chilinux wrote
In addition to 8.8.8.8 as the Primary, I recommend using 8.8.4.4 as the Secondary.
Actually that does not matter. Both addresses are anycast, so your queries are answered by any member of the Google Public DNS farm. Probably all the members of the farm are answering on both addresses.
There is nothing wrong with only using only one of those addresses for DNS. The only way it can be a SPOF is when a firewall blocks the address (and if it blocks one, most likely it blocks the other.)
regards, rob0