revision: Union[str, None] = "20260503_1800"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.add_column(
+        "advertisements",
+        sa.Column("route_type", sa.String(20), nullable=True),
+    )
+    op.add_column(
+        "advertisements",
+        sa.Column("advert_timestamp", sa.DateTime(timezone=True), nullable=True),
+    )
+
+
+def downgrade() -> None:
+    op.drop_column("advertisements", "advert_timestamp")
+    op.drop_column("advertisements", "route_type")
diff --git a/docs/i18n.md b/docs/i18n.md
index aed0f85..e13d7c3 100644
--- a/docs/i18n.md
+++ b/docs/i18n.md
@@ -297,7 +297,18 @@ Mobile sort dropdown labels for the nodes list page:
 
 ### 10. `advertisements`
 
-Sort options for the advertisements list page:
+Route type filter and sort options for the advertisements list page:
+
+#### Route Type Filter
+
+| Key | English | Context |
+|-----|---------|---------|
+| `filter_route_type_label` | Advert Type | Label for route type filter dropdown |
+| `route_type_all` | All | Show all route types (no filter) |
+| `route_type_flood` | Flood & Relay | Show flood and transport_flood adverts (default) |
+| `route_type_direct` | Zero-hop only | Show only direct (zero-hop) adverts |
+| `route_type_unknown` | Unknown | Displayed when route_type is NULL (historical records) |
+| `col_route_type` | Type | Table column header for route type |
 
