Running a gnunet-nat-server is similar to running a hostlist server: it is a special service to the
community with special requirements and no benefit to those running the service.
This program will listen on the specified PORT for incoming requests to test a peer's network
connectivity. Incoming requests can ask it to connect to a given IPv4 address (and port) using TCP or
UDP and to send a 2-byte test message using the specified address. The program can also be asked to send
a "fake" ICMP response message to a given IPv4 address (for autonomous NAT traversal --- see the
description in the respective research paper).
The idea is that gnunet-nat-server will be run on some trusted hosts with unrestricted connectivity to
allow GNUnet users to test their network configuration. As written, the code allows any user on the
Internet to cause the gnunet-nat-server to send 2-bytes of arbitrary data to any TCP or UDP port at any
address. We believe that this is generally harmless.
When running gnunet-nat-server, make sure to use a configuration that disables most NAT options but
enables 'enable_nat_client' and sets 'internal_address' to the global IP address of your local host.
Also, the gnunet-helper-nat-client should be installed locally and run with root privileges (SUID),
otherwise the gnunet-nat-server will not work properly.
Note that gnunet-nat-server could be run via gnunet-arm but typically is not. Also, the name of the host
and port that gnunet-nat-server is run on should be specified in the NATSERVER option in the [setup]
section of the configuration file of hosts that are supposed to autoconfigure with this server.
Normal GNUnet end-users should not concern themselves with gnunet-nat-server. In fact, distributions are
encouraged to consider not shipping it at all.
The options are as follows:
-cFILENAME | --config=FILENAME
Use the configuration file FILENAME.
-d | --daemonize
Daemonize gnunet-nat-server (detach from terminal).
-h | --help
Print the help page.
-LLOGLEVEL | --log=LOGLEVEL
Configure logging to use LOGLEVEL.
-lFILENAME | --logfile=FILENAME
Configure logging to write logs to FILENAME.
-v | --version
Print the GNUnet version.