tweaks

man7/ipv6.7

@@ -4,7 +4,7 @@
 .\" and in case of nontrivial modification author and date
 .\" of the modification is added to the header.
 .\" $Id: ipv6.7,v 1.3 2000/12/20 18:10:31 ak Exp $
-.TH IPV6 7 2007-10-14 "Linux" "Linux Programmer's Manual"
+.TH IPV6 7 2008-07-17 "Linux" "Linux Programmer's Manual"
 .SH NAME
 ipv6, PF_INET6 \- Linux IPv6 protocol implementation
 .SH SYNOPSIS
@@ -141,7 +141,6 @@ structure.
 .\" FIXME IPV6_CHECKSUM is not documented, and probably should be
 .\" FIXME IPV6_JOIN_ANYCAST is not documented, and probably should be
 .\" FIXME IPV6_LEAVE_ANYCAST is not documented, and probably should be
-.\" FIXME IPV6_V6ONLY is not documented, and probably should be
 .\" FIXME IPV6_RECVPKTINFO is not documented, and probably should be
 .\" FIXME IPV6_2292PKTINFO is not documented, and probably should be
 .\" FIXME there are probably many other IPV6_* socket options that
@@ -250,6 +249,23 @@ Set the unicast hop limit for the socket.
 Argument is a pointer to an integer.
 \-1 in the value means use the route default,
 otherwise it should be between 0 and 255.
+.TP
+.BR IPV6_V6ONLY " (since Linux 2.4.21 and 2.6)"
+.\" See RFC 3493
+If this flag is set to true (non-zero), then the socket is restricted
+to sending and receiving IPv6 packets only.
+In this case, an IPv4 and an IPv6 application can bind
+to a single port at the same time.
+
+If this flag is set to false (zero),
+then the socket can be used to send and receive packets
+to and from an IPv6 address or an IPv4-mapped IPv6 address.
+
+The argument is a pointer to a boolean value in an integer.
+
+The default value for this flag is defined by the contents of the file
+.BR /proc/sys/net/ipv6/bindv6only .
+The default value for that file is 0 (false).
 .\" FLOWLABEL_MGR, FLOWINFO_SEND
 .SH VERSIONS
 The older