Let a user pick their cluster's own multicast group

1 files changed, 15 insertions, 7 deletions

diff --git a/opentracker.conf.sample b/opentracker.conf.sample
index 3cd30dc..7b35369 100644
--- a/opentracker.conf.sample
+++ b/opentracker.conf.sample
@@ -138,14 +138,22 @@
 # livesync.cluster.listen 192.168.0.1:9696
 #
 #      Note that two udp sockets will be opened. One on ip address 0.0.0.0
-#      port 9696, that will join the multicast group 224.0.23.5 for incoming
-#      udp packets and one on ip address 192.168.0.1 port 9696 for outgoing
-#      udp packets. The group is the same for every opentracker, so a cluster
-#      is kept to itself by the node_ip list below and by the ttl of 1 that
-#      keeps packets on the local link.
+#      port 9696, that will join the multicast group for incoming udp packets
+#      and one on ip address 192.168.0.1 port 9696 for outgoing ones. Every
+#      member of a cluster has to agree on the port as well as the group.
+#
+#      The group a cluster talks in.
+#
+# livesync.cluster.group 239.192.23.5
+#
+#      For reaosns of backwards comaptibility with legacy trackers, it
+#      defaults to 224.0.23.5, which, technically sits in a range IANA
+#      assigns on request.
+#
+#      A cluster of your own is better served by an address out of
+#      239.192.0.0/14, which RFC 2365 sets aside for private use. Packets
+#      carry a ttl of 1 either way, so they never leave the local link.
 #
-#      As of now one and only one ip address must be given, if opentracker
-#      was built with the WANT_SYNC_LIVE feature.
 #
 
 # IV)  Sync between trackers running in a cluster is restricted to packets