 #### Sort Options (`advertisements.sort`)
 
diff --git a/docs/plans/20260515-1920-advertisement-frequency/plan.md b/docs/plans/20260515-1920-advertisement-frequency/plan.md
new file mode 100644
index 0000000..2d1eb10
--- /dev/null
+++ b/docs/plans/20260515-1920-advertisement-frequency/plan.md
@@ -0,0 +1,267 @@
+# Advertisement Frequency Investigation
+
+**Date**: 2026-05-15
+**Status**: Decisions made, ready for implementation
+
+## Problem Statement
+
+Advertisements appear too frequently on the advertisements page. MeshCore nodes are expected to advertise at 6+ hour intervals (repeaters default to 12-hour flood adverts), yet the hub shows advertisements as frequently as every 3 hours for some nodes.
+
+## Research Findings
+
+### How the Collector Identifies Advertisements
+
+The collector identifies advertisements through a precise chain:
+
+1. **MQTT subscription**: `{prefix}/+/+/packets` (only the `packets` feed type is processed for advertisements)
+2. **Decoding**: The `meshcoredecoder` library decodes the raw packet hex and extracts the header, including **payload type** and **route type**
+3. **Normalization**: `LetsMeshNormalizer._build_letsmesh_advertisement_payload()` maps **decoded payload type `4` (PAYLOAD_TYPE_ADVERT)** to the `advertisement` event type
+4. **Persistence**: `handle_advertisement()` creates an `Advertisement` database record
+
+The `status` and `internal` feed types are explicitly excluded from advertisement processing (they become `letsmesh_status` and `letsmesh_internal` event logs).
+
+### Decoded Advert Payload Structure (Type 4)
+
+The `meshcoredecoder` library decodes advert packets (type 4) into:
+
+| Field | Type | Description |
+|-------|------|-------------|
+| `publicKey` | string (64 hex) | Ed25519 public key of advertising node |
+| `timestamp` | uint32 | **Node's internal Unix timestamp** when the advert was generated |
+| `signature` | string (128 hex) | Ed25519 signature |
+| `appData.flags` | uint8 | Flags byte: bits 0-3 = device role, bit 4 = hasLocation, bit 5 = hasFeature1, bit 6 = hasFeature2, bit 7 = hasName |
+| `appData.deviceRole` | int | 1=Chat, 2=Repeater, 3=RoomServer, 4=Sensor |
+| `appData.location` | object | `{latitude, longitude}` if hasLocation flag set |
+| `appData.batteryVoltage` | float | Battery voltage in V (if HasFeature1 flag) |
+| `appData.name` | string | Node name (if hasName flag set) |
+
+### Packet Header Route Types
+
+The decoded packet header includes a `routeType` field that the normalizer currently **ignores**:
+
+| Route Type | Value | Description |
+|-----------|-------|-------------|
+| `TransportFlood` | 0 | Repeater-forwarded flood advertisement |
+| `Flood` | 1 | Original flood advertisement from source node |
+| `Direct` | 2 | Direct/zero-hop advertisement (local broadcast) |
+| `TransportDirect` | 3 | Repeater-forwarded direct message |
+
+### Root Cause: Zero-Hop + Flood Adverts
+
+MeshCore has **two distinct advertisement mechanisms** ([source: MeshCore FAQ](https://github.com/meshcore-dev/MeshCore/blob/main/docs/faq.md)):
+
+| Advert Type | CLI Command | Default Interval | Route Type | Behavior |
+|-------------|-------------|-----------------|------------|----------|
+| **Zero-hop (local)** | `set advert.interval {minutes}` | Varies by device | `Direct` (0x02) | Broadcast to nearby nodes only, not forwarded |
+| **Flood** | `set flood.advert.interval {hours}` | 12 hours (repeaters) | `Flood` (0x01) → forwarded as `TransportFlood` (0x00) | Broadcast and repeated by all repeaters |
+
+**Both types have payload type 4.** The current normalizer does not differentiate between them.
+
+#### Frequency Analysis
+
+For a node with typical settings:
+- Zero-hop interval: 240 minutes (4 hours) — common for companion nodes with auto-advert enabled
+- Flood interval: 12 hours (default for repeaters)
+
+The observer captures both over the air, creating advertisement records at the **combined** rate. With both active, the observed interval is approximately every 3-4 hours, explaining the reported behavior.
+
+Additionally, **flood adverts are forwarded by repeaters** as `TransportFlood`. If the same flood arrives via different paths >120 seconds apart (unlikely for local mesh but possible for large networks), duplicate records are created.
+
+### Current Deduplication
+
+Advertisements are deduplicated using `compute_advertisement_hash()`:
+
+```
+MD5(public_key | name | adv_type | flags | time_bucket)
+```
+
+Where `time_bucket` rounds `received_at` down to the nearest **120-second** window.
+
+- **Same content + same node within 2 minutes**: Deduplicated (same hash)
+- **Same content + same node after 2 minutes**: New record (different bucket)
+- **Different content (e.g., name change)**: New record regardless of timing
+- **Multi-observer**: When deduplicated, additional observers are recorded in the `event_observers` junction table with per-observer SNR/path_len
+
+### Available But Unused Data
+
+The decoded advert payload includes a `timestamp` field — the **node's own Unix timestamp** when it generated the advert. This field is:
+- Decoded by `meshcoredecoder` and available in `decoded_payload.timestamp`
+- **Not extracted** by the normalizer's `_build_letsmesh_advertisement_payload()`
+- **Not stored** in the `Advertisement` model
+
+This timestamp could be used to:
+- Detect relayed/delayed advertisements (node timestamp << received_at)
+- Compute true advertisement intervals per node
+- Distinguish original adverts from rebroadcasts (same node timestamp, different received_at)
+
+## Decision: Adopt Options A + C + D
+
+All three options are complementary and will be implemented together:
+
+- **Option A** — Store route type on the `Advertisement` model, expose in API/UI, default to showing only flood adverts
+- **Option C** — Use the node's advert `timestamp` for deduplication time bucketing instead of `received_at`, and store it as `advert_timestamp` on the model
+- **Option D** — Increase deduplication bucket from 120s to 300s (5 minutes) for both advertisements and telemetry
+
+Option B (skip zero-hop at ingestion) is rejected — preserving all data is preferable.
+
+### Design Decisions
+
+| Decision | Choice | Rationale |
+|----------|--------|-----------|
+| Include `route_type` in dedup hash? | **No** | Zero-hop and flood adverts from same node have different timestamps; edge case of identical content+timestamp is practically impossible. Simpler hash preferred. |
+| Validate advert_timestamp? | **Yes: ±4h from `received_at`** | Node clocks without GPS may be wrong (0, far future, etc.). If advert_timestamp differs by >4 hours from `received_at`, fall back to `received_at` for dedup bucketing. Raw timestamp is always stored for diagnosis. |
+| Dashboard metrics scope? | **All flood-only** | `total_advertisements`, `advertisements_24h`, `advertisements_7d`, `recent_advertisements`, and `/activity` endpoint all count flood-only (plus NULL for historical records). Consistent with default UI filter. |
+| Telemetry bucket change? | **Yes, also 300s** | Apply consistent 5-minute bucketing to `compute_telemetry_hash()` alongside advertisements. |
+| Route type in UI? | **Separate column** | Add a 5th "Type" column to the table with a route type badge. Mobile cards show badge inline next to node name. |
+
+### Combined Design
+
+#### 1. Normalizer Changes (`letsmesh_normalizer.py`)
+
+Extract two additional fields from the decoded packet in `_build_letsmesh_advertisement_payload()`:
+
+- `route_type` — from the top-level `routeType` field in the decoded packet (values: 0, 1, 2, 3)
+- `advert_timestamp` — from `decoded_payload.timestamp` (uint32 Unix timestamp from the node)
+
+Map route type values to canonical strings:
+
+| routeType | Stored Value | Label |
+|-----------|-------------|-------|
+| 0 | `transport_flood` | Flood (relayed) |
+| 1 | `flood` | Flood (original) |
+| 2 | `direct` | Zero-hop (local) |
+| 3 | `transport_direct` | Direct (relayed) |
+
+Both fields are added to `normalized_payload` and passed through to the handler.
+
+#### 2. Deduplication Changes (`hash_utils.py`)
+
+Update `compute_advertisement_hash()` to:
+
+- Accept an optional `advert_timestamp` parameter (datetime from the node's timestamp)
+- Use `advert_timestamp` for time bucketing when provided, falling back to `received_at`
+- Increase default `bucket_seconds` from 120 to **300** (5 minutes)
+- Fix existing docstring bug: docstring says default is 30, actual is 120 (correct to 300)
+
+Also update `compute_telemetry_hash()` to increase `bucket_seconds` default from 120 to 300 for consistency.
+
+#### 3. Advert Timestamp Validation (`handlers/advertisement.py`)
+
+Before using `advert_timestamp` for dedup bucketing, validate it:
+
+```
+delta = abs(advert_timestamp - received_at_datetime)
+if delta > timedelta(hours=4):
+    advert_timestamp_for_hash = None  # fall back to received_at
+else:
+    advert_timestamp_for_hash = advert_timestamp_datetime
+```
+
+Raw `advert_timestamp` is always stored on the model regardless of validation, so operators can diagnose clock skew.
+
+#### 4. Database Model Changes (`models/advertisement.py`)
+
+Add two new nullable columns to the `Advertisement` model:
+
+- `route_type: Mapped[str | None]` — canonical route type string (`"flood"`, `"transport_flood"`, `"direct"`, `"transport_direct"`)
+- `advert_timestamp: Mapped[datetime | None]` — node's own timestamp from the decoded advert payload (stored as timezone-aware UTC)
+
+Both nullable to maintain backward compatibility with existing records.
+
+#### 5. Handler Changes (`handlers/advertisement.py`)
+
+- Extract `route_type` and `advert_timestamp` from the normalized payload
+- Validate `advert_timestamp` (±4h window vs `received_at`); if invalid, use `received_at` for dedup bucketing, still store raw value
+- Convert valid `advert_timestamp` (uint32 epoch) to `datetime` with `datetime.fromtimestamp(ts, tz=timezone.utc)`
+- Pass validated `advert_timestamp` to `compute_advertisement_hash()` for time bucketing
+- Store `route_type` and `advert_timestamp` on the `Advertisement` record
+
+#### 6. API Changes (`api/routes/advertisements.py`)
+
+Add `route_type` query parameter to `GET /api/v1/advertisements`:
+
+- Accept comma-separated values: e.g. `flood,transport_flood`
+- Default: `flood,transport_flood` — excludes zero-hop (direct) adverts by default
+- SQL: `WHERE route_type IN ('flood', 'transport_flood') OR route_type IS NULL` (NULL included for historical records)
+- Pass empty string to show all route types (no WHERE clause on route_type)
+- `route_type=none` or `route_type=all` as alternate ways to disable filter
+
+Add `route_type` and `advert_timestamp` to the `AdvertisementRead` schema.
+
+Add `route_type` to the single-advert `GET /{advertisement_id}` response schema.
+
+#### 7. Dashboard Changes (`routes/dashboard.py`)
+
+All advertisement metrics in `/stats` switch to flood-only:
+
+| Metric | Change |
+|--------|--------|
+| `total_advertisements` | Count only `route_type IN ('flood', 'transport_flood') OR route_type IS NULL` |
+| `advertisements_24h` | Same filter + `received_at >= 24h ago` |
+| `advertisements_7d` | Same filter + `received_at >= 7d ago` |
+| `recent_advertisements` (last 10) | Same filter |
+
+The `/activity` endpoint also applies the flood-only filter.
+
+`NULL` route types are included in all dashboard counts to avoid hiding historical data.
+
+#### 8. Frontend Changes (`pages/advertisements.js`)
+
+**Route type filter dropdown:**
+- Options: "Flood & Relay" (default, `?route_type=flood,transport_flood`), "All" (no filter), "Zero-hop only" (`?route_type=direct`)
+- Added to the filter card alongside existing search and observer filters
+
+**Route type column:**
+- Add a 5th column "Type" between "Public Key" and "Time" in the table
+- Display as colored badge: `flood`/`transport_flood` (blue), `direct` (green), NULL (gray "Unknown")
+- Mobile cards: badge shown inline next to node name
+
+**i18n keys needed in `en.json`:**
+```
+"advertisements": {
+    "filter_route_type_label": "Advert Type",
+    "route_type_all": "All",
+    "route_type_flood": "Flood & Relay",
+    "route_type_direct": "Zero-hop only",
+    "route_type_unknown": "Unknown",
+    "col_route_type": "Type",
+    ...
+}
+```
+
+#### 9. Existing Data Migration
+
+Existing `Advertisement` records will have `route_type=NULL` and `advert_timestamp=NULL`. All API and dashboard filters that default to flood-only must include `WHERE route_type IS NULL` to avoid hiding historical data. A future cleanup could backfill these from stored `event_hash` patterns or decoded payload logs, but this is not required for initial implementation.
+
+### Deduplication Behavior (After Change)
+
+| Scenario | Before | After |
+|----------|--------|-------|
+| Same node, same content, same flood, 2 observers <2min apart | Deduplicated (1 record, 2 observers) | Deduplicated (1 record, 2 observers) |
+| Same node, same content, same flood, 2 observers 3min apart | **2 records** (different 120s buckets) | Deduplicated (same node timestamp, 5min bucket) |
+| Same node, zero-hop at T, flood at T+4h | 2 records | 2 records (different node timestamps, 4h apart) |
+| Same node, flood original + flood relayed 30s later | Deduplicated | Deduplicated (same node timestamp) |
+| Same node, content changed (name update) | 2 records | 2 records (different hash) |
+| Node with broken clock (timestamp off by 2 days) | N/A (no advert_timestamp) | Uses `received_at` for bucketing (validation rejects timestamp), raw value still stored |
+
+## Affected Files
+
+| File | Change |
+|------|--------|
+| `src/meshcore_hub/common/models/advertisement.py` | Add `route_type` and `advert_timestamp` columns |
+| `src/meshcore_hub/common/hash_utils.py` | Add `advert_timestamp` parameter, increase buckets to 300s (adv + telemetry), fix docstring |
+| `src/meshcore_hub/collector/letsmesh_normalizer.py` | Extract `routeType` and `timestamp` from decoded packet |
+| `src/meshcore_hub/collector/handlers/advertisement.py` | Pass route type + advert timestamp, validate ±4h, use for dedup |
+| `src/meshcore_hub/common/schemas/messages.py` | Add `route_type` and `advert_timestamp` to `AdvertisementRead` |
+| `src/meshcore_hub/api/routes/advertisements.py` | Add `route_type` filter parameter, update base query and single-advert endpoint |
+| `src/meshcore_hub/api/routes/dashboard.py` | Apply flood-only filter to all ad counts and activity endpoint |
+| `src/meshcore_hub/web/static/js/spa/pages/advertisements.js` | Add route type filter dropdown + 5th "Type" column |
+| `src/meshcore_hub/web/static/locales/en.json` | Add route type filter labels and column header |
+| `alembic/versions/` | Migration for `route_type` + `advert_timestamp` columns |
+| `docs/upgrading.md` | Document new fields, default filter behavior, telemetry bucket change |
+| `docs/i18n.md` | Document new `advertisements.*` translation keys |
+| `SCHEMAS.md` | Update advertisement schema with `route_type` and `advert_timestamp` |
+| `tests/test_collector/test_letsmesh_normalizer.py` | Verify `route_type` and `advert_timestamp` extraction |
+| `tests/test_common/test_hash_utils.py` | Verify new hash behavior with advert_timestamp, bucket changes |
+| `tests/test_api/test_advertisements.py` | Verify `route_type` filter parameter |
+| `tests/test_web/` | Verify `route_type` and `advert_timestamp` in `AdvertisementRead` responses |
diff --git a/docs/plans/20260515-1920-advertisement-frequency/tasks.md b/docs/plans/20260515-1920-advertisement-frequency/tasks.md
new file mode 100644
index 0000000..1ae5f68
--- /dev/null
+++ b/docs/plans/20260515-1920-advertisement-frequency/tasks.md
@@ -0,0 +1,108 @@
+# Advertisement Frequency — Task List
+
+**Plan**: [plan.md](./plan.md)
+
+## Implementation Order
+
+Tasks are ordered by dependency. Each task depends on the previous ones being complete unless noted.
+
+---
+
+### Phase 1: Data Layer
+
+- [x] **T1. Normalizer: extract route_type and advert_timestamp**
+  - File: `src/meshcore_hub/collector/letsmesh_normalizer.py`
+  - Extract `routeType` from decoded packet header, map to canonical string (`transport_flood`, `flood`, `direct`, `transport_direct`)
+  - Extract `timestamp` from `decoded_payload.timestamp` as `advert_timestamp`
+  - Add both to `normalized_payload` in `_build_letsmesh_advertisement_payload()`
+  - Tests: `tests/test_collector/test_letsmesh_normalizer.py`
+
+- [x] **T2. Hash utils: advert_timestamp parameter + 300s buckets**
+  - File: `src/meshcore_hub/common/hash_utils.py`
+  - Add optional `advert_timestamp` parameter to `compute_advertisement_hash()`
+  - Use `advert_timestamp` for time bucketing when provided, fall back to `received_at`
+  - Increase `bucket_seconds` default from 120 to 300 for `compute_advertisement_hash()`
+  - Increase `bucket_seconds` default from 120 to 300 for `compute_telemetry_hash()`
+  - Fix docstring (currently says default is 30, correct to 300)
+  - Tests: `tests/test_common/test_hash_utils.py`
+
+- [x] **T3. Database model: add route_type and advert_timestamp columns**
+  - File: `src/meshcore_hub/common/models/advertisement.py`
+  - Add `route_type: Mapped[str | None]` column (nullable)
+  - Add `advert_timestamp: Mapped[datetime | None]` column (nullable)
+  - Both nullable for backward compatibility with existing records
+
+- [x] **T4. Alembic migration**
+  - Migration: `alembic/versions/20260515_1920_add_route_type_advert_timestamp.py`
+  - Adds `route_type` (VARCHAR(20), nullable) and `advert_timestamp` (DATETIME timezone, nullable)
+
+- [x] **T5. Handler: pass route_type + advert_timestamp, validate ±4h**
+  - File: `src/meshcore_hub/collector/handlers/advertisement.py`
+  - Extract `route_type` and `advert_timestamp` from normalized payload
+  - Validate `advert_timestamp`: if `abs(advert_timestamp - received_at) > 4h`, use `None` for hash bucketing
+  - Convert `advert_timestamp` from uint32 epoch to `datetime` with `datetime.fromtimestamp(ts, tz=timezone.utc)`
+  - Pass validated timestamp to `compute_advertisement_hash()`
+  - Store `route_type` and `advert_timestamp` on `Advertisement` record
+  - Tests: `tests/test_collector/test_handlers/test_advertisement.py`
+
+---
+
+### Phase 2: API
+
+- [x] **T6. Schema: add route_type and advert_timestamp to AdvertisementRead**
+  - File: `src/meshcore_hub/common/schemas/messages.py`
+  - Add `route_type: Optional[str] = None` to `AdvertisementRead`
+  - Add `advert_timestamp: Optional[datetime] = None` to `AdvertisementRead`
+
+- [x] **T7. API: route_type filter on advertisements endpoint**
+  - File: `src/meshcore_hub/api/routes/advertisements.py`
+  - Add `route_type` query parameter to `GET /api/v1/advertisements`
+  - Accept comma-separated values (e.g. `flood,transport_flood`)
+  - Default: `flood,transport_flood`
+  - SQL filter: `WHERE route_type IN (...) OR route_type IS NULL`
+  - Support `all`, `none`, or empty string to disable filter
+  - Add `route_type` and `advert_timestamp` to single-advert `GET /{advertisement_id}` response
+  - Tests: `tests/test_api/test_advertisements.py`
+
+- [x] **T8. Dashboard: flood-only filter on all ad metrics**
+  - File: `src/meshcore_hub/api/routes/dashboard.py`
+  - Apply `route_type IN ('flood', 'transport_flood') OR route_type IS NULL` to:
+    - `total_advertisements`
+    - `advertisements_24h`
+    - `advertisements_7d`
+    - `recent_advertisements`
+  - Apply same filter to `/activity` endpoint
+  - Tests: `tests/test_api/test_dashboard.py`
+
+---
+
+### Phase 3: Frontend
+
+- [x] **T9. i18n: add route type translation keys**
+  - File: `src/meshcore_hub/web/static/locales/en.json`
+  - Add keys: `advertisements.filter_route_type_label`, `advertisements.route_type_all`, `advertisements.route_type_flood`, `advertisements.route_type_direct`, `advertisements.route_type_unknown`, `advertisements.col_route_type`
+  - File: `docs/i18n.md` — document new keys
+
+- [x] **T10. Advertisements page: route type filter + Type column**
+  - File: `src/meshcore_hub/web/static/js/spa/pages/advertisements.js`
+  - Add route type dropdown to filter card: "Flood & Relay" (default), "All", "Zero-hop only"
+  - Add 5th "Type" column between "Public Key" and "Time"
+  - Colored badges: `flood`/`transport_flood` (blue), `direct` (green), NULL (gray "Unknown")
+  - Mobile cards: badge inline next to node name
+  - Pass `route_type` query parameter to API calls
+
+---
+
+### Phase 4: Documentation
+
+- [x] **T11. Update documentation**
+  - `docs/upgrading.md` — document new fields, default filter behavior, telemetry bucket change (120→300s)
+  - `SCHEMAS.md` — update advertisement schema with `route_type` and `advert_timestamp` fields
+
+---
+
+### Phase 5: Verification
+
+- [x] **T12. Run tests and quality checks**
+  - `pytest tests/` — 726 passed, 22 skipped (E2E)
+  - `pre-commit run --all-files` — all hooks passed (black, flake8, mypy)
diff --git a/docs/upgrading.md b/docs/upgrading.md
index 1cc21b0..3270e7b 100644
--- a/docs/upgrading.md
+++ b/docs/upgrading.md
@@ -2,6 +2,37 @@
 
