I've only got a basic idea about networking, Google is my teacher.
- Router: Tenda D303
- Location: India
- Connection: BSNL Unlimited 1Mbps broadband.
Friends and relatives visit me often, and connect to my Wi-Fi while they're here, just for WhatsApp or emails, and nothing heavy. I tell them the WiFi password; WPS is disabled. Only I know the password to the router management page.
Since the last week or so, the connection has been very slow in my house.
- At least 30 devices were seen in the DHCP table, even though almost 25 of them weren't in my place at the time. So I changed the DHCP lease time from the default 24 hours to 3. Speeds didn't improve.
- Even with the 3-hour lease times, at late nights I notice at least 5 or more MAC addresses titled "DELL" connected, even though there are only two DELL laptops in my home.
- Changed the Wi-Fi password twice, still see the strange "DELL"s in the list at nights.
- Googled the MAC addresses, couldn't find any reliable info about them.
- Used MAC filtering to ban 5 of these odd "DELL" addresses. They're still in the list.
Also, tried resetting, rebooting all the concerned devices, and the router at home. No improvement whatsoever.
I fear that these 5 odd MAC addresses are the cause for slow internet. What can be done?