ISP Device Tracking: What They Can See

TL;DR

Your ISP can detect devices connected to their router, but the level of detail varies. They generally see basic information like MAC addresses and IP addresses assigned, but not necessarily what you’re doing with those devices. Logging practices differ between ISPs.

Understanding What Your ISP Sees

When you connect a device to your home network using an ISP-provided router, several pieces of information become visible to the ISP. Here’s a breakdown:

1. Basic Device Identification

• MAC Address: This is a unique identifier for your device’s network interface card (NIC). The router records which MAC addresses connect to it.
• IP Address: Your ISP assigns an IP address to the router, and the router then assigns local IP addresses to devices on your home network. The ISP sees these assigned IPs.
• Connection Time/Duration: They can see when a device connects and disconnects from the network.

These details allow them to track a device, but not necessarily identify you using it without further information.

2. What ISPs Generally *Can’t* See

• Website History: Most ISPs don’t actively log every website you visit anymore due to privacy concerns and net neutrality regulations. However, they can see the domains you connect to (e.g., google.com) but not necessarily the specific pages within those domains.
• Data Content: They cannot see the actual content of your encrypted web traffic (HTTPS).
• Application Usage: They generally can’t tell which apps you’re using, unless that app uses unencrypted connections.

3. How ISPs Log Device Information

1. Router Logs: ISP-provided routers often keep logs of connected devices, their IP addresses, and connection times. These logs are stored on the router itself or sent back to the ISP’s servers.
2. Deep Packet Inspection (DPI): Some ISPs use DPI technology to examine network traffic for specific patterns. While they can’t see content, they might identify certain applications or services being used. This is less common due to privacy implications.
3. Network Monitoring: ISPs monitor overall network performance and may collect data about bandwidth usage per IP address.

4. Checking Your Router’s Logs (If Possible)

Accessing router logs depends on the router model. Here’s a general approach:

1. Find your Router’s IP Address: Open Command Prompt (Windows) or Terminal (macOS/Linux) and type ipconfig (Windows) or ifconfig (macOS/Linux). Look for the “Default Gateway” address.
2. Access the Router Interface: Type the Default Gateway IP address into a web browser. You’ll be prompted for a username and password (often found on a sticker on the router itself, or in your ISP’s documentation).
3. Locate Logs: Once logged in, look for sections like “Logs,” “System Logs,” or “Connection Logs.” The exact location varies by manufacturer.

Important Note: Many ISPs lock down access to router logs on their provided equipment to prevent users from investigating.

5. Protecting Your Privacy

• Use a VPN: A Virtual Private Network encrypts your internet traffic and hides your IP address, making it harder for the ISP to track your online activity.
• Use HTTPS Everywhere: Ensure websites use HTTPS (look for the padlock icon in your browser) to encrypt data transmission.
• Change Router Password: Change the default router password to prevent unauthorized access and potential log manipulation.
• Consider a Personal Router: Using your own router gives you more control over settings, logging, and security features.