ReferenceSQL ReferenceFunctions

IP Address

IP Address functions reference.

IPv4CIDRToRange

Takes an IPv4 address with its Classless Inter-Domain Routing (CIDR) prefix length and returns the subnet's address range as a tuple of two IPv4 values: the first and last addresses in that subnet. For the IPv6 version see IPv6CIDRToRange.

Syntax

IPv4CIDRToRange(ipv4, cidr)

Arguments

Returned value

Returns a tuple with two IPv4 addresses representing the subnet range. Tuple(IPv4, IPv4)

Examples

Usage example

SELECT IPv4CIDRToRange(toIPv4('192.168.5.2'), 16);
┌─IPv4CIDRToRange(toIPv4('192.168.5.2'), 16)─┐
│ ('192.168.0.0','192.168.255.255')          │
└────────────────────────────────────────────┘

Introduced in version 20.1.

IPv4NumToString

Converts a 32-bit integer to its IPv4 address string representation in dotted decimal notation (A.B.C.D format). Interprets the input using big-endian byte ordering.

Syntax

IPv4NumToString(num)

Arguments

  • num — IPv4 address as UInt32 number. UInt32

Returned value

Returns a number representing the MAC address, or 0 if the format is invalid. String

Examples

Usage example

IPv4NumToString(3232235521)
192.168.0.1

Introduced in version 1.1.

IPv4NumToStringClassC

Converts a 32-bit integer to its IPv4 address string representation in dotted decimal notation (A.B.C.D format), similar to IPv4NumToString but using xxx instead of the last octet.

Syntax

IPv4NumToStringClassC(num)

Arguments

  • num — IPv4 address as UInt32 number. UInt32

Returned value

Returns the IPv4 address string with xxx replacing the last octet. String

Examples

Basic example with aggregation

SELECT
    IPv4NumToStringClassC(ClientIP) AS k,
    count() AS c
FROM test.hits
GROUP BY k
ORDER BY c DESC
LIMIT 10
┌─k──────────────┬─────c─┐
│ 83.149.9.xxx   │ 26238 │
│ 217.118.81.xxx │ 26074 │
│ 213.87.129.xxx │ 25481 │
│ 83.149.8.xxx   │ 24984 │
│ 217.118.83.xxx │ 22797 │
│ 78.25.120.xxx  │ 22354 │
│ 213.87.131.xxx │ 21285 │
│ 78.25.121.xxx  │ 20887 │
│ 188.162.65.xxx │ 19694 │
│ 83.149.48.xxx  │ 17406 │
└────────────────┴───────┘

Introduced in version 1.1.

IPv4StringToNum

Converts an IPv4 address string in dotted decimal notation (A.B.C.D format) to its corresponding 32-bit integer representation. (The reverse of IPv4NumToString). If the IPv4 address has an invalid format, an exception is thrown.

Syntax

IPv4StringToNum(string)

Arguments

  • string — IPv4 address string. String

Returned value

Returns theIPv4 address. UInt32

Examples

Usage example

IPv4StringToNum('192.168.0.1')
3232235521

Introduced in version 1.1.

IPv4StringToNumOrDefault

Converts an IPv4 address string in dotted decimal notation (A.B.C.D format) to its corresponding 32-bit integer representation but if the IPv4 address has an invalid format, it returns 0.

Syntax

IPv4StringToNumOrDefault(string)

Arguments

  • string — IPv4 address string. String

Returned value

Returns the IPv4 address, or 0 if invalid. UInt32

Examples

Example with an invalid address

SELECT
    IPv4StringToNumOrDefault('127.0.0.1') AS valid,
    IPv4StringToNumOrDefault('invalid') AS invalid;
┌──────valid─┬─invalid─┐
│ 2130706433 │       0 │
└────────────┴─────────┘

Introduced in version 22.3.

IPv4StringToNumOrNull

Converts a 32-bit integer to its IPv4 address string representation in dotted decimal notation (A.B.C.D format) but if the IPv4 address has an invalid format, it returns NULL.

Syntax

IPv4StringToNumOrNull(string)

Arguments

  • string — IPv4 address string. String

Returned value

Returns the IPv4 address, or NULL if invalid. Nullable(UInt32)

Examples

Example with an invalid address

SELECT
IPv4StringToNumOrNull('127.0.0.1') AS valid,
IPv4StringToNumOrNull('invalid') AS invalid;
┌──────valid─┬─invalid─┐
│ 2130706433 │    ᴺᵁᴸᴸ │
└────────────┴─────────┘

Introduced in version 22.3.