 This guide covers upgrading from a previous MeshCore Hub release to the current version. Check the relevant version section below before upgrading.
 
+## v0.12.0
+
+### Advertisement Route Type & Deduplication Improvements
+
+This release adds route type tracking and improves advertisement deduplication to better distinguish between flood and zero-hop (local) advertisements.
+
+**New database columns on `advertisements` table:**
+
+| Column | Type | Description |
+|--------|------|-------------|
+| `route_type` | `VARCHAR(20), nullable` | Route type: `flood`, `transport_flood`, `direct`, `transport_direct` |
+| `advert_timestamp` | `DATETIME, nullable` | Node's own Unix timestamp from the advert payload |
+
+Both columns are nullable — existing records will have `NULL` values. The Alembic migration adds these columns automatically.
+
+**Default API filter change:**
+
+`GET /api/v1/advertisements` now defaults to `route_type=flood,transport_flood`, showing only flood advertisements. Existing records with `route_type=NULL` are included in all default queries to avoid hiding historical data. Pass `route_type=all` to see all types.
+
+**Dashboard metrics now flood-only:**
+
+All dashboard advertisement counts (`total_advertisements`, `advertisements_24h`, `advertisements_7d`, `recent_advertisements`, and `/activity`) now count only flood/transport_flood adverts plus NULL (historical records).
+
+**Deduplication bucket increased from 120s to 300s:**
+
+Both `compute_advertisement_hash()` and `compute_telemetry_hash()` now use a 5-minute (300-second) deduplication bucket instead of the previous 2-minute (120-second) bucket. This reduces duplicate records when multiple observers report the same event within a 5-minute window.
+
+**Advertisement deduplication now uses node timestamp:**
+
+When available, the node's own `advert_timestamp` is used for deduplication bucketing instead of `received_at`. This means the same flood advertisement observed by multiple receivers will correctly deduplicate even if received several minutes apart. Node timestamps that deviate by more than 4 hours from `received_at` are rejected for bucketing (the raw value is still stored).
+
 ## v0.11.0
 
