Prior to SmartServer 4.2, the SmartServer Configuration page Firewall tab was called the Features tab.

For SmartServer 4.1 and prior, see Managing Ports and Services (Release 4.1 and Prior).

This section consists of the following topics:

Identifying Outgoing Internet Requests

The following functions may attempt outgoing Internet requests while using the SmartServer:

• NTP – SmartServer synchronizes time using http://ntp.pool.org/.

• Certificates – if you are using signed certificates, then the SmartServer will periodically renew certificates by going to Let's Encrypt.

• DDNS – the public IP address of the SmartServer's private network is registered in order to allow outside users to contact the SmartServer by its hostname. This operations entails going to AWS (location of DDNS service).

• Google Maps and Open Street Maps – the Locations widget accesses external mapping APIs.

• wget – SmartServer accesses the SmartServer download server when you update the SmartServer using the Internet method for the update source.

• Node-RED – if you are using Node-RED (Sequencing widget), then some functions may try to access the Node-RED server.

Identifying External Ports

The table below lists the incoming and/or outgoing service ports that are open to the outside world by default. The default is set when re-imaging the system and when transitioning the Enable Enhanced Security option from disabled to enabled. You can sort the table by clicking on the column header.

When the Enable Enhanced Security option is checked (enabled), all of the ports listed in the table are opened, except for the ports that are marked with asterisks (**). These ports are only open by default if the service is enabled in the SmartServer Configuration pages. The consequence of closing these ports is described in the column labeled Consequence of  Closing. 

Other services can be managed from the command line using ufw firewall rules. See the Disabling / Re-enabling Other Ports section below for more information. You can optionally create a backup of the following files in case you want to undo any changes to the firewall rules:

/etc/ufw/user.rules
/etc/ufw/user6.rules

Identifying Internal Ports

The table below lists internal services/ports. There are no firewall rules exposing these internal services/ports to external interfaces. You can sort the table by clicking on the column header.

Enabling / Disabling MQTT Ports

Starting with SmartServer 2.7 Update 1, you can enable and disable the MQTT ports on the LAN (eth0) and WAN (eth1) interfaces from the SmartServer Configuration page.  These ports are used to provide external access to the IAP/MQ message bus used internally by the SmartServer.  The MQTT ports are 1883 for unsecure communication and 8883 for TLS encrypted secure communication.

To enable or disable either of these ports, perform the following steps:

1. Open the SmartServer Configuration page as described in Accessing the SmartServer IoT Configuration Page. The Network tab appears as the default SmartServer Configuration page. Once the network settings are configured for the SmartServer system, then the System tab will appear.
   
   
   SmartServer IoT Network tab
   
   
   SmartServer IoT System tab
   
   

2. Click the Firewall tab. 
   
   The Firewall tab appears.
   
   
   
   

3. Select the check boxes for the ports you want to enable; clear the checkboxes for the ports you want to disable.
   
   
   
   
4. Click Update to save the port settings.

Disabling SSH / Port 22

To disable SSH port 22, perform the following steps:

1. Log into the SmartServer console using USB or SSH.
   
   

2. Enter the following command to view current firewall rules:


   sudo ufw status numbered

3. Take note of the rule number for SSH port 22.
   
   
   
   

4. Delete the rule for SSH port 22 using the following command (may require sudo password):

   sudo ufw delete <rule number for port 22>

   The following confirmation prompt appears:

   Proceed with operation (y|n)?

5. Enter y and press RETURN.

   Once the rule number for port 22 is deleted, SSH connection attempts will timeout and fail to connect.
   
   
   Example: disables the SSH port 22
   

   Disabling SSH service

   You can also disable the SSH service; however, this service will be re-enabled after upgrading or re-imaging the SmartServer. To disable the SSH service, enter the following commands:

   sudo systemctl disable ssh
   sudo systemctl stop ssh

Disabling / Re-enabling Other Ports

Starting with SmartServer 3.5, the default for all outgoing and incoming ports is set to deny. In order to enable a port through the firewall, a rule needs to be created, and to disable a port through the firewall, a rule needs to be deleted.

To disable a port by deleting a firewall rule, perform the following steps:

1. Log into the SmartServer console using USB or SSH.
   
   

2. Enter the following command to view current firewall rules:

   sudo ufw status numbered

   

   
   

3. Take note of the current settings and only remove specific rules by entering the following command (may require sudo password):

   sudo ufw delete <rule number>

   Example

   sudo ufw delete 24

   
This example disables the outbound ephemeral UDP port range.



   Note the syntax for enabling the rule

   Take note of the response to the delete command (i.e., allow out 49152:65535/udp in the example below) as shown in the highlighted area of the following screen capture. You will need this syntax if you later want to re-enable the port.
   
   

   
   The following confirmation prompt appears:

   Proceed with operation (y|n)?

4. Enter y and press RETURN.
   
   The rule is deleted.
   
   
   
   

To re-enable a port by adding a firewall rule, perform the following steps:

1. Log into the SmartServer console using USB or SSH.
   
   

2. Enter the following command to add a rule:

   sudo ufw <allow syntax that was noted above>

   Example

   sudo ufw allow out 49152:65535/udp

   
The rule is added.
   
