Slow internet connection after MAC address spoof

I'd like to ask a question about spoofing MAC addresses. I'm trying it out in my own wifi network just to see how it's done. I'm running ubuntu 16.04 LTS. Let's say my original MAC address is 00:22:ac:55:0b:02. Using ifconfig I do: sudo ifconfig wlan0 down sudo ifconfig wlan0 hw ether 00:22:ac:55:0b:01 sudo ifconfig wlan0 up As you can see, I've only changed the last digit of my MAC address. If I now try to load a web page (in Firefox), I get a "server not found" error. After calling sudo dhclient wlan0 I am able to load web pages but only very slowly. About half the time I still get the same "server not found error" as well, but by hitting f5 repeatedly it sometimes works. If I go back to my original MAC address, the first three commands are enough to get me connected, and I don't always even need to call dhclient. Needless to say, the internet is nice and fast with my original configuration. I'm curious about why, after spoofing my MAC address, I get a trickle of slow internet connection. I would have thought I would either have the same connection as before, or not be connected at all. Could someone wiser than me explain? Cheers