Every once in a while (it doesn’t happen very often) DNS servers would stop resolving certain domains causing intermittent issues when accessing the Internet. To solve the DNS issues, I often switch DNS servers on my main router. Changing DNS servers may require rebooting your router.
So, here’s a list of DNS servers you could use on your router, in case the current DNS servers you are using is having problems. I primarily use OpenDNS and Google DNS servers, but others DNS servers are reliable as well.
OpenDNS
208.67.222.222 Primary
208.67.220.220 Secondary
8.8.8.8 Primary
8.8.4.4 Secondary
Comcast
75.75.75.75 Primary
75.75.76.76 Secondary
AT&T DSL
68.94.156.1 Primary
68.94.157.1 Secondary
UltraDNS
156.154.70.1 Primary
156.154.71.1 Secondary
ScrubIt
67.138.54.100 Primary
207.225.209.66 Secondary
DNSResolvers
205.210.42.205 Primary
64.68.200.200 Secondary