Comprehensive and Detailed Explanation From Exact Extract of Forescout Platform Administration and Deployment:

According to the Forescout CLI Reference - Generating CSRs and Importing Signed Certificates documentation, the SSL certificate file formats compatible with CounterACT are ".p7b" and ".pem".​

Supported Certificate Formats:

According to the CLI Reference documentation:​

"To import a certificate from DER or P7B formatted files, convert it to PEM file format. Then convert the PEM files to a single PFX file as described above."

This indicates that:

P7B format - Supported (PKCS#7 container format)

PEM format - Supported and widely used (ASCII-encoded format)

Certificate Format Conversion Process:

According to the documentation:​

The standard import process is:

text

Original Format → Conversion → PEM Format → PFX Format → Import to CounterACT

├─ DER files → Convert → PEM

├─ P7B files → Convert → PEM

└─ PEM files → Direct use or convert to PFX

Why Other Options Are Incorrect:

A. .Pfx/.p12, .Pfx/.p7 - Pfx is the final format used, not input; p7 is not a standard format

C. .X.509, x.507 - X.509 is a standard (not a format); x.507 is not valid

D. .Pckcs#7, .pckcs#12 - Spelling is "PKCS," not "Pckcs"; these are standards, not file formats

E. .cer, .crt - These are certificate formats but not listed as directly compatible in the documentation

Certificate Import Workflow:

According to the documentation:​

Compatible workflow formats:

Input Formats (that need conversion):

DER files → Convert to PEM

P7B files → Convert to PEM

CER files → Convert to PEM

Intermediate Format:

PEM (ASCII-encoded, universally compatible)

Final Format:

PFX (used for CounterACT import)

Referenced Documentation:

Generating CSRs and Importing Signed Certificates - CLI Reference​

Import and Configure System Certificates