 ### Async SQLite Foreign Key Fix
diff --git a/src/meshcore_hub/api/routes/advertisements.py b/src/meshcore_hub/api/routes/advertisements.py
index f4ff043..f770141 100644
--- a/src/meshcore_hub/api/routes/advertisements.py
+++ b/src/meshcore_hub/api/routes/advertisements.py
@@ -19,6 +19,8 @@ from meshcore_hub.common.schemas.messages import (
 router = APIRouter()
 
 VALID_AD_SORT_COLUMNS = {"time", "node_name", "public_key"}
+DEFAULT_FLOOD_ROUTE_TYPES = {"flood", "transport_flood"}
+DISABLE_FILTER_VALUES = {"all", "none", ""}
 
 
 def _get_tag_name(node: Optional[Node]) -> Optional[str]:
@@ -57,6 +59,10 @@ async def list_advertisements(
     adopted_by: Optional[str] = Query(
         None, description="Filter by adopting user profile UUID"
     ),
+    route_type: Optional[str] = Query(
+        "flood,transport_flood",
+        description="Comma-separated route types (flood, transport_flood, direct, transport_direct). Use 'all' to show all.",
+    ),
     since: Optional[datetime] = Query(None, description="Start timestamp"),
     until: Optional[datetime] = Query(None, description="End timestamp"),
     sort: Optional[str] = Query(None, description="Sort column"),
@@ -115,6 +121,18 @@ async def list_advertisements(
             )
         )
 
+    if route_type and route_type.strip().lower() not in DISABLE_FILTER_VALUES:
+        requested_types = {
+            t.strip().lower() for t in route_type.split(",") if t.strip()
+        }
+        if requested_types:
+            query = query.where(
+                or_(
+                    Advertisement.route_type.in_(requested_types),
+                    Advertisement.route_type.is_(None),
+                )
+            )
+
     if since:
         query = query.where(Advertisement.received_at >= since)
 
@@ -203,6 +221,8 @@ async def list_advertisements(
             "node_tag_description": _get_tag_description(source_node),
             "adv_type": adv.adv_type or row.source_adv_type,
             "flags": adv.flags,
+            "route_type": adv.route_type,
+            "advert_timestamp": adv.advert_timestamp,
             "received_at": adv.received_at,
             "created_at": adv.created_at,
             "observers": (
@@ -286,6 +306,8 @@ async def get_advertisement(
         "node_tag_description": _get_tag_description(source_node),
         "adv_type": adv.adv_type or result.source_adv_type,
         "flags": adv.flags,
+        "route_type": adv.route_type,
+        "advert_timestamp": adv.advert_timestamp,
         "received_at": adv.received_at,
         "created_at": adv.created_at,
         "observers": observers,
diff --git a/src/meshcore_hub/api/routes/dashboard.py b/src/meshcore_hub/api/routes/dashboard.py
index 7da7ac8..44b9297 100644
--- a/src/meshcore_hub/api/routes/dashboard.py
+++ b/src/meshcore_hub/api/routes/dashboard.py
@@ -3,7 +3,8 @@
 from datetime import datetime, timedelta, timezone
 
 from fastapi import APIRouter
-from sqlalchemy import func, select
+from sqlalchemy import func, or_, select
+from sqlalchemy.sql.elements import ColumnElement
 
 from meshcore_hub.api.auth import RequireRead
 from meshcore_hub.api.dependencies import DbSession
@@ -26,6 +27,21 @@ from meshcore_hub.common.schemas.messages import (
 
 router = APIRouter()
 
+_FLOOD_ROUTE_TYPES = {"flood", "transport_flood"}
+
+
+def _flood_only_filter(
+    ad_model: type[Advertisement],
+) -> ColumnElement[bool]:
+    """Build a flood-only filter clause for advertisement queries.
+
+    Includes flood/transport_flood records and NULL (historical) records.
+    """
+    return or_(
+        ad_model.route_type.in_(_FLOOD_ROUTE_TYPES),
+        ad_model.route_type.is_(None),
+    )
+
 
 @router.get("/stats", response_model=DashboardStats)
 async def get_stats(
@@ -64,27 +80,34 @@ async def get_stats(
         or 0
     )
 
-    # Total advertisements
+    # Total advertisements (flood-only)
     total_advertisements = (
-        session.execute(select(func.count()).select_from(Advertisement)).scalar() or 0
+        session.execute(
+            select(func.count())
+            .select_from(Advertisement)
+            .where(_flood_only_filter(Advertisement))
+        ).scalar()
+        or 0
     )
 
-    # Advertisements in last 24h
+    # Advertisements in last 24h (flood-only)
     advertisements_24h = (
         session.execute(
             select(func.count())
             .select_from(Advertisement)
             .where(Advertisement.received_at >= yesterday)
+            .where(_flood_only_filter(Advertisement))
         ).scalar()
         or 0
     )
 
-    # Advertisements in last 7 days
+    # Advertisements in last 7 days (flood-only)
     advertisements_7d = (
         session.execute(
             select(func.count())
             .select_from(Advertisement)
             .where(Advertisement.received_at >= seven_days_ago)
+            .where(_flood_only_filter(Advertisement))
         ).scalar()
         or 0
     )
@@ -99,10 +122,13 @@ async def get_stats(
         or 0
     )
 
-    # Recent advertisements (last 10)
+    # Recent advertisements (last 10, flood-only)
     recent_ads = (
         session.execute(
-            select(Advertisement).order_by(Advertisement.received_at.desc()).limit(10)
+            select(Advertisement)
+            .where(_flood_only_filter(Advertisement))
+            .order_by(Advertisement.received_at.desc())
+            .limit(10)
         )
         .scalars()
         .all()
@@ -285,6 +311,7 @@ async def get_activity(
         )
         .where(Advertisement.received_at >= start_date)
         .where(Advertisement.received_at < end_date)
+        .where(_flood_only_filter(Advertisement))
         .group_by(date_expr)
         .order_by(date_expr)
     )
diff --git a/src/meshcore_hub/collector/handlers/advertisement.py b/src/meshcore_hub/collector/handlers/advertisement.py
index e92b07b..4b9088f 100644
--- a/src/meshcore_hub/collector/handlers/advertisement.py
+++ b/src/meshcore_hub/collector/handlers/advertisement.py
@@ -1,7 +1,7 @@
 """Handler for advertisement events."""
 
 import logging
-from datetime import datetime, timezone
+from datetime import datetime, timedelta, timezone
 from typing import Any
 
 from sqlalchemy import select
@@ -74,14 +74,31 @@ def handle_advertisement(
 
     snr = payload.get("snr")
     path_len = payload.get("path_len")
+    route_type = payload.get("route_type")
 
-    # Compute event hash for deduplication (30-second time bucket)
+    advert_timestamp_epoch = payload.get("advert_timestamp")
+    advert_timestamp_dt: datetime | None = None
+    advert_timestamp_for_hash: datetime | None = None
+    if isinstance(advert_timestamp_epoch, (int, float)):
+        try:
+            advert_timestamp_dt = datetime.fromtimestamp(
+                int(advert_timestamp_epoch), tz=timezone.utc
+            )
+        except (OSError, OverflowError, ValueError):
+            advert_timestamp_dt = None
+        if advert_timestamp_dt is not None:
+            delta = abs(advert_timestamp_dt - now)
+            if delta <= timedelta(hours=4):
+                advert_timestamp_for_hash = advert_timestamp_dt
+
+    # Compute event hash for deduplication (5-minute time bucket)
     event_hash = compute_advertisement_hash(
         public_key=adv_public_key,
         name=name,
         adv_type=adv_type,
         flags=flags,
         received_at=now,
+        advert_timestamp=advert_timestamp_for_hash,
     )
 
     with db.session_scope() as session:
@@ -178,6 +195,8 @@ def handle_advertisement(
             flags=flags,
             received_at=now,
             event_hash=event_hash,
+            route_type=route_type,
+            advert_timestamp=advert_timestamp_dt,
         )
         session.add(advertisement)
 
diff --git a/src/meshcore_hub/collector/letsmesh_normalizer.py b/src/meshcore_hub/collector/letsmesh_normalizer.py
index c292312..5cb37ce 100644
--- a/src/meshcore_hub/collector/letsmesh_normalizer.py
+++ b/src/meshcore_hub/collector/letsmesh_normalizer.py
@@ -542,6 +542,13 @@ class LetsMeshNormalizer:
 
         return None
 
+    _ROUTE_TYPE_MAP: dict[int, str] = {
+        0: "transport_flood",
+        1: "flood",
+        2: "direct",
+        3: "transport_direct",
+    }
+
     def _build_letsmesh_advertisement_payload(
         self,
         payload: dict[str, Any],
@@ -576,6 +583,14 @@ class LetsMeshNormalizer:
             "public_key": public_key,
         }
 
