# DHCP Snooping

The `nv unset` commands remove the configuration you set with the equivalent `nv set` commands. This guide only describes an `nv unset` command if it differs from the `nv set` command.

## nv set bridge domain <domain-id> dhcp-snoop vlan <vid>

Enables DHCP snooping for IPv4 on a VLAN under a bridge.

### Command Syntax

Syntax | Description
--- | ---
`<domain-id>` | The bridge name.
`<vlan-id>` | The VLAN name.

### Version History

Introduced in Cumulus Linux 5.11.0

### Example

    cumulus@switch:~$ nv set bridge domain br_default dhcp-snoop vlan 10

## nv set bridge domain <domain-id> dhcp-snoop vlan <vid> trust <interface-id>

Configures a trusted interface for IPv4. Cumulus Linux allows DHCP offers from only trusted interfaces to prevent malicious DHCP servers from assigning IPv4 addresses inside the network. The interface must be a member of the bridge you specify.

### Command Syntax

Syntax | Description
--- | ---
`<domain-id>` | The bridge name.
`<vlan-id>` | The VLAN name.
`<interface-id>` | The trusted interface ID.

### Version History

Introduced in Cumulus Linux 5.11.0

### Example

    cumulus@switch:~$ nv set bridge domain br_default dhcp-snoop vlan 10 trust swp3

## nv set bridge domain <domain-id> dhcp-snoop6 vlan <vid>

Enables DHCP snooping for IPv6 on a VLAN under a bridge.

### Command Syntax

Syntax | Description
--- | ---
`<domain-id>` | The bridge name.
`<vlan-id>` | The VLAN name.

### Version History

Introduced in Cumulus Linux 5.11.0

### Example

    cumulus@switch:~$ nv set bridge domain br_default dhcp-snoop6 vlan 10

## nv set bridge domain <domain-id> dhcp-snoop6 vlan <vid> trust <interface-id>

Configures a trusted interface for IPv6. Cumulus Linux allows DHCP offers from only trusted interfaces to prevent malicious DHCP servers from assigning IPv6 addresses inside the network. The interface must be a member of the bridge you specify.

### Command Syntax

Syntax | Description
--- | ---
`<domain-id>` | The bridge name.
`<vlan-id>` | The VLAN name.
`<interface-id>` | The trusted interface ID.

### Version History

Introduced in Cumulus Linux 5.11.0

### Example

    cumulus@switch:~$ nv set bridge domain br_default dhcp-snoop6 vlan 10 trust swp3