I am not able to get my MacBook Air to resolve any hosts.
I've tried reinstalling Yosemite from recovery, unloading and reloading the mDNSResponder to no avail. An nslookup of www.google.com using 22.214.171.124 resolves correctly. I've tried different WiFi networks and disabling and re-enabling the WiFi. I don't know what else to try. I did an ifconfig and it did not show any name severs