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Microsoft DNS

From here.

PowerShell DNS

Get-DnsClientServerAddress | Select-Object -ExpandProperty ServerAddresses

DDNS

If clients are doing DDNS:

  • Windows clients update their DNS name once a day.
  • Windows domain controllers update their DNS name once an hour.

Supported Features in 2022

List of new DNS features from Microsoft.

  • Application Load Balancing. When you have deployed multiple instances of an application at different locations, you can use DNS policy to balance the traffic load between the different application instances, dynamically allocating the traffic load for the application.
  • Geo-Location Based Traffic Management. You can use DNS Policy to allow primary and secondary DNS servers to respond to DNS client queries based on the geographical location of both the client and the resource to which the client is attempting to connect, providing the client with the IP address of the closest resource.
  • Split Brain DNS. With split-brain DNS, DNS records are split into different Zone Scopes on the same DNS server, and DNS clients receive a response based on whether the clients are internal or external clients. You can configure split-brain DNS for Active Directory integrated zones or for zones on standalone DNS servers.
  • Filtering. You can configure DNS policy to create query filters that are based on criteria that you supply. Query filters in DNS policy allow you to configure the DNS server to respond in a custom manner based on the DNS query and DNS client that sends the DNS query.
  • Forensics. You can use DNS policy to redirect malicious DNS clients to a non-existent IP address instead of directing them to the computer they are trying to reach.
  • Time of day based redirection. You can use DNS policy to distribute application traffic across different geographically distributed instances of an application by using DNS policies that are based on the time of day.

NCSI active probes and the network status alert

The active probe process consists of the following steps:

Windows 10 or later versions

  • NCSI sends a DNS request to resolve the address of the www.msftconnecttest.com FQDN.
  • If NCSI receives a valid response from a DNS server, NCSI sends a plain HTTP GET request to http://www.msftconnecttest.com/connecttest.txt.
  • If NCSI successfully downloads the text file, it makes sure that the file contains Microsoft Connect Test.
  • NCSI sends another DNS request to resolve the address of the dns.msftncsi.com FQDN.

If any of these requests fails, the network alert appears in the Task Bar (as described in Symptoms). If you hover over the icon, you see a message such as “No connectivity” or “Limited Internet access” (depending on which requests failed).

If all of these requests succeed, the Task Bar shows the usual network icon. If you hover over the icon, you see a message such as “Internet access.”

Windows 8.1 or earlier versions

  • NCSI sends a DNS request to resolve the address of the www.msftncsi.com FQDN.
  • If NCSI receives a valid response from a DNS server, NCSI sends a plain HTTP GET request to http://www.msftncsi.com/ncsi.txt.
  • If NCSI successfully downloads the text file, it makes sure that the file contains Microsoft NCSI.
  • NCSI sends another DNS request to resolve the address of the dns.msftncsi.com FQDN.

If any of these requests fails, the network alert appears in the Task Bar (as described in Symptoms). If you hover over the icon, you see a message such as “No connectivity” or “Limited Internet access” (depending on which requests failed).

If all of these requests succeed, the Task Bar shows the usual network icon. If you hover over the icon, you see a message such as “Internet access.”

dns/microsoft.1719834037.txt.gz · Last modified: by bstafford