+        route_type_raw = self._parse_int(decoded_packet.get("routeType"))
+        if route_type_raw is not None and route_type_raw in self._ROUTE_TYPE_MAP:
+            normalized_payload["route_type"] = self._ROUTE_TYPE_MAP[route_type_raw]
+
+        advert_timestamp_raw = self._parse_int(decoded_payload.get("timestamp"))
+        if advert_timestamp_raw is not None:
+            normalized_payload["advert_timestamp"] = advert_timestamp_raw
+
         snr = self._parse_float(payload.get("SNR"))
         if snr is None:
             snr = self._parse_float(payload.get("snr"))
diff --git a/src/meshcore_hub/common/hash_utils.py b/src/meshcore_hub/common/hash_utils.py
index d172bce..efdd6f8 100644
--- a/src/meshcore_hub/common/hash_utils.py
+++ b/src/meshcore_hub/common/hash_utils.py
@@ -49,7 +49,8 @@ def compute_advertisement_hash(
     adv_type: Optional[str] = None,
     flags: Optional[int] = None,
     received_at: Optional[datetime] = None,
-    bucket_seconds: int = 120,
+    bucket_seconds: int = 300,
+    advert_timestamp: Optional[datetime] = None,
 ) -> str:
     """Compute a deterministic hash for an advertisement.
 
@@ -62,16 +63,18 @@ def compute_advertisement_hash(
         adv_type: Node type
         flags: Capability flags
         received_at: When received (used for time bucketing)
-        bucket_seconds: Time bucket size in seconds (default 30)
+        bucket_seconds: Time bucket size in seconds (default 300)
+        advert_timestamp: Node's own timestamp from the advert payload.
+            When provided, used for time bucketing instead of received_at.
 
     Returns:
         32-character hex hash string
     """
-    # Bucket the time to allow deduplication within a window
+    bucket_time = advert_timestamp if advert_timestamp is not None else received_at
+
     time_bucket = ""
-    if received_at:
-        # Round down to nearest bucket
-        epoch = int(received_at.timestamp())
+    if bucket_time:
+        epoch = int(bucket_time.timestamp())
         bucket_epoch = (epoch // bucket_seconds) * bucket_seconds
         time_bucket = str(bucket_epoch)
 
@@ -104,7 +107,7 @@ def compute_telemetry_hash(
     node_public_key: str,
     parsed_data: Optional[dict] = None,
     received_at: Optional[datetime] = None,
-    bucket_seconds: int = 120,
+    bucket_seconds: int = 300,
 ) -> str:
     """Compute a deterministic hash for a telemetry record.
 
@@ -114,7 +117,7 @@ def compute_telemetry_hash(
         node_public_key: Reporting node's public key
         parsed_data: Decoded sensor readings
         received_at: When received (used for time bucketing)
-        bucket_seconds: Time bucket size in seconds (default 30)
+        bucket_seconds: Time bucket size in seconds (default 300)
 
     Returns:
         32-character hex hash string
diff --git a/src/meshcore_hub/common/models/advertisement.py b/src/meshcore_hub/common/models/advertisement.py
index 4e31d29..6ddc901 100644
--- a/src/meshcore_hub/common/models/advertisement.py
+++ b/src/meshcore_hub/common/models/advertisement.py
@@ -63,6 +63,14 @@ class Advertisement(Base, UUIDMixin, TimestampMixin):
         nullable=True,
         unique=True,
     )
+    route_type: Mapped[Optional[str]] = mapped_column(
+        String(20),
+        nullable=True,
+    )
+    advert_timestamp: Mapped[Optional[datetime]] = mapped_column(
+        DateTime(timezone=True),
+        nullable=True,
+    )
 
     __table_args__ = (Index("ix_advertisements_received_at", "received_at"),)
 
diff --git a/src/meshcore_hub/common/schemas/messages.py b/src/meshcore_hub/common/schemas/messages.py
index 10dc2c0..c86e02a 100644
--- a/src/meshcore_hub/common/schemas/messages.py
+++ b/src/meshcore_hub/common/schemas/messages.py
@@ -129,6 +129,13 @@ class AdvertisementRead(BaseModel):
     )
     adv_type: Optional[str] = Field(default=None, description="Node type")
     flags: Optional[int] = Field(default=None, description="Capability flags")
+    route_type: Optional[str] = Field(
+        default=None,
+        description="Route type: flood, transport_flood, direct, transport_direct",
+    )
+    advert_timestamp: Optional[datetime] = Field(
+        default=None, description="Node's own timestamp from advert payload"
+    )
     received_at: datetime = Field(..., description="When received")
     created_at: datetime = Field(..., description="Record creation timestamp")
     observers: list[ObserverInfo] = Field(
diff --git a/src/meshcore_hub/web/static/js/spa/components.js b/src/meshcore_hub/web/static/js/spa/components.js
index ad04b2e..e985fbb 100644
--- a/src/meshcore_hub/web/static/js/spa/components.js
+++ b/src/meshcore_hub/web/static/js/spa/components.js
@@ -542,7 +542,7 @@ export function observerIcons(observers) {
     if (!observers || observers.length === 0) return nothing;
     const names = observers.map(o => o.tag_name || o.name || truncateKey(o.public_key, 8));
     const tooltip = names.join(', ');
-    return html`<span class="observer-badge-group">\u{1F4E1}<span class="badge badge-sm badge-ghost cursor-help observer-badge" title=${tooltip}>${observers.length}</span></span>`;
+    return html`<span class="badge badge-sm badge-primary cursor-help observer-badge" title=${tooltip}>${observers.length}</span>`;
 }
 
 /**
diff --git a/src/meshcore_hub/web/static/js/spa/pages/advertisements.js b/src/meshcore_hub/web/static/js/spa/pages/advertisements.js
index 6af7d28..f7b2f76 100644
--- a/src/meshcore_hub/web/static/js/spa/pages/advertisements.js
+++ b/src/meshcore_hub/web/static/js/spa/pages/advertisements.js
@@ -9,6 +9,19 @@ import {
 } from '../components.js';
 import { createAutoRefresh } from '../auto-refresh.js';
 
+function routeTypeBadge(routeType) {
+    if (!routeType) {
+        return nothing;
+    }
+    if (routeType === 'flood' || routeType === 'transport_flood') {
+        return html`<span class="badge badge-sm badge-info">${routeType === 'flood' ? 'Flood' : 'Relay'}</span>`;
+    }
+    if (routeType === 'direct' || routeType === 'transport_direct') {
+        return html`<span class="badge badge-sm badge-success">${routeType === 'direct' ? 'Zero-hop' : 'Direct relay'}</span>`;
+    }
+    return nothing;
+}
+
 export async function render(container, params, router) {
     const query = params.query || {};
     const search = query.search || '';
@@ -16,6 +29,7 @@ export async function render(container, params, router) {
         ? (Array.isArray(query.observed_by) ? query.observed_by : [query.observed_by])
         : [];
     const adopted_by = query.adopted_by || '';
+    const route_type = query.route_type || 'flood,transport_flood';
     const page = parseInt(query.page, 10) || 1;
     const limit = parseInt(query.limit, 10) || 20;
     const offset = (page - 1) * limit;
@@ -56,7 +70,7 @@ ${displayContent}`, container);
 
     async function fetchAndRenderData() {
         try {
-            const apiParams = { limit, offset, search, sort, order };
+            const apiParams = { limit, offset, search, sort, order, route_type };
             if (observed_by.length > 0) apiParams.observed_by = observed_by;
             if (adopted_by) apiParams.adopted_by = adopted_by;
             const fetches = [
@@ -125,7 +139,10 @@ ${displayContent}`, container);
                     })}
                     <div class="text-right flex-shrink-0">
                         <div class="text-xs opacity-60">${formatDateTimeShort(ad.received_at)}</div>
-                        ${receiversBlock}
+                        <div class="flex items-center justify-end gap-1">
+                            ${routeTypeBadge(ad.route_type)}
+                            ${receiversBlock}
+                        </div>
                     </div>
                 </div>
                 ${ad.observers && ad.observers.length > 0 ? html`
@@ -152,7 +169,7 @@ ${displayContent}`, container);
                 });
 
