HTTP Fallback serves as a secondary transfer method when the
Internet connectivity required for Aspera accelerated transfers (i.e., UDP port
33001, by default) is unavailable. When HTTP Fallback is enabled and UDP
connectivity is lost or cannot be established, the transfer will continue over the
This feature requires configuring your settings in IBM Aspera Enterprise Server
. For details on how to perform these tasks, see the "Configuring HTTP and HTTPS Fallback" topic in your transfer product's Administrator Guide
You may configure HTTP/HTTPS
Fallback in the Aspera Enterprise Server GUI or modify aspera.conf.
To edit your settings within the GUI, launch Enterprise
Server and go to .
After modifying aspera.conf
, run the
following command (from Enterprise Server's bin
to validate your updated configuration
$ /opt/aspera/bin/asuserdata -v
What do you do if you need to change your HTTP Fallback port number?
If IBM Aspera Shares
is set to use Encryption-at-Rest,
downloading unencrypted content through HTTP Fallback will fail with the following
- Downloading unencrypted file(s) or folder(s) will fail with the
"Insufficient permissions" error.
- Downloading a mix of encrypted and unencrypted files or folders together
will fail with the "Connection lost" error.
- Downloading a mix of folders, some folders with only encrypted files and
other folders with only unencrypted files, will fail with the "Server
refused request" error.
- Downloading encrypted file(s) or folder(s) with the wrong passphrase entered
will fail with the "File decryption error, bad passphrase" error.
In the event that you need to modify your HTTP Fallback port number, configure the
following section In your aspera.conf
file (replacing <port>
with your new port number):