FTP Server Connector

FTP Server connectors provide connection credentials to access the full-featured Arc FTP Server.

Key Capabilities

Full-featured embedded FTP server with FTPS (FTP over TLS/SSL) support
Multi-client architecture with individual user profiles and directory isolation
Configurable permissions for send and receive directories per trading partner
Welcome banners, file filtering, and temporary file handling for reliable operations
Support for both active and passive modes with configurable port ranges

Overview

The Arc FTP Server is primarily configured on the Profiles page. Then, individual FTP Server connectors provide a unique client profile to authenticate to the FTP Server. The client profile consists of a username (which matches the FTP Server connector’s Connector Id), a password, a set of send and receive directories, and permissions to read and/or write files in these directories. FTP clients are not given permissions to the root of the FTP Server, which means that FTP clients should always cd into the send (to download) and receive (to upload) directories after connecting.

Video Resources

Watch this short video for an overview of how to configure an FTP Server. The video uses an SFTP Server in the example, but the principles are the same for FTP.

Profile Configuration

The FTP Server Profile must be configured before connections can be established with individual FTP Server connectors. Click Profiles on the navbar, then click the FTP Server tab.

Server Configuration

Server implementation settings.

Setting	Description
Port	The port on which the FTP Server listens for incoming connections.
FTP Over TLS	How TLS/SSL should be negotiated when clients connect to the server. Choose Explicit to establish a plain text connection where TLS/SSL is then started with an explicit command. Choose Implicit to immediately negotiate TLS/SSL without establishing a plain text connection.
Server TLS Certificate	The TLS certificate that identifies the server. Only required if the server is operating as an FTPS server (in other words, if TLS/SSL is enabled).
Certificate Password	The password required to access the Server TLS Certificate.
Welcome Message	The banner presented to FTP clients when they connect to the server.
Root Directory	The root directory for the server. Subfolders are created in the root for individual client profiles (in other words, for each configured FTP Server connector). Each client profile includes a Send folder, where clients can download files from the server, and a Receive folder, where clients can upload files to the server.
Allowed Files Filter	A glob pattern that determines which files are accepted by the FTP server. You can use negative patterns to indicate files that should not be downloaded (for example, -.tmp). Separate multiple file types by commas (for example, .x12,*.edi).

Other Settings

Settings that do not fall into the previous category.

Setting	Description
Active Mode	Check this to enable Active mode on the remote FTP server. Keep in mind that Passive mode is less likely to result in firewall interference with the connection.
Inactivity Timeout	The length of time (in seconds) that must pass without activity for a user to time out.
Passive Port Range	When using Passive mode, the application uses any available port to listen for incoming data connections. You can override this by setting this field to a port range in `start-end` format. For example: `1024-` refers to ports higher than 1024 (inclusive) and `1024-2048` refers to ports between 1024 and 2048 (inclusive).
Passive Address	When using Passive mode, the application returns the IP address for the local interface. You can override this by setting this field to a specific public IP address.
TLS Enabled Protocols	The list of TLS/SSL protocols supported when establishing outgoing connections. Best practice is to only use TLS protocols. SSL v2 and SSL v3 are considered vulnerable and should only be used if your partner does not support higher versions. Keep in mind that TLS v1.3 is not universally adopted, and might be refused if the destination server does not support it.

Logging

Settings that govern the creation and storage of logs.

Setting	Description
Log Level	The verbosity of logs generated by the connector. When you request support, set this to Debug.
Log Rotate Interval	The number of days to wait before creating a new log file.
Log Delete Interval	The number of days to wait before deleting old log files.

Miscellaneous

Miscellaneous settings are for specific use cases.

Setting	Description
Other Settings	Enables you to configure hidden connector settings in a semicolon-separated list (for example, `setting1=value1;setting2=value2`). Normal connector use cases and functionality should not require the use of these settings.

Connector Settings

Once you configure the FTP Server profile settings, create and configure an individual FTP Server connector for each trading partner on the Flows page.

Settings Tab

Configuration

Setting	Description
Connector Id	The static, unique identifier for the connector.
Connector Type	Displays the connector name and a description of what it does.
Connector Description	An optional field to provide a free-form description of the connector and its role in the flow.

