radvd.conf  -  configuration file of the router advertise­
       ment daemon radvd


DESCRIPTION

       This file describes the information which is  included  in
       the router advertisement (RA) of a specific interface.

       The file contains one or more interface definitions of the
       form:

       interface name {
            list of interface specific options
            list of prefix definitions
       };

       All the possible interface specific options  are  detailed
       below.  Each option has to be terminated by a semicolon.

       Prefix definitions are of the form:

       prefix prefix/length {
            list of prefix specific options
       };

       Prefix  can be network prefix or the address of the infer­
       face.  The address of interface should be used when  using
       Mobile IPv6 extensions.

       All  the  possible  prefix  specific options are described
       below.  Each option has to be terminated by a semicolon.

       Decimal values are allowed only for MaxRtrAdvInterval  and
       MinRtrAdvInterval.   Decimal  values  should  be used only
       when using Mobile IPv6 extensions.


INTERFACE SPECIFIC OPTIONS

       AdvSendAdvert on|off

              A flag indicating whether or not the  router  sends
              periodic  router  advertisements  and  responds  to
              router solicitations.

              This option no longer has to  be  specified  first,
              but  it  needs  to be on to enable advertisement on
              this interface.

       MaxRtrAdvInterval seconds

              The maximum  time  allowed  between  sending  unso­
              licited  multicast  router  advertisements from the
              interface, in seconds.

              1800 seconds.

              Minimum when using Mobile IPv6 extensions: 1.5.

              Default: 600 seconds

       MinRtrAdvInterval seconds

              The  minimum  time  allowed  between  sending unso­
              licited multicast router  advertisements  from  the
              interface, in seconds.

              Must  be no less than 3 seconds and no greater than
              0.75 * MaxRtrAdvInterval.

              Minimum when using Mobile IPv6 extensions: 0.5.

              Default: 0.33 * MaxRtrAdvInterval

       AdvManagedFlag on|off

              When set, hosts  use  the  administered  (stateful)
              protocol  for address autoconfiguration in addition
              to any  addresses  autoconfigured  using  stateless
              address autoconfiguration.  The use of this flag is
              described in RFC 2462.

              Default: off

       AdvOtherConfigFlag on|off

              When set, hosts  use  the  administered  (stateful)
              protocol   for  autoconfiguration  of  other  (non-
              address) information.  The  use  of  this  flag  is
              described in RFC 2462.

              Default: off

       AdvLinkMTU integer

              The  MTU  option  is  used in  router advertisement
              messages to insure that all nodes on a link use the
              same MTU value in those cases where the link MTU is
              not well known.

              If specified, i.e. not 0, must be geater  than  576
              and not be greater than the maximum MTU allowed for
              this link (e.g. ethernet has a maximum MTU of 1500.
              See RFC 2464).


       AdvReachableTime milliseconds

              The  time,  in  milliseconds, that a node assumes a
              neighbor  is  reachable  after  having  received  a
              reachability  confirmation.   Used  by the Neighbor
              Unreachability Detection algorithm (see Section 7.3
              of  RFC  2461).   A value of zero means unspecified
              (by this router).

              Must be no greater than 3,600,000  milliseconds  (1
              hour).

              Default: 0

       AdvRetransTimer milliseconds

              The  time,  in  milliseconds, between retransmitted
              Neighbor Solicitation messages.   Used  by  address
              resolution  and  the Neighbor Unreachability Detec­
              tion algorithm (see Sections 7.2  and  7.3  of  RFC
              2461).   A value of zero means unspecified (by this
              router).

              Default: 0

       AdvCurHopLimit integer

              The default value that should be placed in the  Hop
              Count field of the IP header for outgoing (unicast)
              IP packets.  The value should be set to the current
              diameter  of  the  Internet.   The value zero means
              unspecified (by this router).

              Default: 64

       AdvDefaultLifetime seconds

              The lifetime associated with the default router  in
              units of seconds.  The maximum value corresponds to
              18.2 hours.  A lifetime of  0  indicates  that  the
              router  is  not  a  default  router  and should not
              appear on the  default  router  list.   The  router
              lifetime applies only to the router's usefulness as
              a default router; it does not apply to  information
              contained  in  other  message  fields  or  options.
              Options that need time limits for their information
              include their own lifetime fields.

              and 9000 seconds.

