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This article will explain in detail how to analyze client-side IPv6 and IPv4 parsing strategy changes. The content of the article is of high quality, so the editor will share it with you for reference. I hope you will have a certain understanding of the relevant knowledge after reading this article.

The details are as follows:

When AAAA record is set for sub-domain name branch line, but A record is not set, when recursive DNS requests A record, the resolution result is

Scene

Old strategy

New strategy

IPv4 client

No resolution

An A record that resolves to a low priority line, such as a default line

IPv6 client

Resolve to AAAA record

Resolve to AAAA record (no change)

Dual stack client

Resolve to AAAA record

Resolve to AAAA or A record, depending on the policy of the client and recursive DNS:

If you request AAAA records first, you will resolve to AAAA records, and if you request both AAAA and A records, you may resolve both.

1. Detailed description:

1) the old policy returns SOA records and does not return A records for low priority lines (such as default lines), which may cause some clients with pure IPv4 to fail to resolve.

2) the new policy will return the A record of the low priority line, such as setting the following record:

Www.a.com Foreign AAAA 11 Vol 11

Www.a.com default A 1.1.1.1

The old strategy can only resolve the AAAA record abroad, but not the A record; the foreign IPv4 environment of the new strategy can resolve to the A record of the default line.

2. If you need to keep the old strategy

If you still want to use the old policy and do not want the specified line to return the A record of the low priority line, you can set the specified line to the CNAME record in advance, and the domain name pointed to by the CNAME record can only set the AAAA record. Example:

Www.a.com default A 1.1.1.1

Www.a.com overseas CNAME v6.www.a.com

V6.www.a.com defaults to AAAA 11vvl 11

On how to analyze the client-side IPv6, IPv4 parsing strategy changes to share here, I hope the above content can be of some help to you, can learn more knowledge. If you think the article is good, you can share it for more people to see.

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