GitHub Pages DNS check keeps failing for peaksel.az despite correct DNS responses

[pikseliok]

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Hello,

I’m trying to connect my custom domain, peaksel.az, to my GitHub Pages site, but GitHub Pages continues to report a DNS error. I have been troubleshooting this for two days and have repeatedly checked the DNS records and Pages settings. The same error persists.

Repository: https://github.com/pikseliok/piksel.iokk
GitHub Pages domain: pikseliok.github.io
Custom domain in Pages settings: peaksel.az
Alternate name: www.peaksel.az
DNS provider: Cloudflare

The exact error shown in Repository → Settings → Pages is:

Both peaksel.az and its alternate name are improperly configured
Domain's DNS record could not be retrieved.
(InvalidDNSError)

Here is what I have checked:

A records for the apex domain

Cloudflare’s authoritative nameserver, cheryl.ns.cloudflare.com, returns all four GitHub Pages IPv4 addresses for peaksel.az:

185.199.108.153

185.199.109.153

185.199.110.153

185.199.111.153

I also queried Google DNS (8.8.8.8), which returned the same four addresses.

CNAME for the www alternate name

The authoritative Cloudflare nameserver returns:

www.peaksel.az CNAME pikseliok.github.io

Google DNS resolves www.peaksel.az through that CNAME to the same four GitHub Pages IPv4 addresses.

Nameservers and Cloudflare proxy

The domain’s nameservers resolve to Cloudflare:

cheryl.ns.cloudflare.com

jaxson.ns.cloudflare.com

The GitHub Pages records are set to DNS only in Cloudflare, with the proxy disabled.

IPv6 and DNSSEC checks

An AAAA query for peaksel.az returned no AAAA record. A DS query returned the .az zone’s SOA in the authority section and no DS record for peaksel.az.

Pages settings and retry

I removed peaksel.az from the repository’s Pages settings and added it again to trigger a fresh DNS check. GitHub briefly showed “DNS check is in progress,” but the check then returned the same InvalidDNSError. I have repeated the relevant checks over the last two days and continue to get the same result.

The DNS responses I receive from Cloudflare’s authoritative nameserver and Google DNS match the GitHub Pages configuration I expect. Could someone help identify why GitHub Pages cannot retrieve or validate the domain’s DNS records? Is there another DNS record or Pages setting I should check, or could the domain validation be stuck on GitHub’s side?

I can provide the exact PowerShell query outputs and a screenshot of the Pages error if needed.

Thank you.

[SontuCoder]

Hi my Friend,

The reported DNS records appear consistent with the standard GitHub Pages configuration, so the cause cannot be established from the post alone.
Check the domain's CAA records for certificate restrictions, ensure Cloudflare's proxy remains disabled during troubleshooting, and test the authoritative nameservers independently. If records remain consistent across resolvers and GitHub still fails validation, contact GitHub Support with the DNS query results and repository details.
Avoid repeatedly changing already-correct records without identifying the actual failure.

[KasraK2K]

Hi @pikseliok,

I understand your frustration. After analyzing your setup, I believe I've identified the likely issue. Here's what's happening and how to fix it:

The Problem

While your DNS records appear correct when queried directly, GitHub Pages likely cannot reach your authoritative nameserver or there's a network/connectivity issue on GitHub's side when they perform their validation. This is particularly common with the .az TLD.

Key Issue: Nameserver Connectivity

The most common cause of InvalidDNSError despite correct DNS records is:

• GitHub's DNS validation server cannot reach or communicate with your authoritative nameservers (cheryl.ns.cloudflare.com, jaxson.ns.cloudflare.com)
• • Some ISPs, firewalls, or network configurations block or rate-limit DNS queries from external validators
• • The .az domain extension may have specific DNS validation requirements

Recommended Solutions (in order)

1. Check CAA Records (Most likely culprit)

Ensure your domain doesn't have restrictive CAA records. Run:

nslookup -type=CAA peaksel.az

If you see CAA records that don't include GitHub or Let's Encrypt, add:

0 issue "letsencrypt.org"
0 issuewild "letsencrypt.org"
0 issue "github.com"

2. Verify Nameserver Propagation

Even though you've checked, try verifying from a different DNS perspective:

dig NS peaksel.az @8.8.8.8
dig A peaksel.az @cheryl.ns.cloudflare.com +short

3. Try ALIAS/ANAME Record (Alternative approach)

Instead of A records, if your DNS provider supports it, use:

• ALIAS or ANAME record pointing to pikseliok.github.io for the apex domain
• • Keep the CNAME for www subdomain as-is

4. Wait and Retry

Sometimes GitHub's validation has temporary issues. Wait 24 hours, then:

• Remove the domain from Pages settings
• • Clear browser cache
• • Re-add the domain

5. Contact GitHub Support

If steps 1-4 don't work, contact GitHub Support with:

• Your DNS query outputs
• • Repository URL
• • The exact error message screenshot
• • Confirmation that you're using Cloudflare with DNS only (no proxy)
    They can check their server-side logs to see if they're even reaching your nameservers.

Important Notes

• Ensure Cloudflare proxy is OFF (DNS only) during the entire troubleshooting process
• • The IPv4 A records you have are correct
• • DNSSEC is not required for GitHub Pages (your lack of DS record is fine)
• • AAAA records are optional
    The fact that external DNS queries work perfectly means your configuration is correct—this is a GitHub-side validation issue, most likely nameserver accessibility or CAA record restrictions.

Give the CAA records check priority, and let me know if that resolves it!