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RTADVD.CONF(5)		       File Formats Manual		  RTADVD.CONF(5)

NAME
     rtadvd.conf -- config file for router advertisement daemon

DESCRIPTION
     This  file  describes  how  the  router  advertisement packets must be con-
     structed for each of the interfaces.

     As described in rtadvd(8), you do not have to set this  configuration  file
     up  at all, unless you need some special configurations.  You may even omit
     the file as a whole.  In such cases, the rtadvd daemon  will  automatically
     configure itself using default values specified in the specification.

     It  obeys	the  famous  termcap(5)  file format.  Each line in the file de-
     scribes a network interface.  Fields are separated by a  colon  (`:'),  and
     each  field contains one capability description.  Lines may be concatenated
     by the `\' character.  The comment marker is the `#' character.

CAPABILITIES
     Capabilities describe the value to be filled into ICMPv6 router  advertise-
     ment  messages  and  to control rtadvd(8) behavior.  Therefore, you are en-
     couraged to read IETF neighbor discovery documents if  you  would	like  to
     modify the sample configuration file.

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

     There are two items which control the interval of sending router advertise-
     ments.  These items can be omitted, then rtadvd will use the  default  val-
     ues.

     maxinterval
	     (num)  The  maximum time allowed between sending unsolicited multi-
	     cast router advertisements (unit: seconds).  The default  value  is
	     600.   Its value must be no less than 4 seconds and no greater than
	     1800 seconds.

     mininterval
	     (num) The minimum time allowed between sending  unsolicited  multi-
	     cast  router  advertisements (unit: seconds).  The default value is
	     the one third of value of maxinterval.  Its value must be	no  less
	     than 3 seconds and no greater than .75 * the value of maxinterval.

     The  following  items  are  for ICMPv6 router advertisement message header.
     These items can be omitted, then rtadvd will use the default values.

     chlim   (num) The value for Cur Hop Limit field.  The default value is 64.

     raflags
	     (str or num) A 8-bit flags field in  router  advertisement  message
	     header.   This  field  can  be specified either as a case-sensitive
	     string or as an integer.  A string consists of characters	each  of
	     which  corresponds  to a particular flag bit(s).  An integer should
	     be the logical OR of all enabled bits.  Bit 7 ('m' or  0x80)  means
	     Managed  address  configuration  flag  bit, and Bit 6 ('o' or 0x40)
	     means Other stateful configuration flag bit.  Bit 4 (0x10) and  Bit
	     3	(0x08)	are  used to encode router preference.	Bits 01 (or 'h')
	     means high, 00 means medium, and 11 (or 'l') means low.  Bits 10 is
	     reserved, and must not be specified.   There  is  no  character  to
	     specify the medium preference explicitly.	The default value of the
	     entire flag is 0 (or a null string,) which means no additional con-
	     figuration methods, and the medium router preference.

     rltime  (num) Router lifetime field (unit: seconds).  The value must be ei-
	     ther  zero  or  between  the  value  of maxinterval and 9000.  When
	     rtadvd runs on a host, this value must explicitly set 0 on all  the
	     advertising  interfaces  as  described  in  rtadvd(8).  The default
	     value is 1800.

     rtime   (num) Reachable time field (unit: milliseconds).  The default value
	     is 0, which means unspecified by this router.

     retrans
	     (num) Retrans Timer field (unit: milliseconds).  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.	These items can be omitted, then
     rtadvd will automatically get appropriate prefixes from the kernel's  rout-
     ing  table,  and  advertise the prefixes with the default parameters.  Key-
     words other than clockskew and noifprefix can be augmented with  a  number,
     like "prefix2", to specify multiple prefixes.

     noifprefix
	     (bool) Specifies no prefix on the network interfaces will be adver-
	     tised.   By  default  rtadvd automatically gathers on-link prefixes
	     from all  of  the	network  interfaces  and  advertise  them.   The
	     noifprefix  disables  that  behavior.   If this is specified and no
	     addr keyword is specified, no prefix information option will be in-
	     cluded in the message.

     clockskew
	     (num) Time skew to adjust link propagation delays and  clock  skews
	     between routers on the link (unit: seconds).  This value is used in
	     consistency  check  for  locally-configured  and  advertised prefix
	     lifetimes, and has its meaning when the local router  configures  a
	     prefix  on  the  link with a lifetime that decrements in real time.
	     If the value is 0, it means the consistency check will  be  skipped
	     for such prefixes.  The default value is 0.

