/etc/network/interfaces I have multiple servers listed on
dns-nameservers, one set of ubuntu servers has 3, another 4. We had no issues until we were forced to add yet 2 more to each, but we still could not successfully resolve using the new DNS servers. After some investigation, we found that only 3 DNS servers were copied into
/etc/resolv.conf. We are able to resolve our immediate issue by putting the 3 primary servers in there and omitting the backup DNS servers, but I’d like to get keep all necessary DNS servers available.
As for why so many:
- 18.104.22.168 is used because it gets updated information faster than our internal ones
- Our internal network DNS
- Another DNS for a DB cluster