IPv4ToIPv6

Interprets a (big endian) 32-bit number as an IPv4 address, which is then interpreted as the corresponding IPv6 address in FixedString(16) format.

Syntax

IPv4ToIPv6(x)

Arguments

Returned value

Returns an IPv6 address in binary format. FixedString(16)

Examples

Usage example

SELECT IPv6NumToString(IPv4ToIPv6(IPv4StringToNum('192.168.0.1'))) AS addr;
┌─addr───────────────┐
│ ::ffff:192.168.0.1 │
└────────────────────┘

Introduced in version 1.1.

IPv6CIDRToRange

Takes an IPv6 address with its Classless Inter-Domain Routing (CIDR) prefix length and returns the subnet's address range as a tuple of two IPv6 values: the lowest and highest addresses in that subnet. For the IPv4 version see IPv4CIDRToRange.

Syntax

IPv6CIDRToRange(ipv6, cidr)

Arguments

Returned value

Returns a tuple with two IPv6 addresses representing the subnet range. Tuple(IPv6, IPv6)

Examples

Usage example

SELECT IPv6CIDRToRange(toIPv6('2001:0db8:0000:85a3:0000:0000:ac1f:8001'), 32);
┌─IPv6CIDRToRange(toIPv6('2001:0db8:0000:85a3:0000:0000:ac1f:8001'), 32)─┐
│ ('2001:db8::','2001:db8:ffff:ffff:ffff:ffff:ffff:ffff')                │
└────────────────────────────────────────────────────────────────────────┘

Introduced in version 20.1.

IPv6NumToString

Converts an IPv6 address from binary format (FixedString(16)) to its standard text representation. IPv4-mapped IPv6 addresses are displayed in the format ::ffff:111.222.33.44.

Syntax

IPv6NumToString(x)

Arguments

Returned value

Returns the IPv6 address string in text format. String

Examples

Usage example

SELECT IPv6NumToString(toFixedString(unhex('2A0206B8000000000000000000000011'), 16)) AS addr;
┌─addr─────────┐
│ 2a02:6b8::11 │
└──────────────┘

IPv6 with hits analysis

SELECT
    IPv6NumToString(ClientIP6 AS k),
    count() AS c
FROM hits_all
WHERE EventDate = today() AND substring(ClientIP6, 1, 12) != unhex('00000000000000000000FFFF')
GROUP BY k
ORDER BY c DESC
LIMIT 10
┌─IPv6NumToString(ClientIP6)──────────────┬─────c─┐
│ 2a02:2168:aaa:bbbb::2                   │ 24695 │
│ 2a02:2698:abcd:abcd:abcd:abcd:8888:5555 │ 22408 │
│ 2a02:6b8:0:fff::ff                      │ 16389 │
│ 2a01:4f8:111:6666::2                    │ 16016 │
│ 2a02:2168:888:222::1                    │ 15896 │
│ 2a01:7e00::ffff:ffff:ffff:222           │ 14774 │
│ 2a02:8109:eee:ee:eeee:eeee:eeee:eeee    │ 14443 │
│ 2a02:810b:8888:888:8888:8888:8888:8888  │ 14345 │
│ 2a02:6b8:0:444:4444:4444:4444:4444      │ 14279 │
│ 2a01:7e00::ffff:ffff:ffff:ffff          │ 13880 │
└─────────────────────────────────────────┴───────┘

IPv6 mapped IPv4 addresses

SELECT
    IPv6NumToString(ClientIP6 AS k),
    count() AS c
FROM hits_all
WHERE EventDate = today()
GROUP BY k
ORDER BY c DESC
LIMIT 10
┌─IPv6NumToString(ClientIP6)─┬──────c─┐
│ ::ffff:94.26.111.111       │ 747440 │
│ ::ffff:37.143.222.4        │ 529483 │
│ ::ffff:5.166.111.99        │ 317707 │
│ ::ffff:46.38.11.77         │ 263086 │
│ ::ffff:79.105.111.111      │ 186611 │
│ ::ffff:93.92.111.88        │ 176773 │
│ ::ffff:84.53.111.33        │ 158709 │
│ ::ffff:217.118.11.22       │ 154004 │
│ ::ffff:217.118.11.33       │ 148449 │
│ ::ffff:217.118.11.44       │ 148243 │
└────────────────────────────┴────────┘

Introduced in version 1.1.

