NetworkWhois Community
Category: Network
A, AAAA, MX, TXT Records: What to Verify First
When a domain is not behaving correctly, you do not need to check every DNS record at random. This guide shows the right order to verify A, AAAA, MX, and TXT records based on the problem you are seeing.
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How to Check DNS Records After a Migration
After moving a website, server, or mail provider, DNS mistakes are one of the most common reasons things still fail. This guide explains what to verify first and how to confirm live DNS records after a migration.
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How to Find Who Owns an IP Address With WHOIS
IP WHOIS helps you identify which organization controls an IP address, understand ASN and allocation details, and decide what to investigate next when traffic looks suspicious.
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AAAA Record Exists but IPv6 Still Fails
Publishing an AAAA record is not enough to make a service reachable over IPv6. This guide explains the most common reasons IPv6 still fails, including firewall rules, routing, listener configuration, and premature DNS changes.
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WHOIS vs Reverse DNS: What Each One Tells You
WHOIS and reverse DNS answer different questions about an IP address. This guide explains what each one reveals, when to use them together, and how they help with abuse investigation and mail troubleshooting.
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Why Reverse DNS and SPF Are Both Needed for Email
SPF and reverse DNS solve different trust problems in email delivery. This guide explains why you need both, what each one proves, and how missing PTR records still hurt sending reputation.
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IP WHOIS Lookup, How to Identify Who Owns an IP, Find the ASN, and Investigate Abuse Fast
This guide shows how to use IP WHOIS to identify who owns an IP address, understand ASN and carrier context, validate geolocation as a signal, and turn the output into practical actions, abuse reporting, blocking decisions, and correlation with reverse DNS and blacklist status.
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Why IPv6 Ping Fails, 10 Real Causes and Fixes (With Live Tests)
This guide explains why IPv6 ping often fails even when a website is online, then walks through 10 real-world causes like missing AAAA records, broken IPv6 routing, ISP path issues, and ICMPv6 firewall blocks. It shows how to test correctly using a live IPv6 ping tool, how to tell DNS problems from
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How to Check DNS Propagation, and What TTL Actually Does (With Live Checks)
When people say “DNS propagation”, they usually mean that some DNS resolvers still have the old answer cached. If you understand TTL and how to verify what different resolvers are serving, you stop guessing and start fixing.
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