A network allowlist is a policy that permits only explicitly approved network destinations, services, or communication paths. It matters because least-privilege networking is stronger when systems cannot reach every destination by default.
What is Network Allowlist?
Allowlisting can apply to IP ranges, domains, ports, protocols, services, or peer relationships. It is used to reduce exposure, tighten trust boundaries, and make unexpected communication more visible and suspicious.
What Network Allowlist Commonly Supports
Common uses include outbound control, server hardening, application isolation, zero-trust networking, and partner access restriction.
Network Allowlist vs. Network Denylist
An allowlist blocks by default and permits selected communication. A denylist allows by default and blocks only known-bad or disallowed items.
Frequently Asked Questions
Why are allowlists stronger than denylists?
Because they start from least privilege rather than assuming most communication is fine unless it is specifically known bad.
What is the challenge?
They can require more discovery, maintenance, and change discipline to avoid breaking legitimate workflows.
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