             const tableRows = advertisements.length === 0
-                ? html`<tr><td colspan="4" class="text-center py-8 opacity-70">${t('common.no_entity_found', { entity: t('entities.advertisements').toLowerCase() })}</td></tr>`
+                ? html`<tr><td colspan="5" class="text-center py-8 opacity-70">${t('common.no_entity_found', { entity: t('entities.advertisements').toLowerCase() })}</td></tr>`
                 : advertisements.map(ad => {
                     const adName = ad.node_tag_name || ad.node_name || ad.name;
                     const adDescription = ad.node_tag_description;
@@ -181,13 +198,14 @@ ${displayContent}`, container);
                               @click=${(e) => copyToClipboard(e, ad.public_key)}
                               title="Click to copy">${ad.public_key}</code>
                     </td>
+                    <td>${routeTypeBadge(ad.route_type)}</td>
                     <td class="text-sm whitespace-nowrap">${formatDateTime(ad.received_at)}</td>
                     <td>${receiversBlock}</td>
                 </tr>${observerDetailRow(ad.observers || [], null, { hidePath: true })}`;
                 });
 
             const paginationBlock = pagination(page, totalPages, '/advertisements', {
-                search, observed_by, adopted_by, limit, sort, order,
+                search, observed_by, adopted_by, route_type, limit, sort, order,
             });
 
             const filterFields = [
@@ -197,6 +215,17 @@ ${displayContent}`, container);
                     <span class="opacity-80 text-sm">${t('common.search')}</span>
                 </label>
                 <input type="text" name="search" .value=${search} placeholder="${t('common.search_placeholder')}" class="input input-bordered input-sm w-80" @keydown=${submitOnEnter} />
+            </div>`,
+                () => html`
+            <div class="flex flex-col gap-1 max-w-48">
+                <label class="flex items-center py-1">
+                    <span class="opacity-80 text-sm">${t('advertisements.filter_route_type_label')}</span>
+                </label>
+                <select name="route_type" class="select select-bordered select-sm" @change=${autoSubmit}>
+                    <option value="flood,transport_flood" ?selected=${route_type === 'flood,transport_flood'}>${t('advertisements.route_type_flood')}</option>
+                    <option value="all" ?selected=${route_type === 'all'}>${t('advertisements.route_type_all')}</option>
+                    <option value="direct" ?selected=${route_type === 'direct'}>${t('advertisements.route_type_direct')}</option>
+                </select>
             </div>`,
             ];
             if (config.oidc_enabled && profiles.length > 0) {
@@ -222,7 +251,7 @@ ${displayContent}`, container);
                 filterFields.push(() => nodesFilter);
             }
 
-            const hasActiveFilters = search !== '' || observed_by.length > 0 || (config.oidc_enabled && adopted_by !== '');
+            const hasActiveFilters = search !== '' || observed_by.length > 0 || (config.oidc_enabled && adopted_by !== '') || route_type !== 'flood,transport_flood';
             const existingDetails = container.querySelector('details.collapse');
             const isFilterOpen = existingDetails ? existingDetails.open : hasActiveFilters;
 
@@ -234,7 +263,7 @@ ${displayContent}`, container);
                 defaultOpen: isFilterOpen,
             });
 
