The Serv-U file server offers a highly configurable interface for enabling the different file sharing protocols on a domain. You can add, edit, and delete listeners.
Each domain can listen on multiple ports and IP addresses by adding a listener bound to the IP address and port you want. In addition to selecting these connection attributes for a listener, you must also select a file sharing protocol. Serv-U supports IPv4 and IPv6 simultaneously.
To offer services to both IPv4 and IPv6 users, create a listener both for an IPv4 address and an IPv6 address. The following section contains the list and short description of the file sharing protocols supported by the Serv-U File Server.
All Serv-U versions with supported OS:
Adding a listener
After clicking Add, the listener configuration window is displayed. After configuring each of the listener options, click Save to add the listener to the domain. The following section contains the list and short description of the options you can configure for a listener.
Select the file sharing protocol that is to be supported by this listener. Each listener can only support a single protocol. To add more file sharing protocols to the domain, create new listeners for each protocol. A brief description of the supported file sharing protocols is found in the previous section.
You can bind a listener to a single IP address by entering the IP address here. Serv-U supports both IPv4 and IPv6 addresses. If the file server does not have an external IP address (for example, it is behind a router), you can leave this field blank. If you do not specify an IP address, you must select the option to either listen on all available IPv4 addresses or all IPv6 addresses. Unless you are running a purely IPv6 network, it is recommended to use IPv4 addresses and add IPv6 listeners as needed.
If you want to add a listener that will listen to the internal network and not with the Serv-U gateway that is on a DMZ, you just need to add a listener with the Serv-U MFT IP Address. This listener can only be access from the inside.
PASV IP Address or Domain Name (FTP ONLY)
If the listener supports the FTP protocol, this additional field is available where you can specify a separate IP address to use for PASV mode data transfers. Entering an IP address here ensures that PASV mode works properly on both unsecured and secured connections. If the file server does not have an external IP address, try using a dynamic DNS service and entering your DNS domain name in this field. Serv-U resolves the DNS domain name to ensure it always has the proper external IP address for PASV command responses.
Use only with SSL connections
This option allows the PASV IP address or domain name to only be used for SSL connections where it is always necessary to provide the PASV IP address to connecting clients. When this option is enabled, the IP address specified for PASV mode will not be provided to clients connecting through non-SSL FTP.
Use with LAN connections
Normally, Serv-U does not use the PASV IP address for connections coming from the local area network (computers on the same network as Serv-U). When this option is enabled, the PASV IP Address is also used for LAN connections
The default port for the selected protocol is automatically provided. However, you can use any port between 1 and 65535. When using a nonstandard port, clients must know the proper port in advance when they attempt to connect to the domain. If you use a non-standard port, it is recommended that you use a value above 1024 to prevent potential conflicts.
You can temporarily disable a listener by deselecting this option. When they are disabled, listeners are displayed with a different icon in the list.