# Firewall Considerations

> This article contains information on inbound and outbound ports that the application will use.

URL: https://www.hannonhill.com/cascadecms/latest/articles/cascade-administration/installation-and-upgrades/system-configuration/firewall.html
category: Cascade Administration
article-type: reference
content-kind: article
release-availability: all
tags: security, installation
updated: 2026-10-06

## Inbound connections

**Inbound Ports**

| Default Port | Used for |
| --- | --- |
| 80 | HTTP |
| 443 | HTTPS |
| 8080 | HTTP |
| 8443 | HTTPS |

## Outbound connections

**Outbound Ports**

| Default Port | Used for |
| --- | --- |
| 21 | FTP, FTPS |
| 22 | SFTP |
| 25 | SMTP* |
| 80 | Link checking**, Connectors |
| 389 | LDAP |
| 443 | Link checking** |
| 636 | LDAPS |
| 990 | FTPS |
| 1433 | SQL Server |
| 1521 | Oracle |
| 3306 | MySQL, MySQL Database Publishing |

> **Note**
>
> As of Cascade CMS 8.13+, most system-generated emails will be sent via an external service (SendGrid). If you are not receiving emails from within the application, you may need to allow deliveries from `*.sendgrid.com` at your email server to allow for deliveries. These emails will come from `noreply@cascadecms.com`. If you are using a proxy, Cascade CMS 8.16+ allows for configuring outbound connections for email as described [in this article](https://www.hannonhill.com/cascadecms/latest/articles/cascade-administration/installation-and-upgrades/system-configuration/email-proxy-support.html).

> **Note**
>
> Since end users can link to any URL and port, the external link check could require other outbound ports for specific URLs. In general, you should be ok with only allowing port 80 and port 443.