---
name: "dhcp6ctl"
section: "8"
platform: "linux"
package: "wide-dhcpv6-client"
version: "20080615-24"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/dhcp6ctl"
---

# dhcp6ctl(8)

DHCPv6 client and server control utility

## NAME

**dhcp6ctl** – DHCPv6 client and server control utility

## SYNOPSIS

**dhcp6ctl** \[**-C** **-\|** **-S**\] \[**-k** *keyfile*\] \[**-p** *port*\] \[**-s** *address*\] **command**

## DESCRIPTION

**dhcp6ctl** controls the operation of a DHCPv6 process, which is either **dhcp6c** or **dhcp6s**, a DHCPv6 client or a server. By default, **dhcp6ctl** controls a client. The type of the process can also be specified explicitly by the **-C** or **-S** options.

**dhcp6ctl** communicates with the DHCPv6 process over a TCP connection, sending commands authenticated with digital signatures. Currently, the only supported authentication algorithm is HMAC-MD5, which uses a shared secret on each end of the connection.

Command line options are as below:

- **-C**

  Control a DHCPv6 client. This option is exclusive with the **-S** option.

- **-S**

  Control a DHCPv6 server. This option is exclusive with the **-C** option.

- **-k** *keyfile*

  Use *keyfile* to provide the shared secret to communicate with the process. The default file name used when unspecified is */etc/wide-dhcpv6/dhcp6cctlkey* with a client, and */etc/wide-dhcpv6/dhcp6sctlkey* with a server.

- **-p** *port*

  Specify *port* as the listening port of the process. The default port number used when unspecified is 5546 for a client, and 5547 for a server.

- **-s** *address*

  Specify *address* as the listening address of the process. The default address used when unspecified is ::1.

## KEY FILE

Since the operation available with the **dhcp6ctl** command is powerful, the communication between the command and **dhcp6c** or **dhcp6s** must be authenticated. The supported algorithm for authentication is HMAC-MD5, which requires a shared secret, and the secret is stored in the key file. The key file must consist of a single line, in which the secret value is written in the form of BASE-64 encoding.

## COMMANDS

Each **command** specifies a single control operation. Supported commands are as follows:

-

  **reload** This command specifies the process to reload the configuration file. Existing bindings, if any, are intact.

-

  **remove** *arguments* This command is only applicable to a server. This specifies the server to remove a run-time object specified by *arguments* from the server. Currently, the only possible object is one particular IA\_NA or IA\_PD binding, which is specified as ‘**binding** **IA** **IA\_NA** *IAID* *DUID*’ or ‘**binding** **IA** **IA\_PD** *IAID* *DUID*’ where *IAID* is a decimal number specifying the IAID of the IA, and *DUID* is a DHCP Unique Identifier of the binding. The format of *DUID* is the same as that specified in [dhcp6s.conf(5)](/dhcp6s.conf/5.md).

-

  **start** **interface** *ifname* This command is only applicable to a client. It tells the client to release the current configuration information (if any) on the interface *ifname* and restart the DHCPv6 configuration process on the interface.

-

  **stop** **interface** *ifname* This command is only applicable to a client. It tells the client to release the current configuration information (if any) on the interface *ifname*. Any timer running for the interface will be stopped, and no more DHCPv6 messages will be sent on the interface. The configuration process can later be restarted by the **start** command.

-

  **stop** This command stops the specified process. If the process is a client, it will release all configuration information (if any) and exits.

## FILES

- */etc/wide-dhcpv6/dhcp6cctlkey*

  is the default key file to communicate with a client.

- */etc/wide-dhcpv6/dhcp6sctlkey*

  is the default key file to communicate with a server.

## SEE ALSO

[dhcp6s.conf(5)](/dhcp6s.conf/5.md) [dhcp6s(8)](/dhcp6s/8.md)

## HISTORY

The **dhcp6ctl** command first appeared in WIDE/KAME IPv6 protocol stack kit.