'\" te
.\" Copyright (c) 2008, Sun Microsystems, Inc. All Rights Reserved
.\" The contents of this file are subject to the terms of the Common Development and Distribution License (the "License").  You may not use this file except in compliance with the License.
.\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing.  See the License for the specific language governing permissions and limitations under the License.
.\" When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE.  If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
.TH IP6 7P "December 28, 2020"
.SH NAME
ip6 \- Internet Protocol Version 6
.SH SYNOPSIS
.nf
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/ip6.h>
.fi

.LP
.nf
s = socket(AF_INET6, SOCK_RAW, proto);
.fi

.LP
.nf
t = t_open ("/dev/rawip6", O_RDWR);
.fi

.SH DESCRIPTION
The \fBIPv6\fR protocol is the next generation of the internetwork datagram
delivery protocol of the Internet protocol family. Programs may use \fBIPv6\fR
through higher-level protocols such as the Transmission Control Protocol
(\fBTCP\fR) or the User Datagram Protocol (\fBUDP\fR), or may interface
directly to \fBIPv6\fR. See \fBtcp\fR(7P) and \fBudp\fR(7P). Direct access may
be by means of the socket interface, using a "raw socket," or by means of the
Transport Level Interface (\fBTLI\fR). The protocol options and \fBIPv6\fR
extension headers defined in the \fBIPv6\fR specification may be set in
outgoing datagrams.
.SH APPLICATION PROGRAMMING INTERFACE
The \fBSTREAMS\fR driver \fB/dev/rawip6\fR is the \fBTLI\fR transport provider
that provides raw access to \fBIPv6\fR.
.sp
.LP
Raw \fBIPv6\fR sockets are connectionless and are normally used with the
\fBsendto()\fR and \fBrecvfrom()\fR calls (see \fBsend\fR(3SOCKET) and
\fBrecv\fR(3SOCKET)), although the \fBconnect\fR(3SOCKET) call may also be used
to fix the destination for future datagrams. In this case, the \fBread\fR(2) or
\fBrecv\fR(3SOCKET) and \fBwrite\fR(2) or \fBsend\fR(3SOCKET) calls may be
used. Ancillary data may also be sent or received over raw \fBIPv6\fR sockets
using the \fBsendmsg\fR(3SOCKET) and \fBrecvmsg\fR(3SOCKET) system calls.
.sp
.LP
Unlike raw \fBIP\fR, \fBIPv6\fR applications do not include a complete
\fBIPv6\fR header when sending; there is no \fBIPv6\fR analog to the \fBIP\fR
\fBIP_HDRINCL\fR socket option. \fBIPv6\fR header values may be specified or
received as ancillary data to a \fBsendmsg\fR(3SOCKET) or
\fBrecvmsg\fR(3SOCKET) system call, or may be specified as "sticky" options on
a per-socket basis by using the \fBsetsockopt\fR(3SOCKET) system call. Such
sticky options are applied to all outbound packets unless overridden by
ancillary data. If any ancillary data is specified in a \fBsendmsg\fR(3SOCKET)
call, all sticky options not explicitly overridden revert to default values for
that datagram only; the sticky options persist as set for subsequent datagrams.
.sp
.LP
Since \fBsendmsg\fR(3SOCKET) is not supported for \fBSOCK_STREAM\fR upper level
protocols such as \fBTCP\fR, ancillary data is unsupported for \fBTCP\fR.
Sticky options, however, are supported.
.sp
.LP
Since \fBsendmsg\fR(3SOCKET) is supported for \fBSOCK_DGRAM\fR upper level
protocols, both ancillary data and sticky options are supported for \fBUDP\fR,
\fBICMP6\fR, and raw \fBIPv6\fR sockets.
.sp
.LP
The socket options supported at the \fBIPv6\fR level are:
.sp
.ne 2
.na
\fB\fBIPV6_BOUND_IF\fR\fR
.ad
.RS 24n
Limit reception and transmission of packets to this interface. Takes an integer
as an argument; the integer is the selected interface index.
.RE

.sp
.ne 2
.na
\fB\fBIPV6_UNSPEC_SRC\fR\fR
.ad
.RS 24n
Boolean. Allow/disallow sending with a zero source address.
.RE

.sp
.ne 2
.na
\fB\fBIPV6_UNICAST_HOPS\fR\fR
.ad
.RS 24n
Default hop limit for unicast datagrams. This option takes an integer as an
argument. Its value becomes the new default value for \fBip6_hops\fR that
\fBIPv6\fR will use on outgoing unicast datagrams sent from that socket. The
initial default is \fB60\fR.
.RE

