/etc/rtadvd.conf

Configuration file for router advertisement daemon

Name:

/etc/rtadvd.conf

Description:

This file describes how the router advertisement packet must be constructed for each of the interfaces.

Each line in the file describes a network interface. Fields are separated by a colon (:), and each field contains one capability description. Lines may be concatenated by using the backslash (\) character. The comment marker is the pound sign (#).

Capabilities

Capabilities describe the value to be filled into ICMPv6 router advertisement messages and to control rtadvd behavior. Therefore, you are encouraged to read IETF neighbor discovery documents if you would like to modify the sample configuration file.


Note: Almost all items have default values. If you omit an item, the default value of the item will be used.

The following two items control the interval of sending router advertisements:

maxinterval

This is the maximum time (in seconds) allowed between sending unsolicited multicast router advertisements. The value must be be no less than 4 seconds and no greater than 1800 seconds. The default value is 600.

mininterval

The minimum time (in seconds) allowed between sending unsolicited multicast router advertisements. Its value must be no less than 3 seconds and no greater than .75 * the value of maxinterval. The default value is one third of the value of maxinterval.

The following items are for ICMPv6 router advertisement message header.

chlim

The number value for Cur Hop Limit field. The default value is 64.

raflags

A number specifying the Flags field in router advertisement message header. Bit 7 (0x80) means Managed address configuration flag bit, and Bit 6 (0x40) means Other stateful configuration flag bit. The default value is 0.

rltime

The number of seconds specifying the Router lifetime field. Its value must be no greater than 3600000. The default value is 1800.

rtime

The number of milliseconds specifying the Reachable time field. The default value is 0, which means unspecified by this router.

retrans

The number of milliseconds specifying the Retrans Timer field. The default value is 0, which means unspecified by this router.

The following items are for ICMPv6 prefix information option, which will be attached to router advertisement header.

addrs

The number of prefixes. Its default is 0, so it must explicitly be set to positive values if you want to specify any prefix information option. If its value is 0, rtadvd looks up the system routing table and advertise the prefixes corresponding to interface routes on the interface. If its value is more than 1, you must specify the index of the prefix for each item below. Indices vary from 0 to N-1, where N is the value of addrs. Each index shall follow the name of each item, e.g. prefixlen2.

prefixlen

A number specifying the Prefix length field. The default value is 64.

pinfoflags

A number specifying the Flags field in prefix information option. Bit 7 (0x80) means On-link flag bit, and Bit 6 (0x40) means Autonomous address-configuration flag bit. The default value is 0xc0, i.e. both bits are set.

addr

A string specifying the address filled into Prefix field. Since the colon character (:) is used for IPv6 numeric address, the field must be quoted by the double-quote character " ". This field cannot be omitted if the value of addrs is more than 0.

vltime

The number of seconds specifying the Valid lifetime field. The default value is 2592000 (30 days).

pltime

The number of seconds specifying the Preferred lifetime field. The default value is 604800 (7 days).

The following items are for ICMPv6 MTU option, which will be attached to router advertisement header.

mtu

A number or string that specifies the MTU (maximum transmission unit) field. If 0 is specified, it means that the option will not be included. The default value is 0. If the special string "auto" is specified for this item, MTU option will be included and its value will be set to the interface MTU automatically.

The following item controls ICMPv6 source link-layer address option, which will be attached to router advertisement header.

nolladdr

A boolean expression. By default (if nolladdr is not specified), rtadvd will try to get link-layer address for the interface from the kernel, and attach that in source link-layer address option. If this capability exists, rtadvd(8) will not attach source link-layer address option to router advertisement packets.

Examples:

#
# common definitions.
#
default:\
        :raflags#0:rltime#3600:\
        :pinfoflags#64:vltime#360000:pltime#360000:mtu#1500:
ether:\
        :mtu#1280:tc=default:

#
# interfaces.
#
ef0:\
        :addrs#1:\
        :addr="3ffe:501:4819:1000::":tc=ether:
ef1:\
        :addrs#2:addr0="3ffe:501:4819:2000::":\
        :addr1="3ffe:501:4819:3000::":tc=ether:

See also:

rtadvd, rtsold

Thomas Narten, Erik Nordmark and W. A. Simpson, Neighbor Discovery for IP version 6 (IPv6), RFC 2461.