Configuring the Firewall

Required firewall settings.

Your Aspera transfer product requires access through the ports listed in the table below. If you cannot establish the connection, review your local corporate firewall settings and remove the port restrictions accordingly.

Product Firewall Configuration
Enterprise Server An Aspera server runs one SSH server on a configurable TCP port (22 by default).
Important: Aspera strongly recommends running the SSH server on a non-default port to ensure that your server remains secure from SSH port scan attacks. For instructions on how to change your SSH port, see Securing your SSH Server.
Your firewall should be configured as follows:
  • Allow inbound connections for SSH, which is on TCP/22 by default, or on another non-default, configurable TCP port. To ensure that your server is secure, Aspera recommends allowing inbound SSH connections on TCP/33001, and disallowing inbound connections on TCP/22. If you have a legacy customer base utilizing TCP/22, then you can allow inbound connections on both ports. Please refer to the topic Securing your SSH Server for details.
  • Allow inbound connections for FASP transfers, which use UDP/33001 by default, although the server may also choose to run FASP transfers on another port.
  • If you have a local firewall on your server (like iptables), verify that it is not blocking your SSH and FASP transfer ports (such as TCP/UDP 33001).

The firewall on the server side must allow the open TCP port to reach the Aspera server. Note that no servers are listening on UDP ports. When a transfer is initiated by an Aspera client, the client opens an SSH session to the SSH server on the designated TCP port and negotiates the UDP port over which the data transfer will occur.

Client Typically, consumer and business firewalls allow direct outbound connections from client computers on TCP and UDP. In this case, no configuration is required for Aspera transfers. In the special case of firewalls disallowing direct outbound connections, typically using proxy servers for Web browsing, the following configuration applies:
  • Allow outbound connections from the Aspera client on the TCP port (TCP/33001 by default, when connecting to a Windows server, or on another non-default port for other server operating systems).
  • Allow outbound connections from the Aspera client on the FASP UDP port (33001, by default).
  • If you have a local firewall on your server (such as iptables), verify that it is not blocking your SSH and FASP transfer ports (such as TCP/UDP 33001).

Important: If you have a local firewall on your server (Windows firewall, Linux iptables, or Mac ipfw), you will need to allow the Vlink UDP port (55001, by default) for multicast traffic. For additional information on setting up Vlinks, see Setting Up Virtual Links.