# IP address and network functions

Network functions inspect addresses and subnet prefixes. `inet` can retain host bits with a prefix; `cidr` represents a network and validates its host bits. IPv4 and IPv6 native values can be used where the function admits an address.

Functions parse numeric addresses, not hostnames, and do not perform DNS lookups. Prefix lengths range from 0 through 32 for IPv4 and 0 through 128 for IPv6.

## Example: Separating a host from its network

```sql
SELECT CAST(network('192.0.2.17/24') AS TEXT),
       host('192.0.2.17/24'), masklen('192.0.2.17/24')
FORMAT csv;
```

```text
"192.0.2.0/24","192.0.2.17",24
```

## broadcast

Set every host bit in an address.

### Syntax

```text
broadcast(address)
```

### Arguments

Native IPv4/IPv6/inet/cidr or bounded full IPv4/IPv6 text with optional /prefix. Preserve inet host bits, validate cidr host bits. Prefixes 0..32 or 0..128. No DNS. NULL propagates.

### Returned value

inet

### Example

```sql
SELECT CAST(broadcast('192.168.1.5/24') AS TEXT) FORMAT csv;
```

```text
"192.168.1.255/24"
```

## family

Return 4 for IPv4 or 6 for IPv6.

### Syntax

```text
family(address)
```

### Arguments

Native IPv4/IPv6/inet/cidr or bounded full IPv4/IPv6 text with optional /prefix. Preserve inet host bits, validate cidr host bits. Prefixes 0..32 or 0..128. No DNS. NULL propagates.

### Returned value

INTEGER

### Example

```sql
SELECT family('::1') FORMAT csv;
```

```text
6
```

## host

Return address text without its prefix.

### Syntax

```text
host(address)
```

### Arguments

Native IPv4/IPv6/inet/cidr or bounded full IPv4/IPv6 text with optional /prefix. Preserve inet host bits, validate cidr host bits. Prefixes 0..32 or 0..128. No DNS. NULL propagates.

### Returned value

String

### Example

```sql
SELECT host('192.168.1.5/24') FORMAT csv;
```

```text
"192.168.1.5"
```

## hostmask

Return the inverse network mask as an address.

### Syntax

```text
hostmask(address)
```

### Arguments

Native IPv4/IPv6/inet/cidr or bounded full IPv4/IPv6 text with optional /prefix. Preserve inet host bits, validate cidr host bits. Prefixes 0..32 or 0..128. No DNS. NULL propagates.

### Returned value

inet

### Example

```sql
SELECT CAST(hostmask('192.168.1.5/24') AS TEXT) FORMAT csv;
```

```text
"0.0.0.255"
```

## inet_merge

Find the smallest subnet covering both inputs.

### Syntax

```text
inet_merge(address,other)
```

### Arguments

Native IPv4/IPv6/inet/cidr or bounded full IPv4/IPv6 text with optional /prefix. Preserve inet host bits, validate cidr host bits. Prefixes 0..32 or 0..128. No DNS. NULL propagates.

### Returned value

cidr

### Example

```sql
SELECT CAST(inet_merge('192.168.1.5/24','192.168.2.5/24') AS TEXT) FORMAT csv;
```

```text
"192.168.0.0/22"
```

## inet_same_family

Test whether both addresses have the same family.

### Syntax

```text
inet_same_family(address,other)
```

### Arguments

Native IPv4/IPv6/inet/cidr or bounded full IPv4/IPv6 text with optional /prefix. Preserve inet host bits, validate cidr host bits. Prefixes 0..32 or 0..128. No DNS. NULL propagates.

### Returned value

Bool

### Example

```sql
SELECT inet_same_family('192.168.1.5','::1') FORMAT csv;
```

```text
false
```

## masklen

Return the prefix length in bits.

### Syntax

```text
masklen(address)
```

### Arguments

Native IPv4/IPv6/inet/cidr or bounded full IPv4/IPv6 text with optional /prefix. Preserve inet host bits, validate cidr host bits. Prefixes 0..32 or 0..128. No DNS. NULL propagates.

### Returned value

INTEGER

### Example

```sql
SELECT masklen('192.168.1.5/24') FORMAT csv;
```

```text
24
```

## netmask

Return the network mask as an address.

### Syntax

```text
netmask(address)
```

### Arguments

Native IPv4/IPv6/inet/cidr or bounded full IPv4/IPv6 text with optional /prefix. Preserve inet host bits, validate cidr host bits. Prefixes 0..32 or 0..128. No DNS. NULL propagates.

### Returned value

inet

### Example

```sql
SELECT CAST(netmask('192.168.1.5/24') AS TEXT) FORMAT csv;
```

```text
"255.255.255.0"
```

## network

Return the subnet with cleared host bits.

### Syntax

```text
network(address)
```

### Arguments

Native IPv4/IPv6/inet/cidr or bounded full IPv4/IPv6 text with optional /prefix. Preserve inet host bits, validate cidr host bits. Prefixes 0..32 or 0..128. No DNS. NULL propagates.

### Returned value

cidr

### Example

```sql
SELECT CAST(network('192.168.1.5/24') AS TEXT) FORMAT csv;
```

```text
"192.168.1.0/24"
```

## set_masklen

Change a prefix, clearing host bits for cidr.

### Syntax

```text
set_masklen(address,prefix)
```

### Arguments

Native IPv4/IPv6/inet/cidr or bounded full IPv4/IPv6 text with optional /prefix. Preserve inet host bits, validate cidr host bits. Prefixes 0..32 or 0..128. No DNS. NULL propagates.

### Returned value

inet or cidr

### Example

```sql
SELECT CAST(set_masklen('192.168.1.5/24',16) AS TEXT) FORMAT csv;
```

```text
"192.168.1.5/16"
```