Mark DecrementTTL option experimental.

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

diff --git a/doc/tinc.conf.5.in b/doc/tinc.conf.5.in
index 1d2f17f99459415c8c3862c1552176dad8e26e7b..80344183eda48a79b2b389b1dd04cf423f92af66 100644 (file)
--- a/doc/tinc.conf.5.in
+++ b/doc/tinc.conf.5.in
@@ -180,13 +180,15 @@ 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
+.It Va DecrementTTL Li = yes | no Po no Pc Bq experimental
 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.
+.Pp
+Do not use this option if you use switch mode and want to use IPv6.
 
 .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.
@@ -219,6 +221,16 @@ All packets are read from this interface.
 Packets received for the local node are written to the raw socket.
 However, at least on Linux, the operating system does not process IP packets destined for the local host.
 
+.It multicast
+Open a multicast UDP socket and bind it to the address and port (separated by spaces) and optionally a TTL value specified using
+.Va Device .
+Packets are read from and written to this multicast socket.
+This can be used to connect to UML, QEMU or KVM instances listening on the same multicast address.
+Do NOT connect multiple
+.Nm tinc 
+daemons to the same multicast address, this will very likely cause routing loops.
+Also note that this can cause decrypted VPN packets to be sent out on a real network if misconfigured.
+
 .It uml Pq not compiled in by default
 Create a UNIX socket with the filename specified by
 .Va Device ,