Server Status

The current state of the connector's underlying service. The following statuses are available:

Status	Description
Active	The service is running.
Inactive	The service is configured but is not currently running.
Not Configured	The underlying profile or service has not been set up.

Depending on whether you have already created the FTP profile, click the Configure FTP Profile or View FTP Profile links to open the profile in a new tab.

User Configuration

Credentials for authenticating to the local FTP server.

Setting	Description
User	The username credential for logging in to the local FTP server. This value is always the same as the Connector Id.
Password	The password credential associated with the User.

Permissions

Settings related to the read and write permissions the configured client has for the Send and Receive folders.

Setting	Description
Send Directory Permissions	Use the checkboxes to set read and write permissions for the Send directory. This directory is where files are downloaded.
Receive Directory Permissions	Use the checkboxes to set read and write permissions for the Receive directory. This directory is where files are uploaded.

Advanced Tab

Local Folders

Settings related to the folders where clients upload and download files.

Setting	Description
Input Folder (Send)	Files in the Send folder are available to be downloaded by clients.
Output Folder (Receive)	Files uploaded by the client are placed in the Receive folder. Files remain in the Receive folder or are passed along to the next connector in the flow.

Other Settings

Settings not included in the previous categories.

Setting	Description
Home Directory	The configured server path where connected users start after logging in. For the valid locations and how the path is validated, see Home Directory.
Allowed Files Filter	A glob pattern that determines which files are accepted by the FTP server. Overrides the Allowed Files Filter option on the FTP Profile page.
Remove File After Send	Whether files in the Send folder should be removed after the client receives them.
Temp Receive Extensions	Files with a matching extension are not recorded in the Receive table and do not fire the After Receive event until they are renamed. Supply a comma-delimited list of file extensions.
Timeout	The length of time (in seconds) the server waits for a connection response before throwing a timeout error.
Save Subfolder	Check this to add a SubFolder header to received messages. This header represents the path relative to the Local Folders.
Local File Scheme	A scheme for assigning filenames to messages that are output by the connector. You can use macros in your filenames dynamically to include information such as identifiers and timestamps. For more information, see Macros.

Message

Message settings determine how the connector searches for messages and manages them after processing.

Note: The settings below are deprecated and hidden by default. They appear only on connectors where they were previously enabled or configured to a non-default value. To retain copies of successfully processed files, right-click the connector in the flow, choose Show Success Path, and connect the success path to a File connector.

Setting	Description
Save to Sent Folder (Deprecated)	Copies files processed by the connector to the Sent folder. Disabled by default. Files saved to the Sent folder are not covered by Encryption at Rest.
Sent Folder Scheme (Deprecated)	Groups files in the Sent folder by the selected time interval. Only relevant when Save to Sent Folder is enabled.

Logging

Settings that govern the creation and storage of logs.

Setting	Description
Log Level	The verbosity of logs generated by the connector. When you request support, set this to Debug.
Log Subfolder Scheme	Instructs the connector to group files in the Logs folder according to the selected interval. The Weekly option (which is the default) instructs the connector to create a new subfolder each week and store all logs for the week in that folder. Leaving this setting blank tells the connector to save all logs directly in the Logs folder. For connectors that process many transactions, using subfolders helps keep logs organized and improves performance.
Log Messages	Check this to have the log entry for a processed file include a copy of the file itself. If you disable this, you might not be able to download a copy of the file from the Transactions tab.

Miscellaneous

Miscellaneous settings are for specific use cases.

Setting	Description
Other Settings	Enables you to configure hidden connector settings in a semicolon-separated list (for example, `setting1=value1;setting2=value2`). Normal connector use cases and functionality should not require the use of these settings.

Alerts Tab

SLAs Tab

Establishing a Connection

Each FTP Server connector represents a single trading partner’s connection parameters. The trading partner should connect to the FTP server using the server settings (such as port and TLS mode) from the Profile page and the user configuration settings in the dedicated FTP Server connector (User and Password). Each trading partner has separate Send and Receive directories that are subfolders of the root. The partner should download files from the Send folder and upload files to the Receive folder. The client is not permitted to upload or download files from the root.

