diff --git a/backend/app/services/device_discovery.py b/backend/app/services/device_discovery.py
index f496fc9..58a51f6 100644
--- a/backend/app/services/device_discovery.py
+++ b/backend/app/services/device_discovery.py
@@ -479,6 +479,14 @@ async def discover_via_ssh(
         return result
 
     # Step 2: SSH into each rack, parse config, upsert devices
+    # Build mapping of external_id -> Rack ID for device assignment
+    rack_id_mapping = {}
+    from app.models.rack import Rack
+    all_racks = (await db.execute(select(Rack).where(Rack.object_id == obj.id))).scalars().all()
+    for rack in all_racks:
+        if rack.external_id:
+            rack_id_mapping[rack.external_id] = rack.id
+
     for external_id, rack_host, rack_name in rack_hosts:
         # Resolve config_path override from the embedded device's connection_params
         existing_rack_pc = (await db.execute(
@@ -563,8 +571,9 @@ async def discover_via_ssh(
         logger.info(f"[ssh_discovery] Found {len(devices_found)} devices from plugins in {rack_host}")
 
         for found in devices_found:
-            # Hostname: "rack{rack_name}-{plugin_name}", e.g. "rack01-camera_grz"
-            hostname = f"rack{rack_name}-{found.plugin_name}"
+            # Hostname: "{external_id}-{plugin_name}", e.g. "lane-1-1-camera_1"
+            hostname = f"{external_id}-{found.plugin_name}"
+            rack_id = rack_id_mapping.get(external_id)
 
             try:
                 existing = (await db.execute(
@@ -583,10 +592,14 @@ async def discover_via_ssh(
                         changes.append(f"role: other→{found.role}")
                         existing.role = found.role
                     # Update hostname if it was never set or still auto-generated
-                    if not existing.hostname or existing.hostname.startswith("rack"):
+                    if not existing.hostname or existing.hostname.startswith("rack") or existing.hostname.startswith("lane"):
                         if existing.hostname != hostname:
                             changes.append(f"hostname: '{existing.hostname}'→'{hostname}'")
                             existing.hostname = hostname
+                    # Update rack_id if not set
+                    if existing.rack_id is None and rack_id is not None:
+                        existing.rack_id = rack_id
+                        changes.append(f"rack_id: None→{rack_id}")
 
                     if changes:
                         logger.info(f"[ssh_discovery] {found.ip} ({found.plugin_name}) - UPDATED: {', '.join(changes)}")
@@ -618,9 +631,10 @@ async def discover_via_ssh(
                         category=found.category,
                         role=found.role,
                         source="auto_ssh",
+                        rack_id=rack_id,
                         device_meta={"plugin": found.plugin_name, "cls": found.cls},
                     ))
-                    logger.info(f"[ssh_discovery] {found.ip} ({found.plugin_name}) - ADDED: category={found.category}, role={found.role}, hostname={hostname}, source=auto_ssh")
+                    logger.info(f"[ssh_discovery] {found.ip} ({found.plugin_name}) - ADDED: category={found.category}, role={found.role}, hostname={hostname}, rack_id={rack_id}, source=auto_ssh")
                     result.created += 1
                     result.actions.append(DeviceAction(
                         ip=found.ip,