3.5.10. BindV6Only Previous topic Parent topic Child topic Next topic

This optional parameter allows you to explicitly set the IPV6_V6ONLY option for the sockets listening to IPv6 wildcard address.
RFC 3493 “Basic Socket Interface Extensions for IPv6” specifies a boolean socket option IPV6_V6ONLY. When this option is turned off, IPv6 wildcard listen socket can receive both IPv6 and IPv4 packets. Received IPv4 packets use special IPv4-mapped address format where the IPv4 address is encoded after the 96-bit prefix 0:0:0:0:FFFF.
For example, request from IPv4 address 172.16.172.2 is mapped to IPv6 address ::ffff:172.16.172.2. In this case you may need to configure your Client clause as <Client ::ffff:172.16.172.2>
IPV6_V6ONLY socket option is by default turned on by some operating systems and off by some others.
Perl 5.16 or later or recent enough Socket.pm module is required for this parameter.
For more information about IPv6 support and address binding, see Section 3.4. IPv6 support and Section 3.5.9. BindAddress.