I noticed during several installs of 7.1-RELEASE (i386 and AMD64) if you say "no" to "Do you want to try to configure IPV6" then your IPV4 stuff will not work and you have to manually configure it which is a PITA the first few dozen times until you remember what you did on your old/missing system.
If you say "yes" to IPV6 then the installer sets up DHCP and everything's fine.
If you say "yes" to IPV6 then the installer sets up DHCP and everything's fine.