DNS
Child Nameservers vs. External Zone Delegation Explained
Learn how child nameservers, glue records, and subdomain delegation work, where each is configured, and when to use one over the other.
189 articles in DNS
Sort by
DNS
What is a DNS Amplification Attack? (DDoS Reflection)
A DNS amplification attack spoofs the victim's IP to trigger massive reflected responses from open resolvers, using EDNS0's larger buffer sizes (up to 4096 bytes) to turn a 60-byte request into a 3,000-byte response, roughly 50x amplification. Mitigation includes Response Rate Limiting, closing open recursion, and upstream scrubbing.
DNS
Authoritative vs. Recursive DNS Servers Explained
Learn the difference between recursive DNS resolvers and authoritative nameservers, how caching works, and where each fits in a DNS lookup.
DNS
Setting Up Custom Nameservers (Glue Records) for Agencies
Learn how glue records work, why custom nameservers need them, and how agencies can configure branded nameservers such as ns1.yourdomain.com.
DNS
What is the DNS Root Zone and How Does It Work?
The DNS root zone is the top of DNS hierarchy, listing every TLD's nameservers. It's hosted on 13 named root server identities (A-M), which Anycast routing expands into over 2,000 physical instances worldwide. IANA maintains the file; the root has never suffered a complete outage, even under major DDoS attacks.
DNS
How to Verify Domain Ownership for Meta Business Manager
Learn how to verify domain ownership for Meta Business Manager using a DNS TXT record, HTML file, or meta tag, with NameSilo DNS setup steps.
DNS
What Is a DS Record and How Does It Enable DNSSEC?
A DS record at the parent registry authenticates your domain's DNSSEC key, establishing a chain of trust that stops cache poisoning and MITM attacks. Golden rule: always remove the DS record before changing nameservers or DNS hosts, or every validating resolver returns SERVFAIL and your domain disappears.
DNS
Updating DNS Records Programmatically via the NameSilo API
Automate DNS management with NameSilo's API using dnsListRecords, dnsAddRecord, dnsUpdateRecord, and dnsDeleteRecord. Always call dnsListRecords first to retrieve the record_id before updating or deleting; note it's passed back as rrid in update and delete calls. Useful for DDNS and Let's Encrypt wildcard verification.
DNS
What is a DKIM Selector and How Do You Find It?
A DKIM selector identifies which public key to check in DNS, following the format selector._domainkey.yourdomain.com. Find it in your provider's admin console (Google Workspace defaults to "google"; Titan Mail shows it under Email Reputation) or by inspecting the s= tag in a raw email header.
DNS
ALIAS Records vs. CNAME Records: Which Do You Need?
RFC 1035 forbids CNAME records at a root domain because they conflict with MX and NS records. ALIAS, ANAME, and CNAME flattening are vendor-specific workarounds, not a DNS standard. NameSilo doesn't currently offer ALIAS/ANAME; use CNAME on www plus root forwarding, or delegate DNS to a provider like Cloudflare that supports it.
DNS
How to Find and Fix Redirect Chains on Your Website
A redirect chain (A > B > C) wastes crawl budget and slows load times. Googlebot abandons chains after roughly 10 hops. The most common cause is HTTP to HTTPS to WWW stacking. Fix by flattening .htaccess or Nginx rules into a single 301 redirect straight to the final URL.
DNS
How to Find the Origin IP Address Behind Cloudflare
Audit your own Cloudflare setup for origin IP exposure: unprotected MX and subdomains, historical DNS records, and certificate transparency logs. Enabling the orange cloud alone does not erase a previously public IP. Lock the origin firewall to Cloudflare's IP ranges to close the gap.