FTP and FTPS

FTP is popular for business-to-business integration, and the appliance supports it fully.

Connection Information

The settings below cover the most common FTP connection issues. Double-check each of them.

Hostname

Connect with either FTP or FTPS to the fully qualified domain name of your appliance. If your client requires an IP address, connect using the external IP address configured in the appliance manager.

Port

For unencrypted FTP, use the default FTP port 21.

For FTPS, use implicit FTP mode in your client and port 990.

Suggested Client Settings

The settings below give the best file transfer performance and mitigate transient errors without manual intervention:

• Timeout: 300 seconds

• Retries: 5

• Delay: 90 seconds

The delay allows failover to occur when an individual server host stops responding. The system detects these issues, spins up a new host, and directs new requests to it.

Failover will not work correctly when a hard-coded IP address is used instead of a domain name.

Most FTP clients expose these settings, and command-line automations can be scripted to loop and wait. In FileZilla the settings live under FileZilla > Settings > Connection as shown below.

• Active vs. Passive mode: Passive mode

Passive mode sends each file through its own channel and is more performant when sending multiple files.

• Keep-alives are not needed unless your FTP client is aborting file transfers due to the control channel being closed when idle. Most FTP clients do not need this.

• Simultaneous transfers: 10

Each user is permitted to upload and/or download up to 10 files at the same time. It is also the maximum supported by FileZilla. Transfers beyond 10 are placed into a first-in, first-out queue on the client side.

If you are experiencing intermittent transfer errors, reducing this value may help.

• ASCII vs. Binary mode: Binary mode

No matter the file extension or mime-type, all files are stored exactly as they are when uploaded, byte for byte. You can compare the MD5 checksum on both sides to verify that no corruption of data has taken place.

Systems that depend on ASCII mode support are not compatible.

• Logging: Enabled with timestamps

This is to aid in troubleshooting and with filing a support ticket.