IPv6StringToNum

Converts an IPv6 address from its standard text representation to binary format (FixedString(16)). Accepts IPv4-mapped IPv6 addresses in the format ::ffff:111.222.33.44.. If the IPv6 address has an invalid format, an exception is thrown.

If the input string contains a valid IPv4 address, returns its IPv6 equivalent. HEX can be uppercase or lowercase.

Syntax

IPv6StringToNum(string)

Arguments

  • string — IPv6 address string. String

Returned value

Returns theIPv6 address in binary format. FixedString(16)

Examples

Basic example

SELECT addr, cutIPv6(IPv6StringToNum(addr), 0, 0) FROM (SELECT ['notaddress', '127.0.0.1', '1111::ffff'] AS addr) ARRAY JOIN addr;
┌─addr───────┬─cutIPv6(IPv6StringToNum(addr), 0, 0)─┐
│ notaddress │ ::                                   │
│ 127.0.0.1  │ ::ffff:127.0.0.1                     │
│ 1111::ffff │ 1111::ffff                           │
└────────────┴──────────────────────────────────────┘

Introduced in version 1.1.

IPv6StringToNumOrDefault

Converts an IPv6 address from its standard text representation to binary format (FixedString(16)). Accepts IPv4-mapped IPv6 addresses in the format ::ffff:111.222.33.44.. If the IPv6 address has an invalid format, it returns the default value ::.

Syntax

IPv6StringToNumOrDefault(string)

Arguments

  • string — IPv6 address string. String

Returned value

IPv6 address in binary format, or zero-filled FixedString(16) if invalid. FixedString(16)

Examples

Basic example with invalid address

SELECT
    IPv6NumToString(IPv6StringToNumOrDefault('2001:db8::1')) AS valid,
    IPv6NumToString(IPv6StringToNumOrDefault('invalid')) AS invalid;
┌─valid───────┬─invalid─┐
│ 2001:db8::1 │ ::      │
└─────────────┴─────────┘

Introduced in version 22.3.

IPv6StringToNumOrNull

Converts an IPv6 address from its standard text representation to binary format (FixedString(16)). Accepts IPv4-mapped IPv6 addresses in the format ::ffff:111.222.33.44.. If the IPv6 address has an invalid format, it returns NULL.

Syntax

IPv6StringToNumOrNull(string)

Arguments

  • string — IPv6 address string. String

Returned value

Returns IPv6 address in binary format, or NULL if invalid. Nullable(FixedString(16))

Examples

Basic example with invalid address

SELECT
    IPv6NumToString(IPv6StringToNumOrNull('2001:db8::1')) AS valid,
    IPv6StringToNumOrNull('invalid') AS invalid;
┌─valid───────┬─invalid─┐
│ 2001:db8::1 │    ᴺᵁᴸᴸ │
└─────────────┴─────────┘

Introduced in version 22.3.

cutIPv6

Accepts a FixedString(16) value containing the IPv6 address in binary format. Returns a string containing the address of the specified number of bytes removed in text format.

Syntax

cutIPv6(x, bytesToCutForIPv6, bytesToCutForIPv4)

Arguments

  • x — IPv6 address in binary format. FixedString(16) or IPv6
  • bytesToCutForIPv6 — Number of bytes to cut for IPv6. UInt8
  • bytesToCutForIPv4 — Number of bytes to cut for IPv4. UInt8

Returned value

Returns a string containing the IPv6 address in text format with specified bytes removed. String

Examples

Usage example

WITH
    IPv6StringToNum('2001:0DB8:AC10:FE01:FEED:BABE:CAFE:F00D') AS ipv6,
    IPv4ToIPv6(IPv4StringToNum('192.168.0.1')) AS ipv4
SELECT
    cutIPv6(ipv6, 2, 0),
    cutIPv6(ipv4, 0, 2)
┌─cutIPv6(ipv6, 2, 0)─────────────────┬─cutIPv6(ipv4, 0, 2)─┐
│ 2001:db8:ac10:fe01:feed:babe:cafe:0 │ ::ffff:192.168.0.0  │
└─────────────────────────────────────┴─────────────────────┘

Introduced in version 1.1.

isIPAddressInRange

Determines if an IP address is contained in a network represented in the Classless Inter-Domain Routing (CIDR) notation.

