AD DNS forwarders and EDNS0 with ECS options

Question

Does Windows DNS Server understand ECS options of EDNS0 (RFC 7871)? (server 2016 and newer)
Will Windows DNS Server forward ECS Information from EDNS0 queries?

Answer 1

@BriggsDane Hi,

Thank you for posting in Q&A!

This question have been discussed before many times. However, unfortunately it doesn't exist any MSFT official Documentation about this question.

According to one user's description:

What we're finding is that we can send requests to the DNS servers that include the EDNS Client Subnet option, but they appear to be dropping it when they (the Windows DNS Server) forward the request to the load-balancers. All of the DNS Servers are 2012 R2. Packet capture shows the request hitting the server including the request, then when the server forwards it to the load-balancer, the option is no longer there.
https://www.reddit.com/r/dns/comments/eyjkth/windows_server_dns_edns_client_subnet_option/?sort=confidence

We have reported this question to the official document team. And they will post the newest documents about windows server&ECS options of EDNS0 in the near future. Thank you for your understanding!

Hope you have a nice day : )
Gloria

============================================

If the Answer is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.
https://learn.microsoft.com/en-us/answers/articles/67444/email-notifications.html