              Default: 3 * MaxRtrAdvInterval

       AdvSourceLLAddress on|off

              When set, the link-layer address  of  the  outgoing
              interface is included in the RA.

              Default: on

       AdvHomeAgentFlag on|off

              When  set, indicates that sending router is able to
              serve as Mobile IPv6 Home Agent.  When set, minimum
              limits  specified by Mobile IPv6 are used for MinR­
              trAdvInterval and MaxRtrAdvInterval.

              Default: off

       AdvHomeAgentInfo on|off

              When set, Home Agent Information Option  (specified
              by  Mobile  IPv6)  is included in Router Advertise­
              ments.  AdvHomeAgentFlag  must  also  be  set  when
              using this option.

              Default: off

       HomeAgentLifetime seconds

              The length of time in seconds (relative to the time
              the packet is sent) that  the  router  is  offering
              Mobile  IPv6  Home  Agent services.  A value 0 must
              not be used.  The maximum lifetime is 65520 seconds
              (18.2  hours).  This option is ignored, if AdvHome­
              AgentInfo is not set.

              If both HomeAgentLifetime  and  HomeAgentPreference
              are  set to their default values, Home Agent Infor­
              mation Option will not be sent.

              Default: AdvDefaultLifetime

       HomeAgentPreference integer

              The preference for  the  Home  Agent  sending  this
              Router   Advertisement.    Values  greater  than  0

              than  0  indicate less preferable Home Agent.  This
              option is ignored, if AdvHomeAgentInfo is not  set.

              If  both  HomeAgentLifetime and HomeAgentPreference
              are set to their default values, Home Agent  Infor­
              mation Option will not be sent.

              Default: 0

       AdvIntervalOpt on|off

              When  set, Advertisement Interval Option (specified
              by Mobile IPv6) is included  in  Router  Advertise­
              ments.   When  set,  minimum  limits  specified  by
              Mobile IPv6  are  used  for  MinRtrAdvInterval  and
              MaxRtrAdvInterval.

              Default: off


PREFIX SPECIFIC OPTIONS

       AdvOnLink on|off

              When  set,  indicates  that this prefix can be used
              for on-link determination.  When not set the adver­
              tisement  makes  no statement about on-link or off-
              link properties of the prefix.  For  instance,  the
              prefix might be used for address configuration with
              some of the addresses belonging to the prefix being
              on-link and others being off-link.

              Default: on

       AdvAutonomous on|off

              When  set,  indicates  that this prefix can be used
              for autonomous address configuration  as  specified
              in RFC 2462.

              Default: on

       AdvRouterAddr on|off

              When  set,  indicates that the address of interface
              is sent instead of network prefix, as  is  required
              by Mobile IPv6.  When set, minimum limits specified
              by Mobile IPv6 are used for  MinRtrAdvInterval  and
              MaxRtrAdvInterval.

              Default: off


              The length of time in seconds (relative to the time
              the packet is sent) that the prefix  is  valid  for
              the purpose of on-link determination.  The symbolic
              value infinity represents infinity (i.e. a value of
              all  one bits (0xffffffff)).  The valid lifetime is
              also used by RFC 2462.

              Default: infinity

       AdvPreferredLifetime seconds|infinity

              The length of time in seconds (relative to the time
              the  packet  is sent) that addresses generated from
              the prefix via stateless address  autoconfiguration
              remain preferred.  The symbolic value infinity rep­
              resents infinity (i.e. a  value  of  all  one  bits
              (0xffffffff)).  See RFC 2462.

              Default: 604800 seconds (7 days)

       Base6to4Interface name

              If  this  option  is specified, this prefix will be
              combined with the IPv4 address of interface name to
              produce  a  valid 6to4 prefix. The first 16 bits of
              this prefix will be replaced by 2002 and  the  next
              32 bits of this prefix will be replaced by the IPv4
              address assigned to interface name at configuration
              time.  The remaining 80 bits of the prefix (includ­
              ing the SLA ID) will be advertised as specified  in
              the  configuration  file.  See the next section for
              an example.