This function accepts both IPv4 and IPv6 addresses (and networks) represented as strings. It returns 0 if the IP version of the address and the CIDR don't match.

Syntax

isIPAddressInRange(address, prefix)

Arguments

  • address — An IPv4 or IPv6 address. String
  • prefix — An IPv4 or IPv6 network prefix in CIDR. String

Returned value

Returns 1 if the IP version of the address and the CIDR match, otherwise 0. UInt8

Examples

IPv4 address in range

SELECT isIPAddressInRange('127.0.0.1', '127.0.0.0/8')
1

IPv4 address not in range

SELECT isIPAddressInRange('127.0.0.1', 'ffff::/16')
0

IPv6 address not in range

SELECT isIPAddressInRange('::ffff:192.168.0.1', '::ffff:192.168.0.4/128')
0

Introduced in version 21.4.

isIPv4String

Determines whether the input string is an IPv4 address or not. For the IPv6 version see isIPv6String.

Syntax

isIPv4String(string)

Arguments

  • string — IP address string to check. String

Returned value

Returns 1 if string is IPv4 address, otherwise 0. UInt8

Examples

Usage example

SELECT addr, isIPv4String(addr)
FROM(
SELECT ['0.0.0.0', '127.0.0.1', '::ffff:127.0.0.1'] AS addr
)
ARRAY JOIN addr;
┌─addr─────────────┬─isIPv4String(addr)─┐
│ 0.0.0.0          │                  1 │
│ 127.0.0.1        │                  1 │
│ ::ffff:127.0.0.1 │                  0 │
└──────────────────┴────────────────────┘

Introduced in version 21.1.

isIPv6String

Determines whether the input string is an IPv6 address or not. For the IPv4 version see isIPv4String.

Syntax

isIPv6String(string)

Arguments

  • string — IP address string to check. String

Returned value

Returns 1 if string is IPv6 address, otherwise 0. UInt8

Examples

Usage example

SELECT addr, isIPv6String(addr)
FROM(SELECT ['::', '1111::ffff', '::ffff:127.0.0.1', '127.0.0.1'] AS addr)
ARRAY JOIN addr;
┌─addr─────────────┬─isIPv6String(addr)─┐
│ ::               │                  1 │
│ 1111::ffff       │                  1 │
│ ::ffff:127.0.0.1 │                  1 │
│ 127.0.0.1        │                  0 │
└──────────────────┴────────────────────┘

Introduced in version 21.1.

toIPv4

Converts a string or a UInt32 form of IPv4 address to type IPv4. It is similar to IPv4StringToNum and IPv4NumToString functions but it supports both string and unsigned integer data types as input arguments.

Syntax

toIPv4(x)

Arguments

Returned value

Returns an IPv4 address. IPv4

Examples

Usage example

SELECT toIPv4('171.225.130.45');
┌─toIPv4('171.225.130.45')─┐
│ 171.225.130.45           │
└──────────────────────────┘

Comparison with IPv4StringToNum and IPv4NumToString functions.

WITH
    '171.225.130.45' AS IPv4_string
SELECT
    hex(IPv4StringToNum(IPv4_string)),
    hex(toIPv4(IPv4_string))
┌─hex(IPv4StringToNum(IPv4_string))─┬─hex(toIPv4(IPv4_string))─┐
│ ABE1822D                          │ ABE1822D                 │
└───────────────────────────────────┴──────────────────────────┘

Conversion from an integer

SELECT toIPv4(2130706433);
┌─toIPv4(2130706433)─┐
│ 127.0.0.1          │
└────────────────────┘

Introduced in version 20.1.

toIPv4OrDefault

Converts a string or a UInt32 form of an IPv4 address to IPv4 type. If the IPv4 address has an invalid format, it returns 0.0.0.0 (0 IPv4), or the provided IPv4 default.

