CyberGuard dictionary / Network Security
Public IP
A public IP address is an Internet address intended for globally reachable routing, subject to network policy and address allocation.
In simple terms
A public address can identify an endpoint that other networks can route toward, though firewalls and NAT may still block direct connections.
Technical explanation
Globally unique address blocks are allocated through Internet registry processes. Seeing a public address in a request does not prove which person or internal device originated it, especially when many users share a translator.
A public IP is routable on the internet, but exposure also depends on firewall rules and listening services. The address may change or represent many devices behind a gateway.
Examples in practice
A website receives requests from a company's public gateway address even though staff devices have separate private addresses.
A cloud server has a public address yet accepts only HTTPS from visitors and management access from a restricted network. An inventory review catches an accidental new open port.
Why it matters
Public addressing helps trace paths, but access control and attribution need more than the IP value alone.
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Sources and further reading
- www.rfc-editor.orghttps://www.rfc-editor.org/info/rfc791/↗
- www.rfc-editor.orghttps://www.rfc-editor.org/info/rfc3022/↗
Published 2026-10-15 · Last updated 2026-10-15 · CyberGuard editorial content. Source links provide context; they do not imply endorsement.