.sp
.ne 2
.na
\fB\fBIPV6_CHECKSUM\fR\fR
.ad
.RS 24n
Specify the integer offset in bytes into the user data of the checksum
location. Does not apply to the \fBICMP6\fR protocol. Note: checksums are
required for all \fBIPv6\fR datagrams; this is different from \fBIP\fR, in
which datagram checksums were optional. \fBIPv6\fR will compute the \fBULP\fR
checksum if the value in the checksum field is zero.
.RE

.sp
.ne 2
.na
\fB\fBIPV6_SEC_OPT\fR\fR
.ad
.RS 24n
Enable or obtain IPsec security settings for this socket. For more details on
the protection services of IPsec, see \fBipsec\fR(7P).
.RE

.sp
.ne 2
.na
\fB\fBIPV6_DONTFRAG\fR\fR
.ad
.RS 24n
Boolean. Control fragmentation.
.RE

.sp
.ne 2
.na
\fB\fBIPV6_USE_MIN_MTU\fR\fR
.ad
.RS 24n
Controls whether path MTU discovery is used. If set to 1, path MTU discovery is
never used and IPv6 packets are sent with the IPv6 minimum MTU. If set to -1,
path MTU discovery is not used for multicast and multicast packets are sent
with the IPv6 minimum MTU.  If set to 0, path MTU is always performed.
.RE

.sp
.ne 2
.na
\fB\fBIPV6_V6ONLY\fR\fR
.ad
.RS 24n
Boolean. If set, only V6 packets can be sent or received
.RE

.sp
.ne 2
.na
\fB\fBIPV6_SRC_PREFERENCES\fR\fR
.ad
.RS 24n
Enable or obtain Source Address Selection rule settings for this socket. For
more details on the Source Address Selection rules, see \fBinet6\fR(7P).
.RE

.sp
.LP
The following options are boolean switches controlling the reception of
ancillary data:
.sp
.ne 2
.na
\fB\fBIPV6_RECVPKTINFO\fR\fR
.ad
.RS 25n
Enable/disable receipt of the index of the interface the packet arrived on, and
of the inbound packet's destination address.
.RE

.sp
.ne 2
.na
\fB\fBIPV6_RECVHOPLIMIT\fR\fR
.ad
.RS 25n
Enable/disable receipt of the inbound packet's current hoplimit.
.RE

.sp
.ne 2
.na
\fB\fBIPV6_RECVHOPOPTS\fR\fR
.ad
.RS 25n
Enable/disable receipt of the inbound packet's \fBIPv6\fR hop-by-hop extension
header.
.RE

.sp
.ne 2
.na
\fB\fBIPV6_RECVDSTOPTS\fR\fR
.ad
.RS 25n
Enable/disable receipt of the inbound packet's \fBIPv6\fR destination options
extension header.
.RE

.sp
.ne 2
.na
\fB\fBIPV6_RECVRTHDR\fR\fR
.ad
.RS 25n
Enable/disable receipt of the inbound packet's \fBIPv6\fR routing header.
.RE

.sp
.ne 2
.na
\fB\fBIPV6_RECVRTHDRDSTOPTS\fR\fR
.ad
.RS 25n
Enable/disable receipt of the inbound packet's intermediate-hops options
extension header. This option is obsolete. IPV6_RECVDSTOPTS turns on receipt of
both destination option headers.
.RE

.sp
.ne 2
.na
\fB\fBIPV6_RECVTCLASS\fR\fR
.ad
.RS 25n
Enable/disable receipt of the traffic class of the inbound packet.
.RE

.sp
.ne 2
.na
\fB\fBIPV6_RECVPATHMTU\fR\fR
.ad
.RS 25n
Enable/disable receipt of the path mtu of the inbound packet.
.RE

.sp
.LP
The following options may be set as sticky options with
\fBsetsockopt\fR(3SOCKET) or as ancillary data to a \fBsendmsg\fR(3SOCKET)
system call:
.sp
.ne 2
.na
\fB\fBIPV6_PKTINFO\fR\fR
.ad
.RS 21n
Set the source address and/or interface out which the packet(s) will be sent.
Takes a \fBstruct\fR \fBin6_pktinfo\fR as the parameter.
.RE