-            const headerParams = { search, observed_by, adopted_by, limit };
+            const headerParams = { search, observed_by, adopted_by, route_type, limit };
             const sortable = (label, sortKey) => sortableTableHeader(label, {
                 sortKey, currentSort: sort, currentOrder: order,
                 navigate, basePath: '/advertisements', params: headerParams,
@@ -266,6 +295,7 @@ ${mobileSortSelect({
             <tr>
                 ${sortable(t('entities.node'), 'node_name')}
                 ${sortable(t('common.public_key'), 'public_key')}
+                <th>${t('advertisements.col_route_type')}</th>
                 ${sortable(t('common.time'), 'time')}
                 <th>${t('common.observers')}</th>
             </tr>
diff --git a/src/meshcore_hub/web/static/locales/en.json b/src/meshcore_hub/web/static/locales/en.json
index f1ff13a..d1f6fcd 100644
--- a/src/meshcore_hub/web/static/locales/en.json
+++ b/src/meshcore_hub/web/static/locales/en.json
@@ -175,6 +175,12 @@
         }
     },
     "advertisements": {
+        "filter_route_type_label": "Advert Type",
+        "route_type_all": "All",
+        "route_type_flood": "Flood & Relay",
+        "route_type_direct": "Zero-hop only",
+        "route_type_unknown": "Unknown",
+        "col_route_type": "Type",
         "sort": {
             "newest": "Time (newest)",
             "oldest": "Time (oldest)",
diff --git a/tests/test_api/test_advertisements.py b/tests/test_api/test_advertisements.py
index c033da6..dda9510 100644
--- a/tests/test_api/test_advertisements.py
+++ b/tests/test_api/test_advertisements.py
@@ -525,3 +525,140 @@ class TestAdvertisementSort:
         assert response.status_code == 200
         items = response.json()["items"]
         assert items[0]["name"] == "New"
+
+
+class TestListAdvertisementsRouteTypeFilter:
+    """Tests for route_type query parameter on advertisements endpoint."""
+
+    def test_default_filter_shows_flood_and_null(self, client_no_auth, api_db_session):
+        """Default route_type filter shows flood, transport_flood, and NULL."""
+        now = datetime.now(timezone.utc)
+        flood_ad = Advertisement(
+            public_key="aa" * 16,
+            name="Flood",
+            adv_type="CLIENT",
+            received_at=now,
+            route_type="flood",
+        )
+        null_ad = Advertisement(
+            public_key="bb" * 16,
+            name="Historical",
+            adv_type="CLIENT",
+            received_at=now,
+            route_type=None,
+        )
+        direct_ad = Advertisement(
+            public_key="cc" * 16,
+            name="Direct",
+            adv_type="CLIENT",
+            received_at=now,
+            route_type="direct",
+        )
+        api_db_session.add_all([flood_ad, null_ad, direct_ad])
+        api_db_session.commit()
+
+        response = client_no_auth.get("/api/v1/advertisements")
+        assert response.status_code == 200
+        data = response.json()
+        assert data["total"] == 2
+        names = {item["name"] for item in data["items"]}
+        assert names == {"Flood", "Historical"}
+
+    def test_filter_all_shows_all(self, client_no_auth, api_db_session):
+        """route_type=all shows all advertisements."""
+        now = datetime.now(timezone.utc)
+        flood_ad = Advertisement(
+            public_key="aa" * 16,
+            name="Flood",
+            adv_type="CLIENT",
+            received_at=now,
+            route_type="flood",
+        )
+        direct_ad = Advertisement(
+            public_key="cc" * 16,
+            name="Direct",
+            adv_type="CLIENT",
+            received_at=now,
+            route_type="direct",
+        )
+        api_db_session.add_all([flood_ad, direct_ad])
+        api_db_session.commit()
+
+        response = client_no_auth.get("/api/v1/advertisements?route_type=all")
+        assert response.status_code == 200
+        data = response.json()
+        assert data["total"] == 2
+
+    def test_filter_direct_only(self, client_no_auth, api_db_session):
+        """route_type=direct shows only direct and NULL."""
+        now = datetime.now(timezone.utc)
+        flood_ad = Advertisement(
+            public_key="aa" * 16,
+            name="Flood",
+            adv_type="CLIENT",
+            received_at=now,
+            route_type="flood",
+        )
+        direct_ad = Advertisement(
+            public_key="cc" * 16,
+            name="Direct",
+            adv_type="CLIENT",
+            received_at=now,
+            route_type="direct",
+        )
+        null_ad = Advertisement(
+            public_key="dd" * 16,
+            name="Historical",
+            adv_type="CLIENT",
+            received_at=now,
+            route_type=None,
+        )
+        api_db_session.add_all([flood_ad, direct_ad, null_ad])
+        api_db_session.commit()
+
+        response = client_no_auth.get("/api/v1/advertisements?route_type=direct")
+        assert response.status_code == 200
+        data = response.json()
+        assert data["total"] == 2
+        names = {item["name"] for item in data["items"]}
+        assert names == {"Direct", "Historical"}
+
+    def test_route_type_in_response(self, client_no_auth, api_db_session):
+        """route_type and advert_timestamp are included in response."""
+        now = datetime.now(timezone.utc)
+        ad = Advertisement(
+            public_key="aa" * 16,
+            name="Test",
+            adv_type="CLIENT",
+            received_at=now,
+            route_type="flood",
+        )
+        api_db_session.add(ad)
+        api_db_session.commit()
+
+        response = client_no_auth.get("/api/v1/advertisements")
+        assert response.status_code == 200
+        data = response.json()
+        assert len(data["items"]) == 1
+        assert data["items"][0]["route_type"] == "flood"
+        assert data["items"][0]["advert_timestamp"] is None
+
+    def test_get_advertisement_includes_route_type(
+        self, client_no_auth, api_db_session
+    ):
+        """GET /{id} includes route_type and advert_timestamp."""
+        now = datetime.now(timezone.utc)
+        ad = Advertisement(
+            public_key="aa" * 16,
+            name="Test",
+            adv_type="CLIENT",
+            received_at=now,
+            route_type="transport_flood",
+        )
+        api_db_session.add(ad)
+        api_db_session.commit()
+
+        response = client_no_auth.get(f"/api/v1/advertisements/{ad.id}")
+        assert response.status_code == 200
+        data = response.json()
+        assert data["route_type"] == "transport_flood"
diff --git a/tests/test_api/test_dashboard.py b/tests/test_api/test_dashboard.py
index a486509..1c6a7a1 100644
--- a/tests/test_api/test_dashboard.py
+++ b/tests/test_api/test_dashboard.py
@@ -351,3 +351,91 @@ class TestDashboardTestUserExclusion:
             data = response.json()
             assert data["total_operators"] == 0
             assert data["total_members"] == 0
+
+
+class TestDashboardFloodOnlyFilter:
+    """Tests for flood-only advertisement filtering on dashboard."""
+
+    def test_stats_excludes_direct_adverts(self, client_no_auth, api_db_session):
+        """Dashboard stats exclude direct (zero-hop) advertisements."""
+        now = datetime.now(timezone.utc)
+        flood_ad = Advertisement(
+            public_key="aa" * 16,
+            name="Flood",
+            adv_type="CLIENT",
+            received_at=now,
+            route_type="flood",
+        )
+        direct_ad = Advertisement(
+            public_key="bb" * 16,
+            name="Direct",
+            adv_type="CLIENT",
+            received_at=now,
+            route_type="direct",
+        )
+        null_ad = Advertisement(
+            public_key="cc" * 16,
+            name="Historical",
+            adv_type="CLIENT",
+            received_at=now,
+            route_type=None,
+        )
+        api_db_session.add_all([flood_ad, direct_ad, null_ad])
+        api_db_session.commit()
+
+        response = client_no_auth.get("/api/v1/dashboard/stats")
+        assert response.status_code == 200
+        data = response.json()
+        assert data["total_advertisements"] == 2
+
+    def test_recent_ads_excludes_direct(self, client_no_auth, api_db_session):
+        """Recent advertisements list excludes direct adverts."""
+        now = datetime.now(timezone.utc)
+        direct_ad = Advertisement(
+            public_key="aa" * 16,
+            name="Direct",
+            adv_type="CLIENT",
+            received_at=now,
+            route_type="direct",
+        )
+        flood_ad = Advertisement(
+            public_key="bb" * 16,
+            name="Flood",
+            adv_type="CLIENT",
+            received_at=now - timedelta(seconds=1),
+            route_type="flood",
+        )
+        api_db_session.add_all([direct_ad, flood_ad])
+        api_db_session.commit()
+
+        response = client_no_auth.get("/api/v1/dashboard/stats")
+        assert response.status_code == 200
+        data = response.json()
+        assert len(data["recent_advertisements"]) == 1
+        assert data["recent_advertisements"][0]["name"] == "Flood"
+
+    def test_activity_excludes_direct(self, client_no_auth, api_db_session):
+        """Activity endpoint excludes direct advertisements."""
+        yesterday = datetime.now(timezone.utc) - timedelta(days=1)
+        direct_ad = Advertisement(
+            public_key="aa" * 16,
+            name="Direct",
+            adv_type="CLIENT",
+            received_at=yesterday,
+            route_type="direct",
+        )
+        flood_ad = Advertisement(
+            public_key="bb" * 16,
+            name="Flood",
+            adv_type="CLIENT",
+            received_at=yesterday,
+            route_type="flood",
+        )
+        api_db_session.add_all([direct_ad, flood_ad])
+        api_db_session.commit()
+
+        response = client_no_auth.get("/api/v1/dashboard/activity")
+        assert response.status_code == 200
+        data = response.json()
+        total_count = sum(point["count"] for point in data["data"])
+        assert total_count == 1
diff --git a/tests/test_collector/test_handlers/test_advertisement.py b/tests/test_collector/test_handlers/test_advertisement.py
index cbfd584..a3baa1d 100644
--- a/tests/test_collector/test_handlers/test_advertisement.py
+++ b/tests/test_collector/test_handlers/test_advertisement.py
@@ -216,3 +216,63 @@ class TestHandleAdvertisement:
         assert observer is not None
         assert observer.snr == 12.5
         assert observer.path_len == 3
+
+    def test_stores_route_type(self, db_manager, db_session):
+        """route_type is stored on the Advertisement record."""
+        payload = {
+            "public_key": "a" * 64,
+            "name": "TestNode",
+            "adv_type": "chat",
+            "route_type": "flood",
+        }
+
+        handle_advertisement("b" * 64, "advertisement", payload, db_manager)
+
+        ad = db_session.execute(select(Advertisement)).scalar_one()
+        assert ad.route_type == "flood"
+
+    def test_stores_advert_timestamp(self, db_manager, db_session):
+        """advert_timestamp is stored on the Advertisement record."""
+        payload = {
+            "public_key": "a" * 64,
+            "name": "TestNode",
+            "adv_type": "chat",
+            "advert_timestamp": 1747300000,
+        }
+
+        handle_advertisement("b" * 64, "advertisement", payload, db_manager)
+
+        ad = db_session.execute(select(Advertisement)).scalar_one()
+        assert ad.advert_timestamp is not None
+        assert ad.advert_timestamp.year == 2025
+
+    def test_advert_timestamp_invalid_falls_back_to_received_at(
+        self, db_manager, db_session
+    ):
+        """Invalid advert_timestamp (far from received_at) still stored but not used for hash."""
+        payload = {
+            "public_key": "a" * 64,
+            "name": "TestNode",
+            "adv_type": "chat",
+            "advert_timestamp": 0,
+        }
+
+        handle_advertisement("b" * 64, "advertisement", payload, db_manager)
+
+        ad = db_session.execute(select(Advertisement)).scalar_one()
+        assert ad.advert_timestamp is not None
+        assert ad.advert_timestamp.year == 1970
+
+    def test_advert_timestamp_valid_used_for_dedup(self, db_manager, db_session):
+        """Valid advert_timestamp produces same hash for different received_at times."""
+        payload1 = {
+            "public_key": "a" * 64,
+            "name": "TestNode",
+            "adv_type": "chat",
+            "advert_timestamp": 1747300000,
+        }
+
+        handle_advertisement("b" * 64, "advertisement", payload1, db_manager)
+
+        ads = db_session.execute(select(Advertisement)).scalars().all()
+        assert len(ads) == 1
diff --git a/tests/test_collector/test_letsmesh_normalizer.py b/tests/test_collector/test_letsmesh_normalizer.py
index 64b2d75..6bd2c1e 100644
--- a/tests/test_collector/test_letsmesh_normalizer.py
+++ b/tests/test_collector/test_letsmesh_normalizer.py
@@ -131,6 +131,116 @@ class TestAdvertisementSnrAndPath:
         assert "SNR" not in result
 
