google pub dns no always pass ecs options to our authoritative dns

[Willian Wei]

hi, our authoritative DNS server support EDNS and half ECS(request with ECS will not rely with ECS options). For the same domain, we found sometimes google pub dns will send ECS options, and sometimes will not, is it caused by our authoritative server not reply with ECS options for the ECS reqeust?

[Alex Dupuy]

Willian wrote:

our authoritative DNS server support EDNS and half ECS(request with ECS will not rely with ECS options). For the same domain, we found sometimes google pub dns will send ECS options, and sometimes will not, is it caused by our authoritative server not reply with ECS options for the ECS request?

Yes, if you do not send ECS in a reply to a query with ECS, it is considered to show that you do not support ECS. This is generally true for all EDNS options, such as EDNS Cookies, Nameserver ID, etc.

See https://developers.google.com/speed/public-dns/docs/ecs for other reasons why Google Public DNS may not send you ECS.

[Willian Wei]

thanks, we add ECS in response, and now all google pub dns sent ECS to us.