Syntax

toIPv4OrDefault(string[, default])

Arguments

  • string — IP address string to convert. String
  • default — Optional. The value to return if string is an invalid IPv4 address. IPv4

Returned value

Returns a string converted to the current IPv4 address, or the default value if conversion fails. IPv4

Examples

Valid and invalid IPv4 strings

WITH
    '192.168.1.1' AS valid_IPv4_string,
    '999.999.999.999' AS invalid_IPv4_string,
    'not_an_ip' AS malformed_string
SELECT
    toIPv4OrDefault(valid_IPv4_string) AS valid,
    toIPv4OrDefault(invalid_IPv4_string) AS default_value,
    toIPv4OrDefault(malformed_string, toIPv4('8.8.8.8')) AS provided_default;
┌─valid─────────┬─default_value─┬─provided_default─┐
│ 192.168.1.1   │ 0.0.0.0       │ 8.8.8.8          │
└───────────────┴───────────────┴──────────────────┘

Introduced in version 22.3.

toIPv4OrNull

Converts an input value to a value of type IPv4 but returns NULL in case of an error. Like toIPv4 but returns NULL instead of throwing an exception on conversion errors.

Supported arguments:

  • String representations of IPv4 addresses in dotted decimal notation.
  • Integer representations of IPv4 addresses.

Unsupported arguments (return NULL):

  • Invalid IP address formats.
  • IPv6 addresses.
  • Out-of-range values.
  • Malformed addresses.

Syntax

toIPv4OrNull(x)

Arguments

  • x — A string or integer representation of an IPv4 address. String or Integer

Returned value

Returns an IPv4 address if successful, otherwise NULL. IPv4 or NULL

Examples

Usage example

SELECT
    toIPv4OrNull('192.168.1.1') AS valid_ip,
    toIPv4OrNull('invalid.ip') AS invalid_ip
┌─valid_ip────┬─invalid_ip─┐
│ 192.168.1.1 │       ᴺᵁᴸᴸ │
└─────────────┴────────────┘

Introduced in version 22.3.

toIPv4OrZero

Converts an input value to a value of type IPv4 but returns zero IPv4 address in case of an error. Like toIPv4 but returns zero IPv4 address (0.0.0.0) instead of throwing an exception on conversion errors.

Supported arguments:

  • String representations of IPv4 addresses in dotted decimal notation.
  • Integer representations of IPv4 addresses.

Unsupported arguments (return zero IPv4):

  • Invalid IP address formats.
  • IPv6 addresses.
  • Out-of-range values.

Syntax

toIPv4OrZero(x)

Arguments

  • x — A string or integer representation of an IPv4 address. String or Integer

Returned value

Returns an IPv4 address if successful, otherwise zero IPv4 address (0.0.0.0). IPv4

Examples

Usage example

SELECT
    toIPv4OrZero('192.168.1.1') AS valid_ip,
    toIPv4OrZero('invalid.ip') AS invalid_ip
┌─valid_ip────┬─invalid_ip─┐
│ 192.168.1.1 │ 0.0.0.0    │
└─────────────┴────────────┘

Introduced in version 23.1.

toIPv6

onverts a string or a UInt128 form of IPv6 address to IPv6 type. For strings, if the IPv6 address has an invalid format, returns an empty value. Similar to IPv6StringToNum and IPv6NumToString functions, which convert IPv6 address to and from binary format (i.e. FixedString(16)).

If the input string contains a valid IPv4 address, then the IPv6 equivalent of the IPv4 address is returned.

Syntax

toIPv6(x)

Arguments

Returned value

Returns an IPv6 address. IPv6

Examples

Usage example

WITH '2001:438:ffff::407d:1bc1' AS IPv6_string
SELECT
    hex(IPv6StringToNum(IPv6_string)),
    hex(toIPv6(IPv6_string));
┌─hex(IPv6StringToNum(IPv6_string))─┬─hex(toIPv6(IPv6_string))─────────┐
│ 20010438FFFF000000000000407D1BC1  │ 20010438FFFF000000000000407D1BC1 │
└───────────────────────────────────┴──────────────────────────────────┘

IPv4-to-IPv6 mapping

SELECT toIPv6('127.0.0.1');
┌─toIPv6('127.0.0.1')─┐
│ ::ffff:127.0.0.1    │
└─────────────────────┘

Introduced in version 20.1.

toIPv6OrDefault

Converts a string or a UInt128 form of IPv6 address to IPv6 type. If the IPv6 address has an invalid format, it returns :: (0 IPv6) or the provided IPv6 default.