   

Changing the HTTP and HTTPS Ports

The SmartServer defaults to using port 80 for HTTP and 443 for HTTPS. In some cases, you will want to change these ports in order to make HTTP and HTTPS more secure. The instructions below show how to change the http port from 80 to 1780,  and https from 443 to 1443. 

To change both of these ports you have to do the following:

1. Backup the /etc/nginx/sites-available/apollo.conf.  Use ssh/console (use apollo login) or SFTP (requires root login).
    

   Making a copy of apollo.conf using console/ssh

   ls -l /etc/nginx/sites-available/
   sudo cp /etc/nginx/sites-available/apollo.conf /etc/nginx/sites-available/apollo.conf.old
   ls -l /etc/nginx/sites-available/

2. Change three lines in the apollo.conf file.

   Console/SSH using nano

   sudo nano /etc/nginx/sites-available/apollo.conf

   1. Default settings are as follows:

      apollo.conf default settings for HTTP (80) ports

      listen                  80 default_server;
      listen             [::]:80 default_server ipv6only=on;

      apollo.conf default settings for HTTPS (443) ports

      listen                  443 ssl;

   2. After HTTP port is changed from port 80 to port 1780, and after HTTPS port changed from 443 to 1443.

      apollo.conf default settings for HTTP (1780) ports

      listen                  1780 default_server;
      listen             [::]:1780 default_server ipv6only=on;

      apollo.conf default settings for HTTPS (1443) ports

      listen                  1443 ssl;

   3. Save the file.

   4. Verify changes.

      Verify the change were made

      cat /etc/nginx/sites-available/apollo.conf
      
      :
      server {
          # listen on HTTP port(s) (this is the default server)
          # NOTE: Only use non-SSL ports for debugging!
          listen                  1680 default_server;
          listen             [::]:1680 default_server ipv6only=on;
          server_name "";
          return 301 https://$host$request_uri;
      }
      
      server {
          # listen on IPv4 HTTPS port (using a self-signed certificate)
          # DOC: <http://nginx.org/en/docs/http/configuring_https_servers.html>
          # DOC: <http://www.akadia.com/services/ssh_test_certificate.html>
          listen                  1443 ssl;
      
      :

3. Determine what ports are open.

   1. Enter the following command:

      sudo ufw status numbered 

      
      



      Each port number can have multiple entries and can be input or outputs.



4. Open new ports for HTTP (1780) and HTTPS (1443). Remove the port 80 and 443 IN ports, but keep the port 80 and 443 Output ports. The port 80 and 443 output entries are used by the SmartServer internal applications to access external servers and should not be changed. 

   Close some port 80 and 443 entries, and add new 1780 and 1443 port entries

   sudo ufw allow 1780
   sudo ufw allow 1780/tcp
   sudo ufw allow out 1680/tcp
   sudo ufw allow 1443/tcp
   sudo ufw allow 1443
   sudo ufw allow out 1443/tcp
   
   sudo ufw delete allow 80/tcp
   sudo ufw delete allow 443
   sudo ufw delete allow 443/tcp
   
   

5. Verify that port setting are correct. Make sure that 80/tcp ALLOW OUT and 443/tcp ALLOW OUT are still allowed.

   Ports open after changes

   $ sudo ufw status numbered
   Status: active
   
        To                         Action      From
        --                         ------      ----
   [ 1] 22/tcp                     ALLOW IN    Anywhere
   [ 2] 5353/udp                   ALLOW IN    Anywhere
   [ 3] 2541/udp                   ALLOW IN    Anywhere
   [ 4] 2541/udp                   ALLOW OUT   Anywhere                   (out)
   [ 5] Anywhere on lo             ALLOW IN    Anywhere
   [ 6] Anywhere                   ALLOW OUT   Anywhere on lo             (out)
   [ 7] Anywhere                   DENY IN     127.0.0.0/8
   [ 8] 53/udp                     ALLOW OUT   Anywhere                   (out)
   [ 9] 5353/udp                   ALLOW OUT   Anywhere                   (out)
   [10] 80/tcp                     ALLOW OUT   Anywhere                   (out)
   [11] 443/tcp                    ALLOW OUT   Anywhere                   (out)
   [12] Anywhere                   ALLOW OUT   Anywhere on ip70           (out)
   [13] 123/udp                    ALLOW OUT   Anywhere                   (out)
   [14] 25/tcp                     ALLOW OUT   Anywhere                   (out)
   [15] 502/tcp                    ALLOW OUT   Anywhere                   (out)
   [26] 1443                       ALLOW IN    Anywhere
   [17] 1628/udp                   ALLOW IN    Anywhere
   [18] 1628/udp                   ALLOW OUT   Anywhere                   (out)
   [19] 1883 on eth0               ALLOW IN    Anywhere
   [20] 8883 on eth0               ALLOW IN    Anywhere
   [21] 1780/tcp                   ALLOW IN    Anywhere
   [22] 1780/tcp                   ALLOW OUT   Anywhere                   (out)
   [23] 1780                       ALLOW IN    Anywhere
   [24] 1443/tcp                   ALLOW IN    Anywhere
   [25] 1443/tcp                   ALLOW OUT   Anywhere                   (out)
   
   

6. Reboot the SmartServer.