     prefixlen
	     (num) Prefix length field.  The default value is 64.

     pinfoflags
	     (str  or  num)  A	8-bit  flags field in prefix information option.
	     This field can be specified either as a case-sensitive string or as
	     an integer.  A string consists of characters each of  which  corre-
	     sponds to a particular flag bit(s).  An integer should be the logi-
	     cal OR of all enabled bits.  Bit 7 ('l' or 0x80) means On-link flag
	     bit, and Bit 6 ('a' or 0x40) means Autonomous address-configuration
	     flag  bit.   The default value is "la" or 0xc0, i.e., both bits are
	     set.

     addr    (str) The address filled into Prefix field.  Since ":" is used  for
	     termcap(5)  file  format as well as IPv6 numeric address, the field
	     MUST be quoted by doublequote character.

     vltime  (num) Valid lifetime field (unit: seconds).  The default  value  is
	     2592000 (30 days).

     vltimedecr
	     (bool) This item means the advertised valid lifetime will decrement
	     in real time, which is disabled by default.

     pltime  (num)  Preferred lifetime field (unit: seconds).  The default value
	     is 604800 (7 days).

     pltimedecr
	     (bool) This item  means  the  advertised  preferred  lifetime  will
	     decrement in real time, which is disabled by default.

     The  following  item  is  for  ICMPv6 MTU option, which will be attached to
     router advertisement header.  This item can be omitted,  then  rtadvd  will
     use the default value.

     mtu     (num or str) MTU (maximum transmission unit) field.  If 0 is speci-
	     fied,  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.  As noted above, you can
     just omit the item, then rtadvd will use the default value.

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

     The following item controls ICMPv6 home agent information option, which was
     defined with mobile IPv6 support.	It will be attached to router advertise-
     ment header just like other options do.

     hapref  (num)  Specifies home agent preference.  If set to non-zero, hatime
	     must be present as well.

     hatime  (num) Specifies home agent lifetime.

     When mobile IPv6 support is turned on for rtadvd(8), advertisement interval
     option will be attached to  router  advertisement	packet,  by  configuring
     maxinterval explicitly.

     The  following items are for ICMPv6 route information option, which will be
     attached to router advertisement header.  These items are	optional.   Each
     items  can  be  augmented	with number, like "rtplen2", to specify multiple
     routes.

     rtprefix
	     (str) The prefix filled into the Prefix field of route  information
	     option.   Since  ":"  is used for termcap(5) file format as well as
	     IPv6 numeric address, the field MUST be quoted by doublequote char-
	     acter.

     rtplen  (num) Prefix length field in route information option.  The default
	     value is 64.

     rtflags
	     (str or num) A 8-bit flags field in route information option.  Cur-
	     rently only the preference values are  defined.   The  notation  is
	     same  as  that of the raflags field.  Bit 4 (0x10) and Bit 3 (0x08)
	     are used to encode the route preference for the route.  The default
	     value is 0x00, i.e., medium preference.

     rtltime
	     (num) route lifetime field in  route  information	option.   (unit:
	     seconds).	 Since	the  specification  does  not define the default
	     value of this item, the value for this item should be specified  by
	     hand.  However, rtadvd allows this item to be unspecified, and uses
	     the  router  lifetime as the default value in such a case, just for
	     compatibility with an old version of the program.

     In the above list, each keyword beginning with "rt" could be replaced  with
     the  one beginning with "rtr" for backward compatibility reason.  For exam-
     ple, rtrplen is accepted instead of rtplen.  However, keywords  that  start
     with "rtr" have basically been obsoleted, and should not be used any more.