Syntax

toIPv6OrDefault(string[, default])

Arguments

  • string — IP address string to convert. - default — Optional. The value to return if string has an invalid format.

Returned value

Returns the IPv6 address, otherwise :: or the provided optional default if argument string has an invalid format. IPv6

Examples

Valid and invalid IPv6 strings

WITH
    '2001:0db8:85a3:0000:0000:8a2e:0370:7334' AS valid_IPv6_string,
    '2001:0db8:85a3::8a2e:370g:7334' AS invalid_IPv6_string,
    'not_an_ipv6' AS malformed_string
SELECT
    toIPv6OrDefault(valid_IPv6_string) AS valid,
    toIPv6OrDefault(invalid_IPv6_string) AS default_value,
    toIPv6OrDefault(malformed_string, toIPv6('::1')) AS provided_default;
┌─valid──────────────────────────────────┬─default_value─┬─provided_default─┐
│ 2001:db8:85a3::8a2e:370:7334           │ ::            │ ::1              │
└────────────────────────────────────────┴───────────────┴──────────────────┘

Introduced in version 22.3.

toIPv6OrNull

Converts an input value to a value of type IPv6 but returns NULL in case of an error. Like toIPv6 but returns NULL instead of throwing an exception on conversion errors.

Supported arguments:

  • String representations of IPv6 addresses in standard notation.
  • String representations of IPv4 addresses (converted to IPv4-mapped IPv6).
  • Binary representations of IPv6 addresses.

Unsupported arguments (return NULL):

  • Invalid IP address formats.
  • Malformed IPv6 addresses.
  • Out-of-range values.
  • Invalid notation.

Syntax

toIPv6OrNull(x)

Arguments

  • x — A string representation of an IPv6 or IPv4 address. String

Returned value

Returns an IPv6 address if successful, otherwise NULL. IPv6 or NULL

Examples

Usage example

SELECT
    toIPv6OrNull('2001:0db8:85a3:0000:0000:8a2e:0370:7334') AS valid_ipv6,
    toIPv6OrNull('invalid::ip') AS invalid_ipv6
┌─valid_ipv6──────────────────────────┬─invalid_ipv6─┐
│ 2001:db8:85a3::8a2e:370:7334        │         ᴺᵁᴸᴸ │
└─────────────────────────────────────┴──────────────┘

Introduced in version 22.3.

toIPv6OrZero

Converts an input value to a value of type IPv6 but returns zero IPv6 address in case of an error. Like toIPv6 but returns zero IPv6 address (::) instead of throwing an exception on conversion errors.

Supported arguments:

  • String representations of IPv6 addresses in standard notation.
  • String representations of IPv4 addresses (converted to IPv4-mapped IPv6).
  • Binary representations of IPv6 addresses.

Unsupported arguments (return zero IPv6):

  • Invalid IP address formats.
  • Malformed IPv6 addresses.
  • Out-of-range values.

Syntax

toIPv6OrZero(x)

Arguments

  • x — A string representation of an IPv6 or IPv4 address. String

Returned value

Returns an IPv6 address if successful, otherwise zero IPv6 address (::). IPv6

Examples

Usage example

SELECT
    toIPv6OrZero('2001:0db8:85a3:0000:0000:8a2e:0370:7334') AS valid_ipv6,
    toIPv6OrZero('invalid::ip') AS invalid_ipv6
┌─valid_ipv6──────────────────────────┬─invalid_ipv6─┐
│ 2001:db8:85a3::8a2e:370:7334        │ ::           │
└─────────────────────────────────────┴──────────────┘

Introduced in version 23.1.

Introspection

Introspection functions reference.

JSON

JSON functions reference.

On this page

IPv4CIDRToRangeIPv4NumToStringIPv4NumToStringClassCIPv4StringToNumIPv4StringToNumOrDefaultIPv4StringToNumOrNullIPv4ToIPv6IPv6CIDRToRangeIPv6NumToStringIPv6StringToNumIPv6StringToNumOrDefaultIPv6StringToNumOrNullcutIPv6isIPAddressInRangeisIPv4StringisIPv6StringtoIPv4toIPv4OrDefaulttoIPv4OrNulltoIPv4OrZerotoIPv6toIPv6OrDefaulttoIPv6OrNulltoIPv6OrZero