How to Check If an IP Is Blacklisted and Get Delisted
A practical workflow for DNSBL checks, root-cause analysis, and responsible delisting requests.
Net Utils Blog
Clear explanations, deeper analysis, and practical guides to networking and internet infrastructure, written by the team building Net Utils.
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Public and private IPs, IPv4 and IPv6, geolocation, reputation, and subnets.
What Is a Proxy Server and When Should You Use One?
How proxies relay traffic, which types exist, and how a proxy differs from a VPN.
What Is a Subnet Mask and How Do You Read It?
How a subnet mask splits network and host bits, what CIDR means, and how ranges are calculated.
Public vs Private IP Addresses
How public and local addresses differ, how NAT works, and what CGNAT and IPv6 change.
What Is an IP Address and How Does It Work?
A clear guide to network addressing, routing, IPv4, IPv6, and public addresses.