How To Configure A Server¶
Many Tahoe-LAFS nodes run as “servers”, meaning they provide services for other machines (i.e. “clients”). The two most important kinds are the Introducer, and Storage Servers.
To be useful, servers must be reachable by clients. Tahoe servers can listen on TCP ports, and advertise their “location” (hostname and TCP port number) so clients can connect to them. They can also listen on Tor “onion services” and I2P ports.
Storage servers advertise their location by announcing it to the Introducer, which then broadcasts the location to all clients. So once the location is determined, you don’t need to do anything special to deliver it.
The Introducer itself has a location, which must be manually delivered to all
storage servers and clients. You might email it to the new members of your
grid. This location (along with other important cryptographic identifiers) is
written into a file named
private/introducer.furl in the Introducer’s
base directory, and should be provided as the
--introducer= argument to
tahoe create-client or
The first step when setting up a server is to figure out how clients will reach it. Then you need to configure the server to listen on some ports, and then configure the location properly.
Each server has two settings in their
tub.location. The “port” controls what the server node listens to: this
is generally a TCP port.
The “location” controls what is advertised to the outside world. This is a
“foolscap connection hint”, and it includes both the type of the connection
(tcp, tor, or i2p) and the connection details (hostname/address, port
number). Various proxies, port-forwardings, and privacy networks might be
involved, so it’s not uncommon for
tub.location to look
You can directly control the
settings by providing
--location= when running
Instead of providing
--port=/--location=, you can use
Servers can listen on TCP, Tor, I2P, a combination of those, or none at all.
--listen= argument controls which kinds of listeners the new server
--listen=none means the server should not listen at all. This doesn’t
make sense for a server, but is appropriate for a client-only node. The
tahoe create-client command automatically includes
--listen=tcp is the default, and turns on a standard TCP listening port.
--listen=tcp requires a
--hostname= argument too, which will be
incorporated into the node’s advertised location. We’ve found that computers
cannot reliably determine their externally-reachable hostname, so rather than
having the server make a guess (or scanning its interfaces for IP addresses
that might or might not be appropriate), node creation requires the user to
provide the hostname.
--listen=tor will talk to a local Tor daemon and create a new “onion
server” address (which look like
--listen=i2p will talk to a local I2P daemon and create a new server
address. See Using Tahoe-LAFS with an anonymizing network: Tor, I2P for details.
You could listen on all three by using
The following are some suggested scenarios for configuring servers using various network transports. These examples do not include specifying an introducer FURL which normally you would want when provisioning storage nodes. For these and other configuration details please refer to Configuring a Tahoe-LAFS node.
Server has a public DNS name¶
The simplest case is where your server host is directly connected to the internet, without a firewall or NAT box in the way. Most VPS (Virtual Private Server) and colocated servers are like this, although some providers block many inbound ports by default.
For these servers, all you need to know is the external hostname. The system administrator will tell you this. The main requirement is that this hostname can be looked up in DNS, and it will map to an IPv4 or IPv6 address which will reach the machine.
If your hostname is
example.net, then you’ll create the introducer like
tahoe create-introducer --hostname example.com ~/introducer
or a storage server like:
tahoe create-node --hostname=example.net
These will allocate a TCP port (e.g. 12345), assign
tub.port to be
tub.location will be
Ideally this should work for IPv6-capable hosts too (where the DNS name provides an “AAAA” record, or both “A” and “AAAA”). However Tahoe-LAFS support for IPv6 is new, and may still have problems. Please see ticket #867 for details.
Server has a public IPv4/IPv6 address¶
If the host has a routeable (public) IPv4 address (e.g.
no DNS name, you will need to choose a TCP port (e.g.
3457), and use the
tahoe create-node --port=tcp:3457 --location=tcp:203.0.113.1:3457
--port is an “endpoint specification string” that controls which local
port the node listens on.
--location is the “connection hint” that it
advertises to others, and describes the outbound connections that those
clients will make, so it needs to work from their location on the network.
Tahoe-LAFS nodes listen on all interfaces by default. When the host is
multi-homed, you might want to make the listening port bind to just one
specific interface by adding a
interface= option to the
tahoe create-node --port=tcp:3457:interface=203.0.113.1 --location=tcp:203.0.113.1:3457
If the host’s public address is IPv6 instead of IPv4, use square brackets to
wrap the address, and change the endpoint type to
tahoe create-node --port=tcp6:3457 --location=tcp:[2001:db8::1]:3457
You can use
interface= to bind to a specific IPv6 interface too, however
you must backslash-escape the colons, because otherwise they are interpreted
as delimiters by the Twisted “endpoint” specification language. The
--location= argument does not need colons to be escaped, because they are
wrapped by the square brackets:
tahoe create-node --port=tcp6:3457:interface=2001\:db8\:\:1 --location=tcp:[2001:db8::1]:3457
For IPv6-only hosts with AAAA DNS records, if the simple
configuration does not work, they can be told to listen specifically on an
IPv6-enabled port with this:
tahoe create-node --port=tcp6:3457 --location=tcp:example.net:3457
Server is behind a firewall with port forwarding¶
To configure a storage node behind a firewall with port forwarding you will need to know:
public IPv4 address of the router
the TCP port that is available from outside your network
the TCP port that is the forwarding destination
internal IPv4 address of the storage node (the storage node itself is unaware of this address, and it is not used during
tahoe create-node, but the firewall must be configured to send connections to this)
The internal and external TCP port numbers could be the same or different depending on how the port forwarding is configured. If it is mapping ports 1-to-1, and the public IPv4 address of the firewall is 203.0.113.1 (and perhaps the internal IPv4 address of the storage node is 192.168.1.5), then use a CLI command like this:
tahoe create-node --port=tcp:3457 --location=tcp:203.0.113.1:3457
If however the firewall/NAT-box forwards external port 6656 to internal port 3457, then do this:
tahoe create-node --port=tcp:3457 --location=tcp:203.0.113.1:6656
Using I2P/Tor to Avoid Port-Forwarding¶
I2P and Tor onion services, among other great properties, also provide NAT penetration without port-forwarding, hostnames, or IP addresses. So setting up a server that listens only on Tor is simple:
tahoe create-node --listen=tor
For more information about using Tahoe-LAFS with I2p and Tor see Using Tahoe-LAFS with an anonymizing network: Tor, I2P