They aren't assigned to any individual vendor by the IEEE. Those 5 MAC addresses all are in the 00:FF domain, which are traditionally used for bridged/routed adapters. I even checked all my other devices’ MAC addresses.

My 2 DELL laptops appear separately with their own MAC addresses starting with 9c:2a and 64:5a respectively. I “banned” these 5 under router’s MAC filter, yet they pass through.My research shows a clear correlation between slow internet and presence of these 5.These 5 MAC addresses, all starting with 00:ff, and titled “DELL” in the DHCP table is what troubles me. Now let's set aside the slow internet issue. Highly unlikely because when I disable Wi-Fi and use internet via Ethernet from the same router, all works fine, on all PCs. “Malware or user-installed software like bittorrent using up bandwidth.”Ĭouldn’t find any malware on any of my devices, nor any heavy downloading.Also, not many wireless equipment here that could cause interference. I couldn’t find any visible Wi-Fi access points or a router other than mine in my home and vicinity. It’s more like a countryside, more greenery, and less routers in here. “Interference from neighbours’ routers.”.There are no neighbours other than some close family members, and I have discussed with them this issue. Tried several complex passphrases for a month now. I’ve been using WPA2-PSK authentication, with AES encryption.

“Possibly weak passphrase for Wi-Fi, hence neighbours using it.”.

User drjimbob helped to eliminate other possible causes for slow internet, and here’s my research: Router: Tenda D303, Location: India, Connection: BSNL Unlimited 1Mbps broadband. Previously, I mentioned 5 unknown MAC addresses often connecting to my router, and noticeably causes my internet to be slow.

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