Originally Posted by OVERKILL
Originally Posted by ZeeOSix
Note - the Ethernet NIC in my computer is set to "Obtain DNS server address automatically". I'm confused on if the modem or the Ethernet NIC is controlling what DNS is used? The NIC goes into the modem with an Ethernet cable, is the DNS controlled by the NIC just for the computer, and the DNS in the modem is used only for the devices using it vis WiFi?
There are two different settings for DNS that you are kind of conflating here:
1. The DNS servers used by your modem itself when it gets an IP address from your ISP
2. The DNS servers assigned to DHCP clients on your LAN
These can be entirely separate. The default config typically uses the DNS servers provided by the ISP and either acts as a DNS proxy where the modem acts as the DNS server for the LAN, OR, it will pass on the DNS server addresses it received to the clients. You can check how DNS for clients is configured in the LAN DHCP settings usually.
Yes, I am confused on how the DNS settings on two pieces of hardware in the network (NIC in computer and the Modem/Router) behave, and which one controls what.
Originally Posted by OVERKILL
Originally Posted by ZeeOSix
My internet seems to work fine and has the advertised speed, so not sure if the DNS diagnostic test "Fails" are actually impacting anything. I don't like seeing "Failed" when diagnostic tests are ran, and want to find out why it's showing "Failed".
As I noted earlier, IF you can change them to the OpenDNS servers, I'd do that. My results are the same as yours and Skippy's, your secondary DNS server doesn't appear to respond to ICMP traffic (ping).
I did some searching last night and found a couple of threads on the OpenDNS chat board on how to setup my modem/router to use OpenDNS. I haven't tired it yet, as I'm wondering if it would actually give me any better performance or other benefits. My internet seems to work just fine at this point without any obvious indications that it has performance problems, except maybe something related to the DNS "Failed" diagnostics test (see below for my theory on that). I even ran the DOS command that was given in the OpenDNS chat board thread to see if my IP redirects my DNS queries. Output says I can use OpenDNS.
I think the modem self diagnostic test "fails" for my DNS #1 (205.171.3.25) and DNS #2 (205.171.2.25) is because the self diagnostic test probably sees ping time outs, just like we do when pinging it in DOS. Like mentioned earlier, DNS #1 would pass sometimes and DNS #2 fail all the time in the self diagnostic test, pretty much mirroring what myself, you and Skippy722 see when pinging those DNSs in DOS. Maybe CenturyLink has issues with their servers and will see that and get then working right - ?.
I might give it a week and do some more diagnostic and ping tests to see if DNS #1 and DNS #2 ping out better than they do now. If those DNSs have ping issues, how come I don't see any obvious indication of their bad performance on my end?