actions were applied.
.
.IP \fBdec_ttl\fR
+.IQ \fBdec_ttl\fB[\fR(\fIid1,id2\fI)\fR]\fR
Decrement TTL of IPv4 packet or hop limit of IPv6 packet. If the
TTL or hop limit is initially zero, no decrement occurs. Instead,
a ``packet-in'' message with reason code \fBOFPR_INVALID_TTL\fR is
sent to each connected controller that has enabled receiving them,
-if any. Processing the current set of actions then stops.
-However, if the current set of actions was reached through
-``resubmit'' then remaining actions in outer levels resume
-processing.
+if any. Processing the current set of actions then stops. However,
+if the current set of actions was reached through ``resubmit'' then
+remaining actions in outer levels resume processing. This action
+also optionally supports the ability to specify a list of valid
+controller ids. Each of controllers in the list will receive the
+``packet_in'' message only if they have registered to receive the
+invalid ttl packets. If controller ids are not specified, the
+``packet_in'' message will be sent only to the controllers having
+controller id zero which have registered for the invalid ttl packets.
.
.IP \fBnote:\fR[\fIhh\fR]...
Does nothing at all. Any number of bytes represented as hex digits