              If interface name is not available at configuration
              time, a warning will be written to the log and this
              prefix will be disabled until  radvd  is  reconfig­
              ured.

              This  option  enables  systems  with  dynamic  IPv4
              addresses to update their advertised 6to4  prefixes
              simply by restarting radvd or sending a SIGHUP sig­
              nal to cause radvd to reconfigure itself.

              Note that 6to4 prefixes derived  from  dynamically-
              assigned IPv4 addresses should be advertised with a
              significantly  shorter  lifetime  (see   the   Adv­
              ValidLifetime and AdvPreferredLifetime options).

              For more information on 6to4, see RFC 3056.



EXAMPLES

       interface eth0
       {
               AdvSendAdvert on;
               prefix fec0:0:0:1::/64
               {
                       AdvOnLink on;
                       AdvAutonomous on;
               };
       };

       It  says that router advertisement daemon should advertise
       (AdvSendAdvert on;) the prefix fec0:0:0:1::  which  has  a
       lenght  of  64  on  the  interface  eth0.  Also the prefix
       should be marked as autonomous (AdvAutonomous on;) and  as
       on-link  (AdvOnLink  on;).  All the other options are left
       on their default values.

       To support movement detection of Mobile IPv6 Mobile Nodes,
       the address of interface should be used instead of network
       prefix:

       interface eth0
       {
               AdvSendAdvert on;
               prefix fec0:0:0:1::4/64
               {
                       AdvOnLink on;
                       AdvAutonomous on;
                       AdvRouterAddr on;
               };
       };

       For 6to4 support, include the Base6to4Interface option  in
       each  prefix  section.  When using a dynamic IPv4 address,
       set small prefix lifetimes to prevent hosts from retaining
       unreachable  prefixes  after  a  new IPv4 address has been
       assigned.

       interface eth0
       {
               AdvSendAdvert on;

               # Advertise at least every 30 seconds
               MaxRtrAdvInterval 30;

               prefix 0:0:0:5678::/64
               {
                       AdvOnLink on;
                       AdvAutonomous on;
                       Base6to4Interface ppp0;

                       AdvDefaultLifetime 300;
                       AdvPreferredLifetime 120;
               };
       };

       Since 6to4 is enabled, the prefix will  be  advertised  as
       2002:WWXX:YYZZ:5678::/64,  where  WW.XX.YY.ZZ  is the IPv4
       address of ppp0 at configuration time. (IPv6 addresses are
       written  in hexadecimal whereas IPv4 addresses are written
       in decimal, so the IPv4 address WW.XX.YY.ZZ  in  the  6to4
       prefix will be represented in hex.)


FILES

       /usr/sbin/radvd
       /etc/radvd.conf
       /var/run/radvd/radvd.pid
       /var/log/radvd.log


CREDIT

       The description of the different flags and variables is in
       large parts taken from RFC 2461.


RFCS

       Narten, T., E. Nordmark, W. Simpson,  "Neighbor  Discovery
       for IP Version 6 (IPv6)", RFC 2461, December 1998

       Thomson,  S., and T. Narten, "IPv6 Stateless Address Auto­
       configuration", RFC 2462, December 1998.

       Deering,  S.,  and  R.  Hinden,  Editors,  "IP  Version  6
       Addressing Architecture", RFC 2373, July 1998.

       Conta,  A., and S. Deering, "Internet Control Message Pro­
       tocol  (ICMPv6)  for  the  Internet  Protocol  Version   6
       (IPv6)", RFC 2463, December 1998.

       Crawford,  M., "Transmission of IPv6 Packets over Ethernet
       Networks", RFC 2464, December 1998.

       Carpenter B., Moore K., "Connection of  IPv6  Domains  via
       IPv4  Clouds",  RFC  3056, February 2001. (6to4 specifica­
       tion)


SEE ALSO

       radvd(8), radvdump(8)


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