# Functions for working with IP addresses

## IPv4NumToString(num)

Takes a UInt32 number. Interprets it as an IPv4 address in big endian. Returns a string containing the corresponding IPv4 address in the format A.B.C.d (dot-separated numbers in decimal form).

## IPv4StringToNum(s)

The reverse function of IPv4NumToString. If the IPv4 address has an invalid format, it returns 0.

## IPv4NumToStringClassC(num)

Similar to IPv4NumToString, but using xxx instead of the last octet.

Example:

```sql
SELECT
    IPv4NumToStringClassC(ClientIP) AS k,
    count() AS c
FROM test.hits
GROUP BY k
ORDER BY c DESC
LIMIT 10
```

```text
┌─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 │
└────────────────┴───────┘
```

Since using 'xxx' is highly unusual, this may be changed in the future. We recommend that you don't rely on the exact format of this fragment.

### IPv6NumToString(x)

Accepts a FixedString(16) value containing the IPv6 address in binary format. Returns a string containing this address in text format.
IPv6-mapped IPv4 addresses are output in the format ::ffff:111.222.33.44. Examples:

```sql
SELECT IPv6NumToString(toFixedString(unhex('2A0206B8000000000000000000000011'), 16)) AS addr
```

```text
┌─addr─────────┐
│ 2a02:6b8::11 │
└──────────────┘
```

```sql
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
```

```text
┌─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 │
└─────────────────────────────────────────┴───────┘
```

```sql
SELECT
    IPv6NumToString(ClientIP6 AS k),
    count() AS c
FROM hits_all
WHERE EventDate = today()
GROUP BY k
ORDER BY c DESC
LIMIT 10
```

```text
┌─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 │
└────────────────────────────┴────────┘
```

## IPv6StringToNum(s)

The reverse function of IPv6NumToString. If the IPv6 address has an invalid format, it returns a string of null bytes.
HEX can be uppercase or lowercase.

## IPv4ToIPv6(x)

Takes a `UInt32` number. Interprets it as an IPv4 address in [big endian](https://en.wikipedia.org/wiki/Endianness). Returns a `FixedString(16)` value containing the IPv6 address in binary format. Examples:

```sql
SELECT IPv6NumToString(IPv4ToIPv6(IPv4StringToNum('192.168.0.1'))) AS addr
```

```text
┌─addr───────────────┐
│ ::ffff:192.168.0.1 │
└────────────────────┘
```

## cutIPv6(x, bitsToCutForIPv6, bitsToCutForIPv4)

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

```sql
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)

```

```text
┌─cutIPv6(ipv6, 2, 0)─────────────────┬─cutIPv6(ipv4, 0, 2)─┐
│ 2001:db8:ac10:fe01:feed:babe:cafe:0 │ ::ffff:192.168.0.0  │
└─────────────────────────────────────┴─────────────────────┘
```

## IPv4CIDRToRange(ipv4, cidr),

Accepts an IPv4 and an UInt8 value containing the [CIDR](https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing). Return a tuple with two IPv4 containing the lower range and the higher range of the subnet.


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


## IPv6CIDRToRange(ipv6, cidr),

Accepts an IPv6 and an UInt8 value containing the CIDR. Return a tuple with two IPv6 containing the lower range and the higher range of the subnet.


```sql
SELECT IPv6CIDRToRange(toIPv6('2001:0db8:0000:85a3:0000:0000:ac1f:8001'), 32);
```

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

## toIPv4(string)

An alias to `IPv4StringToNum()` that takes a string form of IPv4 address and returns value of [IPv4](../../data_types/domains/ipv4.md) type, which is binary equal to value returned by `IPv4StringToNum()`.

```sql
WITH
    '171.225.130.45' as IPv4_string
SELECT
    toTypeName(IPv4StringToNum(IPv4_string)),
    toTypeName(toIPv4(IPv4_string))
```

```text
┌─toTypeName(IPv4StringToNum(IPv4_string))─┬─toTypeName(toIPv4(IPv4_string))─┐
│ UInt32                                   │ IPv4                            │
└──────────────────────────────────────────┴─────────────────────────────────┘
```

```sql
WITH
    '171.225.130.45' as IPv4_string
SELECT
    hex(IPv4StringToNum(IPv4_string)),
    hex(toIPv4(IPv4_string))
```

```text
┌─hex(IPv4StringToNum(IPv4_string))─┬─hex(toIPv4(IPv4_string))─┐
│ ABE1822D                          │ ABE1822D                 │
└───────────────────────────────────┴──────────────────────────┘
```

## toIPv6(string)

An alias to `IPv6StringToNum()` that takes a string form of IPv6 address and returns value of [IPv6](../../data_types/domains/ipv6.md) type, which is binary equal to value returned by `IPv6StringToNum()`.

```sql
WITH
    '2001:438:ffff::407d:1bc1' as IPv6_string
SELECT
    toTypeName(IPv6StringToNum(IPv6_string)),
    toTypeName(toIPv6(IPv6_string))
```

```text
┌─toTypeName(IPv6StringToNum(IPv6_string))─┬─toTypeName(toIPv6(IPv6_string))─┐
│ FixedString(16)                          │ IPv6                            │
└──────────────────────────────────────────┴─────────────────────────────────┘
```

```sql
WITH
    '2001:438:ffff::407d:1bc1' as IPv6_string
SELECT
    hex(IPv6StringToNum(IPv6_string)),
    hex(toIPv6(IPv6_string))
```

```text
┌─hex(IPv6StringToNum(IPv6_string))─┬─hex(toIPv6(IPv6_string))─────────┐
│ 20010438FFFF000000000000407D1BC1  │ 20010438FFFF000000000000407D1BC1 │
└───────────────────────────────────┴──────────────────────────────────┘
```

[Original article](https://clickhouse.tech/docs/en/query_language/functions/ip_address_functions/) <!--hide-->