Decrement TTL of incoming packets.

[tinc] / doc / tinc.conf.5.in

diff --git a/doc/tinc.conf.5.in b/doc/tinc.conf.5.in
index 6853bae..8d8e6f1 100644 (file)
--- a/doc/tinc.conf.5.in
+++ b/doc/tinc.conf.5.in
@@ -168,6 +168,14 @@ If you don't specify a host with
 won't try to connect to other daemons at all,
 and will instead just listen for incoming connections.
 
+.It Va DecrementTTL Li = yes | no Po yes Pc
+When enabled,
+.Nm 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.
+
 .It Va Device Li = Ar device Po Pa /dev/tap0 , Pa /dev/net/tun No or other depending on platform Pc
 The virtual network device to use.
 .Nm tinc
@@ -222,23 +230,23 @@ it can be used to change the way packets are interpreted:
 
 .Bl -tag -width indent
 
-.It tun Pq BSD only
+.It tun Pq BSD and Linux
 Set type to tun.
 Depending on the platform, this can either be with or without an address family header (see below).
 
-.It tunnohead Pq BSD only
+.It tunnohead Pq 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.
 
-.It tunifhead Pq BSD only
+.It tunifhead Pq 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.
 
-.It tap Pq BSD only
+.It tap Pq BSD and Linux
 Set type to tap.
 Tinc will expect packets read from the virtual network device
 to start with an Ethernet header.