How to See Who’s on Your Wi-Fi
You can see who is using your Wi-Fi network through your router’s interface.
How to Lock Down Your Wi-Fi
If you discover unauthorized devices, change your Wi-Fi password to something much more secure, then encrypt network traffic with WPA or WPA2 encryption. The moment the router requires a new password that unauthorized users don’t know, they will be disconnected. As an added precaution, avoid weak passwords and change the network name (usually abbreviated as SSID), then disable SSID broadcast. Changing the password and SSID and suppressing SSID broadcast make the entire network appear to have gone offline to freeloading users.
More Advanced Router Security
Think of network security as a race to outrun a bear, You don’t need to be the fastest; you just need to be faster than the slowest person trying to escape. There’s no way to make a home network perfectly impervious to a dedicated hacker who has the tools and skills to break into your network. But if you layer enough security practices, the hacker will pluck the low-hanging fruit first, reducing your relative risk of intrusion. Start by implementing MAC address filtering on your router so that only the MAC addresses you specify (the ones that belong to your devices) are allowed to connect. This approach isn’t foolproof—it’s easy to spoof a MAC address—but this level of filtering adds one extra step to hack through and dissuades low-skill, opportunistic Wi-Fi leeches. Similarly, limit DHCP addresses to the exact number of devices you regularly use so that no new devices are allowed an IP address even if they manage to get past your Wi-Fi password. Most importantly: disable Wi-Fi Protected Setup. WPS allows one-touch pairing of a device to your router, but it’s notoriously insecure. WPS-enabled routers usually get hacked within a matter of minutes by following online tutorials that rely on easily available freeware.
Remain Vigilant
If you live in a rural area, you’re likely fine with just baseline precautions. To infiltrate your Wi-Fi network, a hacker must remain within Wi-Fi range, about 300 feet or so from the router. If your house is 500 feet from the road and your nearest neighbor is a quarter-mile away, an attacker would need to be on your property to hack your Wi-Fi. But if you live in a dense urban area or in proximity to others (e.g., in a dorm), the risk increases. Advanced technology to brute-force attack Wi-Fi routers has long been available as freely downloadable, open-source tools. Software like Reaver will slice through even strong defenses without much difficulty, so you must periodically check your router’s DCHP allocation tables to verify inappropriate access. Set a task on your calendar to-do list to periodically check your router’s control panel. Look for unauthorized devices. If you use strong security practices but your network is intruded upon repeatedly, reach out to your internet service provider for assistance. Persistent, successful intrusion against a well-protected home network is a sign of trouble that’s worth referring to your ISP.
