Use these settings to manually configure DC++ for incoming connections. If
unsure about these settings, you may want to follow the Manual
connection setup guide. While some settings as various Ports are
shared, the rest are grouped making possible to individually set and fine
tune connectivity for IPv4 and IPv6 protocols. Settings on this pane are
unavailabe and ignored when Automatic connectivity setup is
enabled. Note that IPv6 support is currently in experimental state and DC++
might not able to connect to all kinds of DC clients using the IPv6
Before changing these make sure you are familiar with the meaning of each
connection mode and with the differences between active and
passive mode and their effect on your ability to search and download from
users of the DC network.
Manual incoming connection settings for both IPv4 and IPv6 protocols
These settings specify the communication ports DC++ listens on for incoming
connections. Generally you don't need to add specific ports unless you
configured your port forwarding settings manually. If port settings are left
blank, DC++ will let the operating system generate a random port
number. Port values are ignored when Automatic connectivity
setup is enabled.
- Transfer port (TCP)
- This is the port that DC++ listens on for incoming connections from other
peers. If this port is incorrectly forwarded, you won't be able to download.
- Encrypted transfer port (TCP)
- This is the port that DC++ listens on for incoming TLS
(encrypted) connections from other peers. If this port is incorrectly
forwarded, you won't be able to search nor to download on encrypted ADC
hubs. Note that this port value should be different than the one used for
- Search port (UDP)
- This is the port that DC++ listens on for incoming search results. If this
port is incorrectly forwarded, you won't be able to receive search results.
Individual settings for IPv4 and IPv6 protocols
The following incoming connection settings grouped to be able to do a
separate setup for the two available IP protocols.
- Active mode (I have no router / I have configured my router)
Select this mode if you are directly connected to the Internet (no router)
or if you are willing to manually configure port forwarding rules in your
router. Use this mode only if the automatic configuration (via NAT-PMP /
UPnP) is not an option for you. For more information, refer to the Manual port forwarding guide.
- Active mode (let DC++ configure my router with NAT-PMP / UPnP)
Select this mode if you are behind a router that supports standard port
forwarding methods such as NAT-PMP or UPnP. Most routers do support them but
they often have to be explicitly enabled from the router's configuration
page. Thanks to automatic port mapping methods, DC++ is able to open the
ports it needs and obtain your external IP address as well. For more
information, see What is NAT-PMP / UPnP?.
- Passive mode (last resort - has serious limitations)
Select this mode if you can't get active mode to work. In this mode, DC++
will not try to listen for inbound connections; it will only initiate
outbound ones. This mode carries some serious limitations:
Note that DC++ tries NAT Traversal on ADC hubs to allow passive users to
connect with each other.
- only 5 results per user will be returned in response to searches.
- you may not be able to download / receive search results from passive users.
- you may not be able to fully enjoy certain hubs (because of their
- Disable connectivity
Select this mode if you do not wish to have the specified protocol active.
- External / WAN IP address
These fields specify your external IP addresses for the specified protocol.
Note: most hubs are able to determine your external IPs and forward it to
your DC++, making a manual configuration of this field unnecessary. If
your computer is directly connected to the internet, your internal and
external IP will be the same and can easily be automatically detected. Fill
these boxes only if you need to override said auto-detection.
Ordinarily, only users behind a router (NAT device) need to fill in this
boxes. If you put a DNS name here, DC++ will try to resolve it into an IP
address before use. For additional information like how to determine your
external IP address, follow the Manual connection setup
- Don't allow hubs/NAT-PMP/UPnP to override
Enable this to always use the IP address in "External / WAN IP", and not let
either NAT-PMP, UPnP nor connected hubs change it. If unsure, leave this
- Preferred port mapping interface
DC++ has several interfaces available it can use to try to automatically map
the ports it requires on the router:
The interface selected here will be tried first; other available interfaces
will then be tried if the preferred port mapping interface were to fail.
- NAT-PMP: A lightweight protocol that is not widely used by generic routers;
but open-source firmwares generally implement it.
- MiniUPnP: An open-source UPnP library.
- Bind Address
This setting allows binding DC++ network connections of the specified
protocol to a specific network adapter by its IP address. Useful when you
have more than one physical or virtual network adapter installed and you
want to assign a specfic device for all the network traffic generated for a
certain IP protocol by DC++.
If this setting is set to 'Default' it means that DC++ is relying on the
operating system to find the best adapter. In case of the adapter offered by
the operating system does not suit you, you can override it here by
selecting the required adapter.
If binding with the selected adapter fails, it will do so silently and the
'Default' setting (INADDR_ANY) will be used instead.