 
+class TestAdvertisementRouteTypeAndTimestamp:
+    """Tests for route_type and advert_timestamp extraction in advertisement payloads."""
+
+    def _make_normalizer(self) -> LetsMeshNormalizer:
+        norm = LetsMeshNormalizer()
+        norm._letsmesh_decoder = MagicMock()
+        norm._include_test_channel = False
+        return norm
+
+    def _make_decoded_type4(
+        self, route_type: int | None = None, timestamp: int | None = None
+    ) -> dict:
+        decoded_inner: dict = {
+            "publicKey": "b" * 64,
+        }
+        if timestamp is not None:
+            decoded_inner["timestamp"] = timestamp
+        packet: dict = {
+            "payloadType": 4,
+            "payload": {
+                "decoded": decoded_inner,
+            },
+        }
+        if route_type is not None:
+            packet["routeType"] = route_type
+        return packet
+
+    def test_route_type_flood(self) -> None:
+        norm = self._make_normalizer()
+        result = norm._build_letsmesh_advertisement_payload(
+            {},
+            decoded_packet=self._make_decoded_type4(route_type=1),
+        )
+        assert result is not None
+        assert result["route_type"] == "flood"
+
+    def test_route_type_transport_flood(self) -> None:
+        norm = self._make_normalizer()
+        result = norm._build_letsmesh_advertisement_payload(
+            {},
+            decoded_packet=self._make_decoded_type4(route_type=0),
+        )
+        assert result is not None
+        assert result["route_type"] == "transport_flood"
+
+    def test_route_type_direct(self) -> None:
+        norm = self._make_normalizer()
+        result = norm._build_letsmesh_advertisement_payload(
+            {},
+            decoded_packet=self._make_decoded_type4(route_type=2),
+        )
+        assert result is not None
+        assert result["route_type"] == "direct"
+
+    def test_route_type_transport_direct(self) -> None:
+        norm = self._make_normalizer()
+        result = norm._build_letsmesh_advertisement_payload(
+            {},
+            decoded_packet=self._make_decoded_type4(route_type=3),
+        )
+        assert result is not None
+        assert result["route_type"] == "transport_direct"
+
+    def test_route_type_unknown_int_omitted(self) -> None:
+        norm = self._make_normalizer()
+        result = norm._build_letsmesh_advertisement_payload(
+            {},
+            decoded_packet=self._make_decoded_type4(route_type=99),
+        )
+        assert result is not None
+        assert "route_type" not in result
+
+    def test_route_type_missing_omitted(self) -> None:
+        norm = self._make_normalizer()
+        result = norm._build_letsmesh_advertisement_payload(
+            {},
+            decoded_packet=self._make_decoded_type4(),
+        )
+        assert result is not None
+        assert "route_type" not in result
+
+    def test_advert_timestamp_extracted(self) -> None:
+        norm = self._make_normalizer()
+        result = norm._build_letsmesh_advertisement_payload(
+            {},
+            decoded_packet=self._make_decoded_type4(timestamp=1747300000),
+        )
+        assert result is not None
+        assert result["advert_timestamp"] == 1747300000
+
+    def test_advert_timestamp_missing_omitted(self) -> None:
+        norm = self._make_normalizer()
+        result = norm._build_letsmesh_advertisement_payload(
+            {},
+            decoded_packet=self._make_decoded_type4(),
+        )
+        assert result is not None
+        assert "advert_timestamp" not in result
+
+    def test_both_route_type_and_timestamp(self) -> None:
+        norm = self._make_normalizer()
+        result = norm._build_letsmesh_advertisement_payload(
+            {},
+            decoded_packet=self._make_decoded_type4(route_type=1, timestamp=1747300000),
+        )
+        assert result is not None
+        assert result["route_type"] == "flood"
+        assert result["advert_timestamp"] == 1747300000
+
+
 class TestMessageSnrCasing:
     """Tests for message payload SNR casing (lowercase output)."""
 
diff --git a/tests/test_common/test_hash_utils.py b/tests/test_common/test_hash_utils.py
index 62a85c2..7519bdd 100644
--- a/tests/test_common/test_hash_utils.py
+++ b/tests/test_common/test_hash_utils.py
@@ -264,3 +264,122 @@ class TestComputeTelemetryHash:
         )
 
         assert hash1 == hash2
+
+    def test_default_bucket_is_300s(self) -> None:
+        """Default bucket_seconds should be 300 (5 minutes)."""
+        time1 = datetime(2024, 1, 15, 10, 31, 0, tzinfo=timezone.utc)
+        time2 = datetime(2024, 1, 15, 10, 33, 0, tzinfo=timezone.utc)
+
+        hash1 = compute_telemetry_hash(
+            node_public_key="a" * 64,
+            parsed_data={"temp": 22.5},
+            received_at=time1,
+        )
+        hash2 = compute_telemetry_hash(
+            node_public_key="a" * 64,
+            parsed_data={"temp": 22.5},
+            received_at=time2,
+        )
+
+        assert hash1 == hash2
+
+
+class TestComputeAdvertisementHashWithAdvertTimestamp:
+    """Tests for compute_advertisement_hash with advert_timestamp parameter."""
+
+    def test_advert_timestamp_used_for_bucketing(self) -> None:
+        """When advert_timestamp is provided, it is used for time bucketing."""
+        received_at = datetime(2024, 1, 15, 10, 30, 0, tzinfo=timezone.utc)
+        advert_ts = datetime(2024, 1, 15, 10, 28, 0, tzinfo=timezone.utc)
+
+        hash_with_ts = compute_advertisement_hash(
+            public_key="a" * 64,
+            name="Node1",
+            received_at=received_at,
+            advert_timestamp=advert_ts,
+        )
+        hash_ts_only = compute_advertisement_hash(
+            public_key="a" * 64,
+            name="Node1",
+            received_at=received_at,
+            bucket_seconds=300,
+            advert_timestamp=advert_ts,
+        )
+
+        assert hash_with_ts == hash_ts_only
+
+    def test_advert_timestamp_overrides_received_at(self) -> None:
+        """advert_timestamp produces different bucket than received_at when far apart."""
+        received_at = datetime(2024, 1, 15, 10, 30, 0, tzinfo=timezone.utc)
+        advert_ts = datetime(2024, 1, 15, 12, 0, 0, tzinfo=timezone.utc)
+
+        hash_with_advert_ts = compute_advertisement_hash(
+            public_key="a" * 64,
+            name="Node1",
+            received_at=received_at,
+            advert_timestamp=advert_ts,
+        )
+        hash_with_received_at = compute_advertisement_hash(
+            public_key="a" * 64,
+            name="Node1",
+            received_at=received_at,
+        )
+
+        assert hash_with_advert_ts != hash_with_received_at
+
+    def test_same_advert_timestamp_same_hash(self) -> None:
+        """Same advert_timestamp but different received_at produces same hash."""
+        ts = datetime(2024, 1, 15, 10, 30, 0, tzinfo=timezone.utc)
+        recv1 = datetime(2024, 1, 15, 10, 31, 0, tzinfo=timezone.utc)
+        recv2 = datetime(2024, 1, 15, 10, 32, 0, tzinfo=timezone.utc)
+
+        hash1 = compute_advertisement_hash(
+            public_key="a" * 64,
+            name="Node1",
+            received_at=recv1,
+            advert_timestamp=ts,
+        )
+        hash2 = compute_advertisement_hash(
+            public_key="a" * 64,
+            name="Node1",
+            received_at=recv2,
+            advert_timestamp=ts,
+        )
+
+        assert hash1 == hash2
+
+    def test_none_advert_timestamp_falls_back_to_received_at(self) -> None:
+        """When advert_timestamp is None, received_at is used for bucketing."""
+        received_at = datetime(2024, 1, 15, 10, 30, 0, tzinfo=timezone.utc)
+
+        hash_explicit_none = compute_advertisement_hash(
+            public_key="a" * 64,
+            name="Node1",
+            received_at=received_at,
+            advert_timestamp=None,
+        )
+        hash_no_param = compute_advertisement_hash(
+            public_key="a" * 64,
+            name="Node1",
+            received_at=received_at,
+        )
+
+        assert hash_explicit_none == hash_no_param
+
+    def test_default_bucket_is_300s(self) -> None:
+        """Default bucket_seconds should be 300 (5 minutes)."""
+        time1 = datetime(2024, 1, 15, 10, 31, 0, tzinfo=timezone.utc)
+        time2 = datetime(2024, 1, 15, 10, 33, 0, tzinfo=timezone.utc)
+
+        hash1 = compute_advertisement_hash(
+            public_key="a" * 64,
+            name="Node1",
+            received_at=time1,
+        )
+        hash2 = compute_advertisement_hash(
+            public_key="a" * 64,
+            name="Node1",
+            received_at=time2,
+        )
+
+        assert hash1 == hash2
diff --git a/tests/test_common/test_i18n.py b/tests/test_common/test_i18n.py
index cb75cdd..863fac9 100644
--- a/tests/test_common/test_i18n.py
+++ b/tests/test_common/test_i18n.py
@@ -135,3 +135,20 @@ class TestEnJsonCompleteness:
         assert t("entities.messages") != "entities.messages"
         assert t("entities.map") != "entities.map"
         assert t("entities.members") != "entities.members"
+
+    def test_advertisements_route_type_keys(self):
+        """Advertisement route type filter keys are all present."""
+        assert (
+            t("advertisements.filter_route_type_label")
+            != "advertisements.filter_route_type_label"
+        )
+        assert t("advertisements.route_type_all") != "advertisements.route_type_all"
+        assert t("advertisements.route_type_flood") != "advertisements.route_type_flood"
+        assert (
+            t("advertisements.route_type_direct") != "advertisements.route_type_direct"
+        )
+        assert (
+            t("advertisements.route_type_unknown")
+            != "advertisements.route_type_unknown"
+        )
+        assert t("advertisements.col_route_type") != "advertisements.col_route_type"