Decrement TTL of incoming packets.

[oweals/tinc.git] / doc / tinc.texi

diff --git a/doc/tinc.texi b/doc/tinc.texi
index 817c2dedcb05872ea31be34a1ad2a397c65c37b4..4b985dcd77e4240608b56b87f5128bde037e7f82 100644 (file)
--- a/doc/tinc.texi
+++ b/doc/tinc.texi
@@ -785,6 +785,13 @@ 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.
@@ -834,25 +841,25 @@ Also, in case tinc does not seem to correctly interpret packets received from th
 it can be used to change the way packets are interpreted:
 
 @table @asis
-@item tun (BSD only)
+@item tun (BSD and Linux)
 Set type to tun.
 Depending on the platform, this can either be with or without an address family header (see below).
 
 @cindex tunnohead
-@item tunnohead (BSD only)
+@item tunnohead (BSD)
 Set type to tun without an address family header.
 Tinc will expect packets read from the virtual network device to start with an IP header.
 On some platforms IPv6 packets cannot be read from or written to the device in this mode.
 
 @cindex tunifhead
-@item tunifhead (BSD only)
+@item tunifhead (BSD)
 Set type to tun with an address family header.
 Tinc will expect packets read from the virtual network device
 to start with a four byte header containing the address family,
 followed by an IP header.
 This mode should support both IPv4 and IPv6 packets.
 
-@item tap (BSD only)
+@item tap (BSD and Linux)
 Set type to tap.
 Tinc will expect packets read from the virtual network device
 to start with an Ethernet header.