If dns gets taken out or filtered it would be a good idea to collect the IP addresses of the sites you like to use.
From their learn how to update your local host file on whatever OS you use.
Have it ready to go in the event of a DNS outage and you can't resolve anything from your PC. If you create a localhost file you can populate it with the IPs and DNS. Your system will always look there first for "directions" to find your favorite sites. Im sure many anons have already stared building these. If not maybe we should build one this evening