How does EDNS Client Subnet work?

How does EDNS Client Subnet work?

EDNS Client Subnet (ECS) is a mechanism for the desired source IP address of a DNS query to be embedded within the EDNS information of a DNS packet. The authoritative DNS server supporting ECS will read this source information and answer with the A record of the best located server possible.

What is extended Client Subnet?

From Wikipedia, the free encyclopedia. EDNS Client Subnet (ECS) is an option in the Extension Mechanisms for DNS that allows a recursive DNS resolver to specify the subnetwork for the host or client on whose behalf it is making a DNS query.

What is EDNS0 Client Subnet?

ECS is an optional extension to the DNS protocol, published in RFC7871. It allows DNS requests to contain information about the source of the request, and for responses to provide information regarding for whom responses can be cached.

What is OpenDNS ECS?

The OpenDNS feature provides DNS-based security policies to secure the subscriber traffic based on the policy associated with it. StarOS already supports readdressing of DNS traffic to the specific DNS server. Configuration for readdressing of DNS traffic is available in the charging action of the ECS service.

What does EDNS stand for?

Extension Mechanisms for DNS (EDNS) is a specification for expanding the size of several parameters of the Domain Name System (DNS) protocol which had size restrictions that the Internet engineering community deemed too limited for increasing functionality of the protocol.

How do you check if EDNS is supported?

How can I determine if my public DNS resolver supports the EDNS Client Subnet (ECS) extension?

1. Use the “edns-client-sub.net” TXT record set:
2. Use the “o-o.myaddr.l.google.com” TXT record set:
3. Use the “resolver-identity.cloudfront.net” record set.
4. Use the “rs.dns-oarc.net” TXT record set.

How do you check if Edns is supported?

Does Cloudflare support Edns?

1.1. 1.1 is a privacy centric resolver so it does not send any client IP information and does not send the EDNS Client Subnet Header to authoritative servers.

What does Edns stand for?

Does OpenDNS support EDNS?

OpenDNS has supported EDNS for a very long time, and in fact, relies heavily on EDNS to communicate identity and apply policy. Like most major recursive DNS providers, we have also implemented workarounds for retrying DNS queries without EDNS if an authority failed to properly respond to a query sent with EDNS enabled.

What is Edns compliance?

EDNS, short for Extension Mechanisms for DNS, is defined in RFC 6891 an extension to the DNS protocol, for the exchange of information between clients (resolvers) and servers. An EDNS-compliant server is therefore one that supports the EDNS extension or is capable of ignoring it in accordance with the specification.

Does Cloudflare use ECS?

The trend those days for newer, privacy oriented public DNS resolver seems to be ditching ECS altogether. This is the choice Cloudflare DNS and Quad9 have made for instance. Their reasoning is that with the many locations they have, their cache is sufficiently localized to offset the absence of ECS.