My Telus Internet connection loses DNS configuration every once in a while. Over a 3 month period, it used to fail DNS resolution perhaps once a month or less. This week though, it has happened 4 times already. This happens across the board on all devices. I repeat it only loses the DNS resolution part. My work VPN connections, on going Netflix connection all stay on without any issues. I do not use Telus' name servers; I have disabled IPV6. The modem/router is standard cylindrical Telus WifiHub.
Wifi connection is good, connection from modem to Telus is good. When I used nslookup from the command prompt to point to 126.96.36.199, 188.8.131.52, the openDNS name servers, they all answer my DNS queries. However when you try to ping, say, google.com or telus.com, or connect to them from a browser, it fails to resolve the names. Rebooting the modem restores DNS resolution but I cannot and don't want to reboot the
Telus techsupport has been very helpful but have not been able to resolve the issue, other than rebooting the modem and suggesting to reset it. Please let me know if there is a way to fix this issue.
A couple things to try in the CLI if you haven't...
If Windows: try 'ipconfig /all | more' .. this lets you page through the network settings and will show your system dns severs, which may be different than the ones you are testing with.
Another thing to try in the windows CLI is 'ipconfig /flushdns' which clears out the DNS cache... this sometimes resolves similar issues but doesn't always help.
In unix like environements, DNS servers are usually specified in the '/etc/resolv.conf' file which is typically managed by other system processes (DHCP clients or netplan etc). The 'dig' command is useful for troubleshooting DNS issues.
For my personal set up, I configured my gateway router to act as a cacheing DNS server which forwards requests to a bunch of public DNSs like 184.108.40.206 etc. Everything inside uses the gateway as their DNS server (with 220.127.116.11 as secondary, just in case :-). My windows desktop gets confused once in a while when I mess with network or servers but everythiing else seems okay..
I have the exact same problem. It seems to be a software issue with the Telus modem. Seems to be a problem with the DNS resolver on the box. The silly thing is you can't override the DNS servers provided by the DHCP server on the modem. The setting seems to be there (although it only lets you enter one server) but the client will always receive the gateway address of the router.