> Source: [sk183637](https://support.checkpoint.com/results/sk/sk183637)

# sk183637 - Connections fails to port 5555 on Spark Firewall

| Property | Value |
|----------|-------|
| Solution ID | sk183637 |
| Date Created | 2025-07-17 |
| Last Modified | 2025-10-29 |
| Technical Level | General |
| Products | Spark Firewall (Locally Managed) |
| Versions | R81.10.X |
| Platform | 1570R, 1500, 1900, 2000, 1600, 1800, 1595R |

## Symptoms

- * All incoming connections to port 5555 are dropped.

* The WebUI or SSH access logs show:

  *"Description: WebUI/SSH access attempt from unallowed source"*
* The connections are dropped regardless if the port is defined as a server or through NAT.

* Attempting to allow access from any source does not resolve the issue.

## Cause

Port 5555 is used as a reserved backend service port.

Attempting to use this port for custom services or NAT mappings causes conflicts that result in connection failures and system log errors.

## Solution

This problem was fixed. The fix is included starting from:

* [R81.10.17](https://support.checkpoint.com/results/sk/sk183153) starting from Build 996004749

After you upgrade to the recommended build, update the access port to avoid conflicts with the reserved backend port 5555:

**In CLI**

1. Connect to the command line on the Security Gateway.

2. If your default shell is Gaia Clish, log in to the Expert mode:

   `expert`
3. Run this command:

   `fw ctl set int sfw_access_ssh_web_port <NEW_PORT>`

   Make sure to replace \<NEW_PORT\> with a value that is not reserved by the system.

**In WebUI**

1. Log in to the appliance and go to **Device** \> **Advanced** \> **Advanced Settings**.

2. Open the **Shell server - Shell port** attribute.

3. In the **Shell port** field, manually enter a new port number.

4. Click **Save**.

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