Verify that the radio button next to Use the Following IP Address is selected, and that the IP address, subnet mask, and default gateway are configured. Click on Advanced and select the DNS tab. Use the Add button to add a server to the DNS search order. To remove a server from the list, select the IP address of the server and click on Remove.
To change the order of the DNS servers that are listed, select the IP address of a server and click on the Up or Down arrows—DNS servers are queried from top to bottom in the order that they are listed. The following example adds a new DNS server, To configure the DNS servers for a network interface card, configure the following Registry value. Since DNS queries are sent to each server in the order that they're listed, configuring the DNS search order correctly can optimize name resolution performance.
When requesting a DNS lookup, the client computer in this case, a Windows Server computer will send a query to the first server listed in the DNS search order. If the first server does not respond after a specific amount of time 5 seconds by default , the computer will send the query to the second server in the search order, and so on.
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Let's say I have several interfaces, all active, some with no dns server specified, some told to determine it automatically, and some with it specified manually in interface ipv4 AND interface ipv6. I'm asking for an answer to this general question hoping that I know how to solve a more specific problem in Windows Vista - I have two interfaces, one a lower metric and a DNS server specified manually.
However, all other applications fail to resolve the name unless I manually specify a DNS server for the other interface, which the applications then use. If I'm not mistaken, it's determined by the NIC binding order in the Advanced Settings in the network connections folder. You can verify it by changing the binding order of the various NIC's and running nslookup as a test. To expand on my answer, citing the article that Evan linked , here is an excerpt from said article:. If the DNS Client service does not receive a response from the first DNS server within one second, it sends the name query to the first DNS servers on all adapters that are still under consideration and waits two seconds for a response.
If the DNS Client service still does not receive a response from any DNS server, it sends the name query to all DNS servers on all adapters that are still under consideration and waits four seconds for a response. I suspect this works because part of the route selection is to then set the source IP of the interface with the highest metric priority lowest number as you are not using the same IP address for all connections, whereas a dual-homed BGP connection would use the same source IP, but select different next-hop gateways pending destination IP.
To specifically answer the question, Windows uses the first DNS records associated with the highest ranking network interface an InterfaceMetric with a lower value has higher rank. Examples below show how to obtain and change that interface ranking value. A common scenario where this issue pops up is when you have one or more VPNs that provide a DNS server for resources defined for that virtual network.
However, the public DNS server assigned by a WiFi router is taking precedent and either claiming that hosts don't exist or are responding with the unexpected IP address. To resolve this, we need to explicitly dictate which network interface should take precedence by specifying its associated "metric".
Currently, this metric appears to only be settable via PowerShell This page describes the algorithm used by Windows to perform DNS queries. If you have several network cards and if you specify a DNS server in each of them do you know what DNS server will be used? The answer from qwerty is right and correct. As this might help you or others, you can disable the windows round-robin usage of the listed dns to make the dns usage more predictable.
There is also a "timeout" for rotating the servers, you can also try to setting it to zero :. It doesn't decide randomly. Or perhaps you decide on having your own DNS servers. That works too. Just enter the IP adresses in the network center and all should be well. And yes, you'll have to set those manually. To a local server which must be running and listening to port Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group.
If that fails - I would want to know right away - so I can fix it - or just point unbound to different NS or just let it resolve if my filtering is down. Vs a scenario where my filtering is not working and I don't know about it, they you have say a kid looking at porn, or infecting your network with malware.. How exactly does unbound flip to this other NS - 1 query fails, 10, what if one query just takes a long time? When does it fail back - does it not? So no you run into a scenario where again you do not know what is being asked - your filter system, or not filtered.
Which is a horrible scenario.. The only time you should switch to non filtered, is your sure - I you actually tested, yup if broke - and I can not fix it in 2 minutes. So flip users over to nonfiltered in 10 seconds.
There is no way to do your "only" if scenario that makes any sense - if your worried about your filtering system fail - then make sure it doesnt.. That is where time spent on what happens if fail mode should be concentrated.. Register Login. Reply Reply as topic. This topic has been deleted.
Only users with topic management privileges can see it. Yes, quite. You don't! Why anyone thinks they should be asked in order? If you want forwarding done sequentially to specific dns - then use the forwarder.. That unbound even has a forwarding mode is pretty stupid if you ask me - its a Resolver ; In what possible scenario in dns does it make sense to have to ask specific dns in order? So in what scenario does it matter which dns you ask first? So your security matters when its available - but hey if not then just send my shit to any dns that will resolve it give me an IP I can go too ; Do you not see the problem with that logic??
From a security point of view? If they are all secure then what does it matter what order you ask them ; Or you could just freaking RESOLVE, using dnssec - and not give 2 shits if comodo or google or open or isp dns is down..
Andrew : Does that mean that somewhere you still need to tell DNS Resolver what root server to use? Thanks johnpoz. Always grateful for your help. Thanks for everyone's help. Hi all, I want to come back to this topic. If your concerned with where your running your filtering failing - that make sure if 1 ns fails there is another that does the same filtering If that fails - I would want to know right away - so I can fix it - or just point unbound to different NS or just let it resolve if my filtering is down.
First post.
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