.sp
.ne 2
.na
\fB\fBIPV6_HOPLIMIT\fR\fR
.ad
.RS 21n
Set the initial hoplimit for outbound datagrams. Takes an integer as the
parameter. Note: This option sets the hoplimit only for ancillary data or
sticky options and does not change the default hoplimit for the socket; see
\fBIPV6_UNICAST_HOPS\fR and \fBIPV6_MULTICAST_HOPS\fR to change the socket's
default hoplimit.
.RE

.sp
.ne 2
.na
\fB\fBIPV6_NEXTHOP\fR\fR
.ad
.RS 21n
Specify the \fBIPv6\fR address of the first hop, which must be a neighbor of
the sending host. Takes a \fBstruct\fR \fBsockaddr_in6\fR as the parameter.
When this option specifies the same address as the destination \fBIPv6\fR
address of the datagram, this is equivalent to the existing \fBSO_DONTROUTE\fR
option.
.RE

.sp
.ne 2
.na
\fB\fBIPV6_HOPOPTS\fR\fR
.ad
.RS 21n
Specify one or more hop-by-hop options. Variable length. Takes a complete
\fBIPv6\fR hop-by-hop options extension header as the parameter.
.RE

.sp
.ne 2
.na
\fB\fBIPV6_DSTOPTS\fR\fR
.ad
.RS 21n
Specify one or more destination options. Variable length. Takes a complete
\fBIPv6\fR destination options extension header as the parameter.
.RE

.sp
.ne 2
.na
\fB\fBIPV6_RTHDR\fR\fR
.ad
.RS 21n
Specify the \fBIPv6\fR routing header. Variable length. Takes a complete
\fBIPv6\fR routing header as the parameter. Currently, only type 0 routing
headers are supported.
.RE

.sp
.ne 2
.na
\fB\fBIPV6_RTHDRDSTOPTS\fR\fR
.ad
.RS 21n
Specify one or more destination options for all intermediate hops. May be
configured, but will not be applied unless an \fBIPv6\fR routing header is also
configured. Variable length. Takes a complete \fBIPv6\fR destination options
extension header as the parameter.
.RE

.sp
.ne 2
.na
\fB\fBIPV6_PATHMTU\fR\fR
.ad
.RS 21n
Get the path MTU associated with a connected socket. Takes a ip6_mtuinfo as the
parameter.
.RE

.sp
.ne 2
.na
\fB\fBIPV6_TCLASS\fR\fR
.ad
.RS 21n
Set the traffic class associated with outgoing packets. The parameter is an
integer. If the parameter is less then -1 or greater then 256, EINVAL is
returned. If the parameter is equal to -1, use the default. If the parameter is
between 0 and 255 inclusive, use that value.
.RE

.sp
.LP
The following options affect the socket's multicast behavior:
.sp
.ne 2
.na
\fB\fBIPV6_JOIN_GROUP\fR\fR
.ad
.RS 28n
Join a multicast group. Takes a \fBstruct\fR \fBipv6_mreq\fR as the parameter;
the structure contains a multicast address and an interface index.
.RE

.sp
.ne 2
.na
\fB\fBIPV6_LEAVE_GROUP\fR\fR
.ad
.RS 28n
Leave a multicast group. Takes a \fBstruct\fR \fBipv6_mreq\fR as the parameter;
the structure contains a multicast address and an interface index.
.RE

.sp
.ne 2
.na
\fB\fBMCAST_JOIN_GROUP\fR\fR
.ad
.RS 28n
Functionally equivalent to IPV6_JOIN_GROUP. Takes a \fBstruct\fR
\fBgroup_req\fR as the parameter. The structure contains a multicast address
and an interface index.
.RE

.sp
.ne 2
.na
\fB\fBMCAST_BLOCK_SOURCE\fR\fR
.ad
.RS 28n
Block multicast packets on a particular multicast group whose source address
matches the given source address. The specified group must be joined previously
using IPV6_JOIN_GROUP or MCAST_JOIN_GROUP. Takes a \fBstruct\fR
\fBgroup_source_req\fR as the parameter. The structure contains an interface
index, a multicast address, and a source address.
.RE

.sp
.ne 2
.na
\fB\fBMCAST_UNBLOCK_SOURCE\fR\fR
.ad
.RS 28n
Unblock multicast packets which were previously blocked using
MCAST_BLOCK_SOURCE. Takes a \fBstruct\fR \fBgroup_source_req\fR as the
parameter. The structure contains an interface index, a multicast address, and
a source address.
.RE