Home Directory

The Home Directory setting controls which folder a client lands in when it logs in to an FTP Server connector. Configure it in the connector’s Advanced tab, under Other Settings. Setting a home directory is useful when you migrate from other FTP software that let you configure a landing folder, or for automated systems that upload or download at whatever directory they land in without issuing navigation (cd) commands. The field defaults to empty, but it also accepts a server path:

Empty (default): The client lands at the virtual root (/).
Set to a path: On successful login, the client’s initial working directory is the specified path. A client that connects and immediately uploads, downloads, or lists files without changing directories operates inside the home directory.

The home directory must be a server path (starting with /) that resolves against the Root Directory defined on the connector’s Profile, and it must match a configured server location; you cannot set it to an arbitrary path that only exists on disk. For the FTP Server connector, the valid locations are:

/ (the virtual root): this is the default when the field is empty, so setting it explicitly has no additional effect
/Send
/Receive

The field normalizes your input, so Receive, /Receive, \Receive, and /Receive/ are all treated as the same path. The value is validated when you save the connector: a path that does not match a configured server location is rejected with an error that names the invalid value.

The home directory only sets the initial landing directory at login. It is not a chroot or jail and does not restrict which folders a client can navigate to afterward; folder access is still governed by the permission settings.

Macros

Examples

Common Errors

Error: Could not bind server socket: Permission denied.

Cause This error can appear when you attempt to connect to an FTP server and the process hosting Arc does not have sufficient privileges to establish a listener on the specified port.

In some cases (such as Linux environments and hosted instances running in an Amazon AMI), you cannot use ports below 1024.

Resolution Choose a different port, or change the identity of the process hosting Arc to one with permissions to bind to the port. The Amazon AMI-hosted version of Arc uses the Ubuntu operating system, so CData recommends that you use an Uncomplicated Firewall (UFW) to manage port permission issues. For example, setting up FTP Server to run on port 8021 in Arc and using UFW to forward port 21 to 8021 at the OS level looks like this:

ufw allow 21/tcp
ufw allow 8021/tcp
echo "
*nat
:PREROUTING ACCEPT [0:0]
-A PREROUTING -p tcp --dport 21 -j REDIRECT --to-port 8021
COMMIT" >> /etc/ufw/before.rules

If your environment uses a different Linux operating system, CData recommends that you bind to a port above the restricted range (for example, 8021 for FTP traffic) and use iptables to route incoming requests on the desired port to the allowed port: iptables -t nat -I PREROUTING -p tcp --dport 21 -j REDIRECT --to-port 8021

Getting Started

Flows

EDI Trading Partner Management Console

Connectors

Mapping

APIs and Automation

How-To Guides

Scripting

Software License and Third-Party Copyrights

Key Capabilities

Overview

Video Resources

Profile Configuration

Server Configuration

Other Settings

Logging

Miscellaneous

Connector Settings

Settings Tab

Configuration

Server Status

User Configuration

Permissions

Advanced Tab

Local Folders

Other Settings

Message

Logging

Miscellaneous

Alerts Tab

SLAs Tab

Establishing a Connection

Home Directory

Macros

Examples

Common Errors

Error: Could not bind server socket: Permission denied.

​Key Capabilities

​Overview

​Video Resources

​Profile Configuration

​Server Configuration

​Other Settings

​Logging

​Miscellaneous

​Connector Settings

​Settings Tab

​Configuration

​Server Status

​User Configuration

​Permissions

​Advanced Tab

​Local Folders

​Other Settings

​Message

​Logging

​Miscellaneous

​Alerts Tab

​SLAs Tab

​Establishing a Connection

​Home Directory

​Macros

​Examples

​Common Errors

​Error: Could not bind server socket: Permission denied.

Key Capabilities

Overview

Video Resources

Profile Configuration

Server Configuration

Other Settings

Logging

Miscellaneous

Connector Settings

Settings Tab

Configuration

Server Status

User Configuration

Permissions

Advanced Tab

Local Folders

Other Settings

Message

Logging

Miscellaneous

Alerts Tab

SLAs Tab

Establishing a Connection

Home Directory

Macros

Examples

Common Errors

Error: Could not bind server socket: Permission denied.