Miscellaneous Functions Given an IPv6 or IPv4 network address as a string, returns a binary string that represents the numeric value of the address in network byte order (big endian). Because numeric-format IPv6 addresses require more bytes than the largest integer type, the representation returned by this function has the VARBINARY  data type:  VARBINARY(16)  for IPv6 addresses and  VARBINARY(4)  for IPv4 addresses. If the argument is not a valid address,  INET6_ATON()  returns  NULL . The following examples use  HEX()  to display the  INET6_ATON()  result in printable form: INET6_ATON()  observes several constraints on valid arguments. These are given in the following list along with examples. To convert an IPv4 address  expr  represented in numeric form as an  INT  value to an IPv6 address represented in numeric form as a  VARBINARY  value, use this expression: INET6_ATON(INET_NTOA( expr )) For example: mysql>  SELECT HEX(INET6_ATON(INET_NTOA(167773449))); -> ’0A000509’ If  INET6_ATON()  is invoked from within the  mysql  client, binary strings display using hexadecimal notation, depending on the value of the  --binary-as-hex . For more information about that option, see Section 4.5.1, “mysql — The MySQL Command-Line Client” . 2445 •For values representing IPv4 addresses, only classless addresses are supported. Classful addresses such as  198.51.1  are rejected. A trailing port number is not permitted, as in  198.51.100.2:8080 . Hexadecimal numbers in address components are not permitted, as in  198.0xa0.1.2 . Octal numbers are not supported:  198.51.010.1  is treated as  198.51.10.1 , not  198.51.8.1 . These IPv4 constraints also apply to IPv6 addresses that have IPv4 address parts, such as IPv4-compatible or IPv4-mapped addresses. •A trailing network mask is not permitted, as in  2001:45f:3:ba::/64  or  198.51.100.0/24 . •A trailing zone ID is not permitted, as in  fe80::3%1  or  fe80::3%eth0 . • INET6_ATON( expr ) mysql>  SELECT HEX(INET6_ATON(’fdfe::5a55:caff:fefa:9089’)); -> ’FDFE0000000000005A55CAFFFEFA9089’ mysql>  SELECT HEX(INET6_ATON(’10.0.5.9’)); -> ’0A000509’