Wondering what "connected" actually means?

When it comes to determining whether a device is "connected" on a network, it typically refers to the device being actively connected and communicating with the network infrastructure. However, the exact definition and criteria for determining connectivity can vary depending on the specific network equipment and protocols being used.

In most cases, devices are considered connected when they meet the following conditions:

1. IP Address Assignment: The device has obtained an IP address either through DHCP (Dynamic Host Configuration Protocol) or has a static IP address assigned to it.

2. Network Reachability: The device can communicate with other devices on the network. This can be verified through various network protocols like ARP (Address Resolution Protocol) or NDP (Neighbor Discovery Protocol) for IPv6.

3. Link Status: The device is physically connected to the network and the link is active. This applies to both wired and wireless connections. For wired connections, it typically means the Ethernet link is up, and for wireless connections, it means the device is connected to the Wi-Fi network and has a strong signal.

4. Keep-Alive Mechanisms: Some devices implement keep-alive mechanisms, such as sending periodic packets or heartbeat messages, to signal their presence and maintain their connection status. However, not all devices or network equipment support or rely on such mechanisms.

It's worth noting that different routers and network monitoring tools may use different methods to determine device connectivity. Some may rely solely on DHCP lease information, while others may perform active probing or monitoring to check the responsiveness of devices.

In the case of the devices you mentioned, there could be various factors at play. Battery-operated devices like Schlage door locks and devices in power-saving mode like the Apple Watch may temporarily disconnect from the network to conserve power and re-establish their connection when needed. It's also possible that the router's monitoring interface may have limitations or delays in updating the connected device list.

To get more detailed insights into device connectivity and behavior, you can consider using network monitoring tools or scripts, like the one you mentioned, to track and monitor device status, network traffic, and any anomalies. These tools can provide more information about device connections, uptime, and performance metrics to help troubleshoot connectivity issues or identify patterns in device behavior.

Ultimately, the concept of "connected" devices is multifaceted and can depend on various factors, including network protocols, device capabilities, and monitoring mechanisms.

Regards;

David Johnson.