.sp
.ne 2
.na
\fB\fBMCAST_LEAVE_GROUP\fR\fR
.ad
.RS 28n
Functionally equivalent to IPV6_LEAVE_GROUP. Takes a \fBstruct\fR
\fBgroup_req\fR as the parameter. The structure contains a multicast address
and an interface index.
.RE

.sp
.ne 2
.na
\fB\fBMCAST_JOIN_SOURCE_GROUP\fR\fR
.ad
.RS 28n
Begin receiving packets for the given multicast group whose source address
matches the specified address. Takes a \fBstruct\fR \fBgroup_source_req\fR as
the parameter. The structure contains an interface index, a multicast address,
and a source address.
.RE

.sp
.ne 2
.na
\fB\fBMCAST_LEAVE_SOURCE_GROUP\fR\fR
.ad
.RS 28n
Stop receiving packets for the given multicast group whose source address
matches the specified address. Takes a \fBstruct\fR \fBgroup_source_req\fR as
the parameter. The structure contains an interface index, a multicast address,
and a source address.
.RE

.sp
.ne 2
.na
\fB\fBIPV6_MULTICAST_IF\fR\fR
.ad
.RS 28n
The outgoing interface for multicast packets. This option takes an integer as
an argument; the integer is the interface index of the selected interface.
.RE

.sp
.ne 2
.na
\fB\fBIPV6_MULTICAST_HOPS\fR\fR
.ad
.RS 28n
Default hop limit for multicast datagrams. This option takes an integer as an
argument. Its value becomes the new default value for \fBip6_hops\fR that
\fBIPv6\fR will use on outgoing multicast datagrams sent from that socket. The
initial default is \fB1\fR.
.RE

.sp
.ne 2
.na
\fB\fBIPV6_MULTICAST_LOOP\fR\fR
.ad
.RS 28n
Loopback for multicast datagrams. Normally multicast datagrams are delivered to
members on the sending host. Setting the unsigned character argument to 0 will
cause the opposite behavior.
.RE

