Common DNS and Subdomain Issues: The Complete Troubleshooting Guide

Configuring custom DNS records and deploying applications to modern cloud providers is usually seamless, but subtle browser quirks, DNS caching, and strict provider validation rules can occasionally cause unexpected confusion. Here are clear, step-by-step solutions for the most common issues developers run into when managing free subdomains.

1. "Why is the Default Favicon Still Showing on My Website?"

The Problem: You pointed your subdomain to Vercel, Netlify, or your VPS, and your website HTML loads correctly, but the browser tab persistently shows the default green surfboard favicon instead of your project's custom icon.

The Cause: Web browsers (especially Google Chrome and Apple Safari) cache favicons aggressively and independently of normal HTML/CSS cache. When you first visited your subdomain immediately after claiming it, your browser cached the default parked page's favicon. Even when your new app is deployed, the browser continues reading the favicon from its internal SQLite favicon database.

2. How to Replace the Default "Parked" CNAME Record

The Problem: When you first register a subdomain, you see an initial default record pointing to the parked domain target. When you try to connect GitHub Pages or Vercel, you might wonder whether to edit or delete it.

The Solution: Every newly registered subdomain starts in a "parked" state so visitors see a clean placeholder until you are ready to deploy. To point the domain to your own server:

1. Navigate to your Dashboard → Manage DNS.
2. Click Delete on the initial default apex (@) CNAME record, or simply click Edit.
3. Add your desired target (e.g. cname.vercel-dns.com or your server IP address).
4. Click Save. Our Anycast DNS replaces the parked record instantly across all global nameservers.

3. Verification TXT Records: What Formats Are Supported?

The Problem: You need to verify ownership of your domain with a third-party platform (such as Vercel, Cloudflare, OpenAI Sites, Google Search Console, or Microsoft 365), but you are unsure which TXT record formats are valid.

The Solution: To prevent DNS abuse, Devs.Surf allows standard hosting and verification TXT patterns. Common verification records include:

Tip: When copying values from your hosting dashboard, make sure there are no accidental trailing spaces or unescaped quotes in the content field.

4. "Can I Delegate Nameservers (NS Records) for My Subdomain?"

The Question: Can I change the NS records to point my subdomain directly to Vercel DNS or Cloudflare DNS nameservers?

The Technical Reality: Subdomains under a shared zone (like .devs.surf) cannot have NS delegation assigned to individual third-party name servers, because nameserver delegation splits the root zone authority. However, you never need NS delegation to use any hosting service!

• Vercel, Netlify, Render, AWS, and Cloudflare all fully support CNAME / A record configuration.
• Instead of selecting "Delegate Nameservers" in your host's wizard, always select "Add CNAME record" or "External DNS Management".
• This gives you 100% of the functionality (automatic SSL, CDN caching, deployments) without needing NS delegation.

5. Signup Issue: "Please confirm you are not a robot" with No Checkbox

The Cause: Devs.Surf uses Google reCAPTCHA Enterprise v3, which is invisible by design (it evaluates behavioral signals score-wise instead of showing a puzzle box). If your browser uses an aggressive privacy extension, adblocker, or built-in shield (like Brave Shields or uBlock Origin with strict privacy lists), the reCAPTCHA API script may be blocked from loading.

6. DNS Saved in Dashboard, but Site Returns NXDOMAIN or Old IP

The Solution: When you save a record in Devs.Surf, our Anycast DNS updates authoritative nameservers immediately. If your machine still sees the old target:

1. Check Authoritative DNS Directly:

   # Query Google public DNS
   dig A yourname.devs.surf @8.8.8.8 +short
   
   # Or Cloudflare public DNS
   dig CNAME yourname.devs.surf @1.1.1.1 +short

2. Negative TTL Caching: If you requested the domain before adding records, your local ISP DNS resolver cached the "Not Found" (NXDOMAIN) state for its negative TTL duration (typically 5 to 15 minutes). Switching your DNS to 1.1.1.1 or 8.8.8.8 resolves this immediately.