WIDE-DHCPv6 client configuration and dhcp6c manual

WIDE-DHCPv6 client configuration

The /etc/config/dhcp6c file controls the WIDE-DHCPv6 client package wide-dhcpv6-client configuration. It defines basic properties and interface settings.

Sections

A typical default configuration consists of one dhcp6c section with common settings and one or more interface sections, usually covering the lan and loopback networks.

Basic Properties

The section of type dhcp6c named basic defines common client settings.

Example:

config 'dhcp6c' 'basic' option 'enabled' '1' option 'interface' 'wan' option 'pd' '1' option 'domain_name_servers' '1' option 'script' '/usr/bin/dhcp6c-state'

All defined options of this section are listed below.

Name	Type	Required	Default	Description
enabled	boolean	no	0	Specifies whether the DHCPv6 client should be started on boot
interface	string	yes	wan	Specifies the logical interface name the client is running on
dns	string	no	dnsmasq	Specifies the type of DNS server in use to propagate received DNS information. At the time of writing, only dnsmasq is supported
debug	boolean	no	0	Enables additional debug information in the system log
pd	boolean	no	1	Requests prefix delegation at the DHCPv6 server
na	boolean	no	0	Requests a permanent, non temporary address at the DHCPv6 server
rapid_commit	boolean	no	1	Signalize a rapid commit two message exchange (RFC3315)
domain_name_servers	boolean	no	1	Request a DNS server addresses
domain_name	boolean	no	0	Request the domain name
ntp_servers	boolean	no	0	Request NTP server addresses (RFC5908)
sip_server_address	boolean	no	0	Request SIP server address (RFC3319)
sip_server_domain_name	boolean	no	0	Request SIP domain names (RFC3319)
nis_server_address	boolean	no	0	Request Network Information Service (NIS) server address (RFC3898)
nis_domain_name	boolean	no	0	Request Network Information Service (NIS) domain name (RFC3898)
nisp_server_address	boolean	no	0	Request Network Information Service V2 (NIS+) server address (RFC3898)
nisp_domain_name	boolean	no	0	Request Network Information Service V2 (NIS+) domain name (RFC3898)
bcmcs_server_address	boolean	no	0	Request Broadcast and Multicast Control Service (BCMCS) address (RFC4280)
bcmcs_server_domain_name	boolean	no	0	Request Broadcast and Multicast Control Service (BCMCS) domain name (RFC4280)
duid	string	no	(derived from MAC address)	Override the DUID used for DHCPv6 requests. The DUID must be specified as a set of at least 7 colon separated heximal digits, e.g. 00:03:00:06:D8:5D:4C:A5:03:F2
script	file path	no	/usr/bin/dhcp6c-state	Path of script which is executed when a reply is received

Interface Settings

Sections of type interface define on which interfaces delegated prefixes are added and how they're aggregated. This sections are named, the section name corresponds to the covered logical interface.

Example:

config 'interface' 'lan' option 'enabled' '1' option 'sla_id' '0' option 'sla_len' '8'

• lan specifies that this section belongs to the LAN interface
• sla_id 0 selects the 1st subnet out of the delegated prefix
• sla_len 8 defines that the received prefix is expected to be 56 bits in size ( 64 - 8 = 56)

The valid options of this section are listed blow.

Name	Type	Required	Default	Description
enabled	boolean	no	0	Specifies whether a prefix should be added on this interface
sla_id	integer	yes	(none)	Specifies the site level aggregator identifier (selects the subnet out of the delegated prefix)
sla_len	integer	yes	(none)	Specifies the site level aggregator length which is the difference of 64 and the delegated prefix size, e.g. /64 minus /56 from ISP = 8

Example

This example requests a /56 sized prefix and DNS servers on wan and configures two /64 subnets out of the prefix on lan and loopback. The loopback interface gets the first subnet assigned, lan the second.

config 'dhcp6c' 'basic' option 'enabled' '1' option 'interface' 'wan' option 'pd' '1' option 'domain_name_servers' '1' option 'script' '/usr/bin/dhcp6c-state' config 'interface' 'loopback' option 'enabled' '1' option 'sla_id' '0' option 'sla_len' '8' config 'interface' 'lan' option 'enabled' '1' option 'sla_id' '1' option 'sla_len' '8'

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dhcp6c(8) - Linux man page

Name

dhcp6c - DHCPv6 client daemon

Synopsis

dhcp6c [ -dDf ] [ -r all | <addresses...> ] [ -R <addresses...> ] [ -c pathspec ] [ -I ] <interface>

Description

 

dhcp6c is an implementation of the DHCPv6 client.

Using DHCPv6 messages and DHCPv6 options, dhcp6c is used to request and configure IPv6 addresses and host network configuration information (e.g., DNS) for a network interface from the DHCPv6 server. It can also be used as a requesting router to request and configure Prefix Delegation for a subnet.

The assigned IPv6 addresses and prefixes are saved as /var/lib/dhcpv6/client6.leasesXXXXXX; this file is used to request the same addresses and prefixes from the DHCPv6 server. Each dhcp6c client has a client DHCP Unique Identifier (DUID); the DUID file is saved as /var/lib/dhcpv6/dhcp6c_duid. The dhcp6c client configuration is defined in /etc/dhcp6c.conf.

Options

-c pathspec

Specifies

the configuration file for dhcp6c

-d

Enables dhcp6c to print debugging messages.

-D

Enables dhcp6c to print verbose debugging messages.

-f

Enables dhcp6c to work as a foreground application. This option is helpful for debugging.

-I

Allows dhcp6c to request network information only. Do not configure the interface.

-r all | <addresses...>

Allows dhcp6c to release the addresses specified. This option is used only when releasing addresses explicitly.

-R <addresses...>

Allows dhcp6c to request the specified addresses.

Files

/etc/dhcp6c.conf

Contains DHCPv6 client configuration information.

/var/lib/dhcpv6/dhcp6c_duid

Contains DHCPv6 client DUID.

/var/lib/dhcpv6/client6_leasesXXXXXX

Contains DHCPv6 client assigned IPv6 addresses and prefixes.

Errors

Check /var/log/messages if there are errors.