What evidence do auditors commonly ask for on 1.4.5 Internal IP and routing disclosure limited?

NSC configuration showing network address translation, proxying or route filtering in place; Route advertisement filters for internal networks using registered addressing; Documented list of parties authorised to receive internal addressing information; Test results confirming internal addresses do not appear in external responses or headers.

What is the most common gap auditors find on 1.4.5?

Internal IPs leaked in HTTP headers, error pages or DNS records visible externally

PCI DSS v4.0.1 · Req 1: Network Security Controls

`1.4.5` Internal IP and routing disclosure limited

Internal IP addresses and routing information may be disclosed only to authorised parties. The guidance explains this keeps attackers from learning internal addressing, notes that methods vary with the technology (IPv4 and IPv6 may differ), and lists examples such as network address translation, placing components behind proxy servers or NSCs, filtering route advertisements, and private or privacy-extension addressing for outgoing sessions. Applicability: no special notes; applies to every assessed entity. Objective under the customized approach: internal network details are shielded from unauthorised disclosure.

Source: PCI DSS v4.0.1, 1.4.5. The statement above is our statement of the clause, read from the published text and cited so you can check it against the official text, not the instrument verbatim. Open PCI DSS v4.0.1 in the compliance library.

Version 4.0.1 is the active version; 4.0 has been retired. Appendix A1 applies only to multi-tenant service providers, A2 only to card-present POS POI terminals that still use SSL or early TLS, and A3 only when a payment brand or acquirer requires it. Which requirements apply to you follows your validation type.

artefacts

held by a system

at each review

moderate

to go live

Cloud console / configuration management

where the evidence lives

teal = a system already holds it · olive = produced at each review. To go live: easy when half or more of the artefacts are already held by a system, moderate from a quarter to a half, hard below a quarter.

These are the artefacts auditors commonly ask for on this requirement, our guidance rather than text from the standard. Your assessor decides what is sufficient in your context, and asks for samples across the period when a report covers one.

system holds itEvidence a system already holds

NSC configuration showing network address translation, proxying or route filtering in place · Cloud console / configuration management

periodic reviewEvidence produced at each review

Test results confirming internal addresses do not appear in external responses or headers · Source control / CI pipeline

governing documentDocuments that govern the control

Route advertisement filters for internal networks using registered addressing · Policy repository / GRC workspace
Documented list of parties authorised to receive internal addressing information · Policy repository / GRC workspace

First move

Start with the 1 of 4 artefacts that already live in a system (Cloud console / configuration management); keep the periodic reviews but log each one as a dated record with a named reviewer.

Common gaps auditors find

Internal IPs leaked in HTTP headers, error pages or DNS records visible externally
Internal routes advertised to upstream providers
Network diagrams with addressing shared with vendors without authorisation

Do this for your whole sheet

Paste the rows you run your controls from and get this mapping for every control at once, with the periodic-review ones flagged and a first move per row. No account for the first run.

Build my evidence sheet

1.4.4 Cardholder data stores not reachable from untrusted networks · 1.5.1 Security controls on dual-connected devices