.sp
.LP
The multicast socket options can be used with any datagram socket type in the
\fBIPv6\fR family.
.sp
.LP
At the socket level, the socket option \fBSO_DONTROUTE\fR may be applied. This
option forces datagrams being sent to bypass routing and forwarding by forcing
the \fBIPv6\fR hoplimit field to \fB1\fR, meaning that the packet will not be
forwarded by routers.
.sp
.LP
Raw \fBIPv6\fR datagrams can also be sent and received using the \fBTLI\fR
connectionless primitives.
.sp
.LP
Datagrams flow through the \fBIPv6\fR layer in two directions: from the network
\fIup\fR to user processes and from user processes \fIdown\fR to the network.
Using this orientation, \fBIPv6\fR is layered \fIabove\fR the network interface
drivers and \fIbelow\fR the transport protocols such as \fBUDP\fR and
\fBTCP\fR. The Internet Control Message Protocol (\fBICMPv6\fR) for the
Internet Protocol Version 6 (\fBIPv6\fR) is logically a part of \fBIPv6\fR. See
\fBicmp6\fR(7P).
.sp
.LP
Unlike \fBIP\fR, \fBIPv6\fR provides no checksum of the \fBIPv6\fR header. Also
unlike \fBIP\fR, upper level protocol checksums are required. \fBIPv6\fR will
compute the \fBULP\fR/data portion checksum if the checksum field contains a
zero (see \fBIPV6_CHECKSUM\fR option above).
.sp
.LP
\fBIPv6\fR extension headers in received datagrams are processed in the
\fBIPv6\fR layer according to the protocol specification. Currently recognized
\fBIPv6\fR extension headers include hop-by-hop options header, destination
options header, routing header (currently, only type 0 routing headers are
supported), and fragment header.
.sp
.LP
By default, the IPv6 layer will not forward IPv6 packets that are not addressed
to it. This behavior can be overridden by using  \fBrouteadm\fR(1M) to enable
the ipv6-forwarding option. IPv6 forwarding is configured at boot time based on
the setting of \fBrouteadm\fR(1M)'s ipv6-forwarding option.
.sp
.LP
For backwards compatibility, IPv6 forwarding can be enabled or disabled using
\fBndd\fR(1M)'s ip_forwarding variable.  It is set to 1 if IPv6 forwarding is
enabled, or 0 if it is disabled.
.sp
.LP
Additionally, finer-grained forwarding can be configured in IPv6. Each
interface can be configured to forward IPv6 packets by setting the IFF_ROUTER
interface flag. This flag can be set and cleared using \fBifconfig\fR(1M)'s
router and -router options. If an interface's IFF_ROUTER flag is set, packets
can be forwarded to or from the interface. If it is clear, packets will neither
be forwarded from this interface to others, nor forwarded to this interface.
Setting the ip6_forwarding variable sets all of the IPv6 interfaces' IFF_ROUTER
flags.
.sp
.LP
For backwards compatibility, each interface creates an
\fB<ifname>ip6_forwarding /dev/ip6\fR variable that can be modified using
\fBndd\fR(1M). An interface's \fB:ip6_forwarding ndd\fR variable is a boolean
variable that mirrors the status of its IFF_ROUTER interface flag. It is set to
1 if the flag is set, or 0 if it is clear. This interface specific
\fB<ifname>:ip6_forwarding ndd\fR variable is obsolete and may be removed in a
future release of Solaris. The \fBifconfig\fR(1M) router and -router interfaces
are preferred.
.sp
.LP
The \fBIPv6\fR layer will send an \fBICMP6\fR message back to the source host
in many cases when it receives a datagram that can not be handled. A
"\fBtime\fR \fBexceeded\fR" \fBICMP6\fR message will be sent if the
\fBip6_hops\fR field in the \fBIPv6\fR header drops to zero in the process of
forwarding a datagram. A "\fBdestination\fR \fBunreachable\fR" message will be
sent by a router or by the originating host if a datagram can not be sent on
because there is no route to the final destination; it will be sent by a router
when it encounters a firewall prohibition; it will be sent by a destination
node when the transport protocol (that is, \fBTCP\fR) has no listener. A
"\fBpacket\fR \fBtoo\fR \fBbig\fR" message will be sent by a router if the
packet is larger than the \fBMTU\fR of the outgoing link (this is used for Path
\fBMTU\fR Discovery). A "\fBparameter\fR \fBproblem\fR" message will be sent if
there is a problem with a field in the \fBIPv6\fR header or any of the
\fBIPv6\fR extension headers such that the packet cannot be fully processed.
.sp
.LP
The \fBIPv6\fR layer supports fragmentation and reassembly. Datagrams are
fragmented on output if the datagram is larger than the maximum transmission
unit (\fBMTU\fR) of the network interface. Fragments of received datagrams are
dropped from the reassembly queues if the complete datagram is not
reconstructed within a short time period.
.sp
.LP
Errors in sending discovered at the network interface driver layer are passed
by IPv6 back up to the user process.
.SH SEE ALSO
\fBsvcs\fR(1), \fBndd\fR(1M), \fBrouteadm\fR(1M), \fBsvcadm\fR(1M),
\fBread\fR(2), \fBwrite\fR(2), \fBbind\fR(3SOCKET), \fBconnect\fR(3SOCKET),
\fBgetsockopt\fR(3SOCKET), \fBrecv\fR(3SOCKET), \fBrecvmsg\fR(3SOCKET),
\fBsend\fR(3SOCKET), \fBsendmsg\fR(3SOCKET), \fBsetsockopt\fR(3SOCKET),
\fBdefaultrouter\fR(4), \fBsmf\fR(5), \fBicmp6\fR(7P), \fBif_tcp\fR(7P),
\fBipsec\fR(7P), \fBinet6\fR(7P), \fBrouting\fR(7P), \fBtcp\fR(7P),
\fBudp\fR(7P)
.sp
.LP
Deering, S. and Hinden, B. \fI RFC 2460, Internet Protocol, Version 6 (IPv6)
Specification\fR. The Internet Society. December, 1998.
.sp
.LP
Stevens, W., and Thomas, M. \fIRFC 2292, Advanced Sockets API for IPv6\fR.
Network Working Group. February 1998.
.SH DIAGNOSTICS
A socket operation may fail with one of the following errors returned:
.sp
.ne 2
.na
\fB\fBEPROTONOSUPPORT\fR\fR
.ad
.RS 19n
Unsupported protocol (for example, IPPROTO_RAW.)
.RE

.sp
.ne 2
.na
\fB\fBEACCES\fR\fR
.ad
.RS 19n
A \fBbind()\fR operation was attempted with a "reserved" port number and the
effective user ID of the process was not the privileged user.
.RE

