+@c ==================================================================
+@node Signals
+@section Signals
+
+@cindex signals
+You can also send the following signals to a running tincd process:
+
+@c from the manpage
+@table @samp
+
+@item ALRM
+Forces tinc to try to connect to all uplinks immediately.
+Usually tinc attempts to do this itself,
+but increases the time it waits between the attempts each time it failed,
+and if tinc didn't succeed to connect to an uplink the first time after it started,
+it defaults to the maximum time of 15 minutes.
+
+@item HUP
+Partially rereads configuration files.
+Connections to hosts whose host config file are removed are closed.
+New outgoing connections specified in @file{tinc.conf} will be made.
+
+@item INT
+Temporarily increases debug level to 5.
+Send this signal again to revert to the original level.
+
+@item USR1
+Dumps the connection list to syslog.
+
+@item USR2
+Dumps virtual network device statistics, all known nodes, edges and subnets to syslog.
+
+@item WINCH
+Purges all information remembered about unreachable nodes.
+
+@end table
+
+@c ==================================================================
+@node Debug levels
+@section Debug levels
+
+@cindex debug levels
+The tinc daemon can send a lot of messages to the syslog.
+The higher the debug level, the more messages it will log.
+Each level inherits all messages of the previous level:
+
+@c from the manpage
+@table @samp
+
+@item 0
+This will log a message indicating tinc has started along with a version number.
+It will also log any serious error.
+
+@item 1
+This will log all connections that are made with other tinc daemons.
+
+@item 2
+This will log status and error messages from scripts and other tinc daemons.
+
+@item 3
+This will log all requests that are exchanged with other tinc daemons. These include
+authentication, key exchange and connection list updates.
+
+@item 4
+This will log a copy of everything received on the meta socket.
+
+@item 5
+This will log all network traffic over the virtual private network.
+
+@end table
+
+@c ==================================================================
+@node Solving problems
+@section Solving problems
+
+If tinc starts without problems, but if the VPN doesn't work, you will have to find the cause of the problem.
+The first thing to do is to start tinc with a high debug level in the foreground,
+so you can directly see everything tinc logs:
+
+@example
+tincd -n @var{netname} -d5 -D
+@end example
+
+If tinc does not log any error messages, then you might want to check the following things:
+
+@itemize
+@item @file{tinc-up} script
+Does this script contain the right commands?
+Normally you must give the interface the address of this host on the VPN, and the netmask must be big enough so that the entire VPN is covered.
+
+@item Subnet
+Does the Subnet (or Subnets) in the host configuration file of this host match the portion of the VPN that belongs to this host?
+
+@item Firewalls and NATs
+Do you have a firewall or a NAT device (a masquerading firewall or perhaps an ADSL router that performs masquerading)?
+If so, check that it allows TCP and UDP traffic on port 655.
+If it masquerades and the host running tinc is behind it, make sure that it forwards TCP and UDP traffic to port 655 to the host running tinc.
+You can add @samp{TCPOnly = yes} to your host config file to force tinc to only use a single TCP connection,
+this works through most firewalls and NATs.
+
+@end itemize
+