IPv6 RAW applications can get or set selected IP header information for incoming and outgoing datagrams by way of socket options and ancillary data as follows:

• Applications can set the IPV6_RECVHOPLIMIT socket option in order to get the hop limit for incoming datagrams in ancillary data. By default, this socket option is set to off.
• Applications can set the IPV6_RECVPKTINFO socket option in order to get the destination IP address and interface identifier for incoming datagrams in ancillary data. By default, this socket option is set to off.
• Applications can set the IPV6_RECVRTHDR socket option in order to get the routing header for incoming datagrams in ancillary data. By default, this socket option is set to off.
• Applications can set the IPV6_RECVHOPOPTS socket option in order to get the hop-by-hop options for incoming datagrams in ancillary data. By default, this socket option is set to off.
• Applications can set the IPV6_RECVDSTOPTS socket option in order to get the destination options for incoming datagrams in ancillary data. By default, this socket option is set to off.
• Applications can set the IPV6_RECVTCLASS socket option in order to get the traffic class for incoming datagrams in ancillary data. By default, this socket option is set to off.
• Applications can set the IPV6_UNICAST_HOPS socket option in order to set the hop limit for outgoing unicast datagrams. By default, this socket option is set to off and the configured maximum hop limit or the default hop limit is used.
• Applications can set the IPV6_MULTICAST_HOPS socket option in order to set the hop limit for outgoing multicast datagrams. By default, this socket option is set to off and a hop limit of 1 is used.
• Applications can use the IPV6_HOPLIMIT ancillary data option to set the hop limit for an outgoing datagram.
• Applications can use the IPV6_PKTINFO socket option and ancillary data option to set the source address and interface identifier for outgoing datagrams. By default, the socket option is set to off.
• Applications can use the IPV6_NEXTHOP socket option and ancillary data option to set the next hop address for outgoing datagrams. By default, the socket option is set to off.
• Applications can use the IPV6_RTHDR socket option and ancillary data option to set the routing header for outgoing datagrams. By default, the socket option is set to off.
• Applications can use the IPV6_HOPOPTS socket option and ancillary data option to set the hop-by-hop options for outgoing datagrams. By default, the socket option is set to off.
• Applications can use the IPV6_DSTOPTS socket option and ancillary data option to set the destination options (that get examined by the host at the final destination) for outgoing datagrams. By default, the socket option is set to off.
• Applications can use the IPV6_RTHDRDSTOPTS socket option and ancillary data option to set the destination options (that get examined by every host that appears in the routing header) for outgoing datagrams. By default, the socket option is set to off.
• Applications can use the IPV6_TCLASS socket option and ancillary data option to set the traffic class for outgoing datagrams. By default, the socket option is set to off.