> Source: [sk183853](https://support.checkpoint.com/results/sk/sk183853)

# sk183853 - FTP traffic does not pass through Security Gateway when using the FTP "Extended Passive Mode"

| Property | Value |
|----------|-------|
| Solution ID | sk183853 |
| Date Created | 2025-09-02 |
| Last Modified | 2026-07-23 |
| Technical Level | Advanced |
| Products | Security Gateway |
| Versions | R82.10, R82, R81.20, R81.10 (EOS) |
| OS | Gaia |

## Symptoms

- * FTP traffic does not pass through Security Gateway when using the FTP "Extended Passive Mode", although an explicit Access Control rule is configured.

* SmartConsole logs show that the Security Gateway drops this FTP traffic on a Clean Up rule.

* Kernel debug (`fw ctl debug -m fw + conn drop vm ftp`) on the Security Gateway shows that it drops the FTP traffic because of an illegal format.

  Example:

  `;fw_post_vm_chain_handler: executing handler function ftp_pasv_code;`  
  `
  ;fw_do_ftp6port: data = XXX Entering Extended Passive Mode (!!!XXX!).`  
  `
  ;fw_do_ftp6port: XXX command;`  
  `
  ;fw_do_ftp6port: illegal format.;`

## Cause

In the FTP "EPSV" command, the FTP server uses a character that is not the pipeline character "`|`" (for example, and exclamation sign "`!`") as the delimiter (see [RFC 2428](https://www.rfc-editor.org/rfc/rfc2428)).

Security Gateway supports only the pipeline character "`|`" as the delimiter in the FTP "EPSV" command.

## Solution

This solution requires authentication. Please log in to view the full solution.

---

# Agent Instructions

This content is from the Check Point Support Center (https://support.checkpoint.com), the official knowledge base for Check Point cybersecurity products.

## Navigating This Knowledge Base

- **Complete index**: [llms.txt](https://support.checkpoint.com/llms.txt)
- **All SK articles**: [SecureKnowledge Sitemap](https://support.checkpoint.com/sitemaps/secureknowledge-sitemap-index.xml)
- **SK article URL pattern**: `https://support.checkpoint.com/results/sk/{skId}`
- **Markdown responses**: AI bot User-Agents automatically receive `text/markdown` content