RAD.CONF(5)

NAME
rad.conf - router advertisement daemon configuration file

DESCRIPTION
The rad(8) daemon is an IPv6 router advertisement daemon.

The rad.conf config file is divided into the following main sections:

Macros
    Definitions of variables that can be used later, simplifying the configuration file.

Global configuration
    Global settings for rad(8). These are used as default values for interface definitions and can be overwritten in an interface block.

Interfaces
    rad(8) sends IPv6 router advertisement messages. This section defines on which interfaces to advertise prefix information and their associated parameters.

Additional configuration files can be included with the include keyword.

  Macros
A macro is defined with a command of the form name=value. The macro name can contain letters, digits, and underscores and cannot be a reserved word (for example, interface). Within unquoted arguments, the string $name is later expanded to value.

  Global configuration
The global configuration section sets defaults for router advertisement messages. These can be overwritten in interface blocks.

default router (yes|no)
    Act as a default router or not. The default is yes.

dns {option ...}
    Add a DNS router advertisement option to communicate network provided nameservers. In a dns block, a search option or at least one nameserver option is required, whereas specifying the lifetime is optional:

    lifetime seconds
        The number of seconds the dns options are valid after receiving a router advertisement message. The default is 3600 seconds.

    nameserver (address|{address ...})
        IPv6 address or list of IPv6 addresses of DNS name servers.

    search (domain|{domain ...})
        Domain or list of domains for the resolv.conf(5) search list.

hop limit hops
    Specify the diameter of the internet. The default is 0, meaning unspecified by this router.

managed address configuration (yes|no)
    If set to yes, indicate that stateless address configuration prefixes are not available and hosts should consult DHCPv6. The default is no.

mtu bytes
    The MTU option is used in Router Advertisement messages to ensure that all nodes on a link use the same MTU value in those cases where the link MTU is not well known. The default is 0, meaning unspecified by this router.

nat64 prefix prefix [{option ...}]
    Add a PREF64 router advertisement option to communicate prefixes used for Network Address and Protocol Translation from IPv6 to IPv4 (NAT64). If prefix is specified without a prefix length, its default is 64.

    nat64 prefix options are as follows:

    lifetime seconds
        The number of seconds the nat64 prefix option is valid after receiving a router advertisement message. A value of zero indicates to not use the prefix anymore. The maximum is 65528 seconds. The default is 3600 seconds.

other configuration (yes|no)
    If set to yes, hosts should consult DHCPv6 for additional configuration like NTP servers or DNS name servers. The default is no.

router lifetime seconds
    The number of seconds this router is a valid default router after receiving a router advertisement message. The default is 3600 seconds.

router preference (high|medium|low)
    Indicate whether to prefer this router over other default routers. The default is medium.

reachable time number
    The time, in milliseconds, that a node assumes a neighbor is reachable. The default is 0, meaning unspecified by this router. This option is ignored by slaacd(8) and cannot be set on OpenBSD IPv6 hosts.

retrans timer number
    The time, in milliseconds, between retransmitted Neighbor Solicitation messages. The default is 0, meaning unspecified by this router. This option is ignored by slaacd(8) and cannot be set on OpenBSD IPv6 hosts.

source link-layer address (yes|no)
    Add a source link-layer address option to router advertisement messages, to communicate the link-layer address of the sending interface. The default is yes.

  Interfaces
This section contains a list of interfaces or interface groups to send advertisements on. At least one interface is required.

interface name [{prefix ...}]
    Options set in the global section can be overwritten inside an interface block. In addition an interface block can contain a list of prefixes:

    [no] auto prefix [{option ...}]
    prefix prefix [{option ...}]
        The default is to discover prefixes to announce by inspecting the IPv6 addresses configured on an interface. This can be disabled with no auto prefix. If prefix is specified without a prefix length, its default is 64.

        prefix options are as follows:

        autonomous address-configuration (yes|no)
            This prefix can be used to generate IPv6 addresses. The default is yes.

        on-link (yes|no)
            This prefix is considered on-link. The default is yes.

        preferred lifetime seconds
            The preferred lifetime (pltime) in seconds for addresses generated from this prefix. The default is 2700. This option is ignored if the prefix is discovered from a network interface and it has a lower preferred lifetime.

        valid lifetime seconds
            The valid lifetime (vltime) in seconds for addresses generated from this prefix. The default is 3600. This option is ignored if the prefix is discovered from a network interface and it has a lower valid lifetime.

FILES
/etc/rad.conf
    rad(8) configuration file.
/etc/examples/rad.conf
    Example configuration file.

EXAMPLES
With the following example configuration, rad(8) will pick a prefix from the ix1 interface and send router advertisements on it:

    interface ix1

SEE ALSO
ractl(8), rad(8), rc.conf.local(8)

HISTORY
The rad.conf file format first appeared in OpenBSD 6.4.