.sp
.ne 2
.na
\fB\fBEADDRINUSE\fR\fR
.ad
.RS 19n
A \fBbind()\fR operation was attempted on a socket with a network address/port
pair that has already been bound to another socket.
.RE

.sp
.ne 2
.na
\fB\fBEADDRNOTAVAIL\fR\fR
.ad
.RS 19n
A \fBbind()\fR operation was attempted for an address that is not configured on
this machine.
.RE

.sp
.ne 2
.na
\fB\fBEINVAL\fR\fR
.ad
.RS 19n
A \fBsendmsg()\fR operation with a non-NULL \fBmsg_accrights\fR was attempted.
.RE

.sp
.ne 2
.na
\fB\fBEINVAL\fR\fR
.ad
.RS 19n
A \fBgetsockopt()\fR or \fBsetsockopt()\fR operation with an unknown socket
option name was given.
.RE

.sp
.ne 2
.na
\fB\fBEINVAL\fR\fR
.ad
.RS 19n
A \fBgetsockopt()\fR or \fBsetsockopt()\fR operation was attempted with the
\fBIPv6\fR option field improperly formed; an option field was shorter than the
minimum value or longer than the option buffer provided; the value in the
option field was invalid.
.RE

.sp
.ne 2
.na
\fB\fBEISCONN\fR\fR
.ad
.RS 19n
A \fBconnect()\fR operation was attempted on a socket on which a
\fBconnect()\fR operation had already been performed, and the socket could not
be successfully disconnected before making the new connection.
.RE

.sp
.ne 2
.na
\fB\fBEISCONN\fR\fR
.ad
.RS 19n
A \fBsendto()\fR or \fBsendmsg()\fR operation specifying an address to which
the message should be sent was attempted on a socket on which a \fBconnect()\fR
operation had already been performed.
.RE

.sp
.ne 2
.na
\fB\fBEMSGSIZE\fR\fR
.ad
.RS 19n
A \fBsend()\fR, \fBsendto()\fR, or \fBsendmsg()\fR operation was attempted to
send a datagram that was too large for an interface, but was not allowed to be
fragmented (such as broadcasts).
.RE

.sp
.ne 2
.na
\fB\fBENETUNREACH\fR\fR
.ad
.RS 19n
An attempt was made to establish a connection via \fBconnect()\fR, or to send a
datagram by means of \fBsendto()\fR or \fBsendmsg()\fR, where there was no
matching entry in the routing table; or if an \fBICMP\fR "\fBdestination
unreachable\fR" message was received.
.RE

.sp
.ne 2
.na
\fB\fBENOTCONN\fR\fR
.ad
.RS 19n
A \fBsend()\fR or \fBwrite()\fR operation, or a \fBsendto()\fR or
\fBsendmsg()\fR operation not specifying an address to which the message should
be sent, was attempted on a socket on which a \fBconnect()\fR operation had not
already been performed.
.RE

.sp
.ne 2
.na
\fB\fBENOBUFS\fR\fR
.ad
.RS 19n
The system ran out of memory for fragmentation buffers or other internal data
structures.
.RE

.sp
.ne 2
.na
\fB\fBENOMEM\fR\fR
.ad
.RS 19n
The system was unable to allocate memory for an \fBIPv6\fR socket option or
other internal data structures.
.RE

.sp
.ne 2
.na
\fB\fBENOPROTOOPT\fR\fR
.ad
.RS 19n
An \fBIP\fR socket option was attempted on an \fBIPv6\fR socket, or an
\fBIPv6\fR socket option was attempted on an \fBIP\fR socket.
.RE

.sp
.ne 2
.na
\fB\fBENOPROTOOPT\fR\fR
.ad
.RS 19n
Invalid socket type for the option.
.RE

.SH NOTES
Applications using the sockets \fBAPI\fR must use the Advanced Sockets
\fBAPI\fR for \fBIPv6\fR (\fIRFC 2292\fR) to see elements of the inbound
packet's \fBIPv6\fR header or extension headers.
.sp
.LP
The \fBip6\fR service is managed by the service management facility,
\fBsmf\fR(5), under the service identifier:
.sp
.in +2
.nf
svc:/network/initial:default
.fi
.in -2
.sp

.sp
.LP
Administrative actions on this service, such as enabling, disabling, or
requesting restart, can be performed using \fBsvcadm\fR(1M). The service's
status can be queried using the \fBsvcs\fR(1) command.