     The  following  items  are  for  ICMPv6 Recursive DNS Server Option and DNS
     Search List Option (RFC 6106), which will be attached to router  advertise-
     ment header.  These items are optional.

     rdnss   (str)  The  IPv6 address of one or more recursive DNS servers.  The
	     argument must be inside double quotes.  Multiple DNS servers can be
	     specified in a comma-separated string.  If different lifetimes  are
	     needed  for different servers, separate entries can be given by us-
	     ing rdnss, rdnss0, rdnss1, rdnss2 ...  options  with  corresponding
	     rdnssltime,  rdnssltime0,	rdnssltime1,  rdnssltime2  ...	entries.
	     Note that the maximum number of servers  depends  on  the	receiver
	     side.  See also resolver(5) manual page for resolver implementation
	     in FreeBSD.

     rdnssltime
	     The lifetime of the rdnss DNS server entries.  The default value is
	     3/2 of the interval time.

     dnssl   (str)  One or more domain names in a comma-separated string.  These
	     domain names will be used when making DNS queries on  a  non-fully-
	     qualified	domain name.  If different lifetimes are needed for dif-
	     ferent domains, separate entries  can  be	given  by  using  dnssl,
	     dnssl0,  dnssl1,  dnssl2 ... options with corresponding dnsslltime,
	     dnsslltime0, dnsslltime1, dnsslltime2 ... entries.  Note  that  the
	     maximum number of names depends on the receiver side.  See also re-
	     solver(5) manual page for resolver implementation in FreeBSD.

     dnsslltime
	     The  lifetime  of	the  dnssl DNS search list entries.  The default
	     value is 3/2 of the interval time.

     The following items are for PREF64 discovery (RFC 8781), which will  adver-
     tise the network's NAT64 prefix to clients.  These items are optional.

     pref64  (str) The prefix to advertise in the PREF64 option.

     pref64len
	     (num)  The  length  of the PREF64 prefix.	This must be 96, 64, 56,
	     48, 40, or 32.  If not specified, the default is 96.

     pref64lifetime
	     (num) The prefix lifetime to advertise in the PREF64 option.   This
	     should  be  at  least  as	long  as  the RA lifetime, but cannot be
	     greater than 65528.  If not specified, the default is the RA  life-
	     time, or 65528, whichever is lower.

     You can also refer one line from another by using tc capability.  See term-
     cap(5) for details on the capability.

EXAMPLES
     As  presented  above,  all of the advertised parameters have default values
     defined in specifications, and hence you usually do not have to set them by
     hand, unless you need special non-default values.	It can cause  interoper-
     ability problem if you use an ill-configured parameter.

     To override a configuration parameter, you can specify the parameter alone.
     With  the	following configuration, rtadvd(8) overrides the router lifetime
     parameter for the ne0 interface.

	   ne0:\
		   :rltime#0:

     The following example manually configures prefixes advertised from the  ef0
     interface.  The configuration must be used with the -s option to rtadvd(8).

	   ef0:\
		   :addr="2001:db8:ffff:1000::":prefixlen#64:

     The  following  example  configures  the  wlan0  interface and adds two DNS
     servers and a DNS domain search options using the default	option	lifetime
     values.

	   wlan0:\
		   :addr="2001:db8:ffff:1000::":prefixlen#64:\
		   :rdnss="2001:db8:ffff::10,2001:db8:ffff::2:43":\
		   :dnssl="example.com":

     The  following  example  presents the default values in an explicit manner.
     The configuration is provided just for reference purposes; YOU DO NOT  NEED
     TO HAVE IT AT ALL.

	   default:\
		   :chlim#64:raflags#0:rltime#1800:rtime#0:retrans#0:\
		   :pinfoflags="la":vltime#2592000:pltime#604800:mtu#0:
	   ef0:\
		   :addr="2001:db8:ffff:1000::":prefixlen#64:tc=default:

SEE ALSO
     resolver(5), termcap(5), rtadvd(8), rtsol(8)

     Thomas  Narten,  Erik Nordmark, W. A. Simpson, and Hesham Soliman, Neighbor
     Discovery for IP version 6 (IPv6), RFC 4861.

     Thomas Narten, Erik Nordmark, and W. A. Simpson, Neighbor Discovery for  IP
     version 6 (IPv6), RFC 2461 (obsoleted by RFC 4861).

     Richard Draves, Default Router Preferences and More-Specific Routes, draft-
     ietf-ipngwg-router-selection-xx.txt.

     J.  Jeong,  S. Park, L. Beloeil, and S. Madanapalli, IPv6 Router Advertise-
     ment Options for DNS Configuration, RFC 6106.

HISTORY
     The rtadvd(8) and the configuration file rtadvd.conf first appeared in WIDE
     Hydrangea IPv6 protocol stack kit.

FreeBSD ports 15.quarterly	  June 4, 2011			  RTADVD.CONF(5)

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