Add LocalDiscovery option which tries to detect peers on the local network.

[tinc] / doc / tinc.texi

diff --git a/doc/tinc.texi b/doc/tinc.texi
index 3bb4407..0697f10 100644 (file)
--- a/doc/tinc.texi
+++ b/doc/tinc.texi
@@ -773,6 +773,10 @@ variable.
 
 This option may not work on all platforms.
 
+@cindex Broadcast
+@item Broadcast = <yes | no> (yes) [experimental]
+When disabled, tinc will drop all broadcast and multicast packets, in both router and switch mode.
+
 @cindex ConnectTo
 @item ConnectTo = <@var{name}>
 Specifies which other tinc daemon to connect to on startup.
@@ -785,6 +789,13 @@ If you don't specify a host with ConnectTo,
 tinc won't try to connect to other daemons at all,
 and will instead just listen for incoming connections.
 
+@cindex DecrementTTL
+@item DecrementTTL = <yes | no> (yes)
+When enabled, tinc will decrement the Time To Live field in IPv4 packets, or the Hop Limit field in IPv6 packets,
+before forwarding a received packet to the virtual network device or to another node,
+and will drop packets that have a TTL value of zero,
+in which case it will send an ICMP Time Exceeded packet back.
+
 @cindex Device
 @item Device = <@var{device}> (@file{/dev/tap0}, @file{/dev/net/tun} or other depending on platform)
 The virtual network device to use.
@@ -912,6 +923,16 @@ Depending on the operating system and the type of device this may or may not act
 Under Windows, this variable is used to select which network interface will be used.
 If you specified a Device, this variable is almost always already correctly set.
 
+@cindex LocalDiscovery
+@item LocalDiscovery = <yes | no> (no) [experimental]
+When enabled, tinc will try to detect peers that are on the same local network.
+This will allow direct communication using LAN addresses, even if both peers are behind a NAT
+and they only ConnectTo a third node outside the NAT,
+which normally would prevent the peers from learning each other's LAN address.
+
+Currently, local discovery is implemented by sending broadcast packets to the LAN during path MTU discovery.
+This feature may not work in all possible situations.
+
 @cindex Mode
 @item Mode = <router|switch|hub> (router)
 This option selects the way packets are routed to other daemons.
@@ -1610,6 +1631,12 @@ Generate public/private keypair of @var{bits} length. If @var{bits} is not speci
 but will default to the configuration directory (you can use the -c or -n option
 in combination with -K). After that, tinc will quit.
 
+@item -o, --option=[@var{HOST}.]@var{KEY}=@var{VALUE}
+Without specifying a @var{HOST}, this will set server configuration variable @var{KEY} to @var{VALUE}.
+If specified as @var{HOST}.@var{KEY}=@var{VALUE},
+this will set the host configuration variable @var{KEY} of the host named @var{HOST} to @var{VALUE}.
+This option can be used more than once to specify multiple configuration variables.
+
 @item -L, --mlock
 Lock tinc into main memory.
 This will prevent sensitive data like shared private keys to be written to the system swap files/partitions.