Provided by: radvd_1.6-1_i386 bug

NAME

       radvd.conf  -  configuration  file  of  the router advertisement 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
            list of clients (IPv6 addresses) to advertise to
            list of route definitions
            list of RDNSS 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  inferface.   The
       address  of interface should be used when using Mobile IPv6 extensions.

       Special prefix "::/64" is also  supported  on  systems  that  implement
       getifaddrs()  (on  other  systems,  configuration  activation fails and
       radvd exits).  When configured, radvd picks one  non-link-local  prefix
       assigned  to  the  interface  and  starts  advertising it.  This may be
       applicable in  non-6to4  scenarios  where  the  upstream  prefix  might
       change.   This  option  is  incompatible with Base6to4Interface option.
       AdvRouterAddr option is always enabled when this configuration is used.

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

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

       Route definitions are of the form:

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

       The prefix of a route definition should be network prefix;  it  can  be
       used to advertise more specific routes to the hosts.

       RDNSS (Recursive DNS server) definitions are of the form:

       RDNSS ip [ip] [ip] {
            list of rdnss specific options
       };

       By  default  radvd will send route advertisements so that every node on
       the link can use them.  The list of clients (IPv6 address) to advertise
       to,  and  accept  route solicitations from can be configured.  If done,
       radvd does not send send messages to the multicast addresses but to the
       configured  unicast addresses only.  Solicitations from other addresses
       are refused.  This is similar  to  UnicastOnly  but  includes  periodic
       messages  and  incoming  client  access  configuration.   See  examples
       section for a use case of this.

       The definitions are of the form:

       clients {
               list of IPv6 addresses
       };

INTERFACE SPECIFIC OPTIONS

       IgnoreIfMissing on|off

              A flag indicating whether or not the interface is ignored if  it
              does not exist at start-up.  By default, radvd exits.

              This  is useful for dynamic interfaces which are not active when
              radvd starts or which are dynamically  disabled  and  re-enabled
              during the time radvd runs.

              Current   versions  of  radvd  automatically  try  to  re-enable
              interfaces.

              Enabling IgnoreIfMissing also quenches certain warnings  in  log
              messages relating to missing interfaces.

              Default: off

       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.

              Default: off

       UnicastOnly on|off

              Indicates  that  the  interface link type only supports unicast.
              This will prevent unsolicited advertisements  from  being  sent,
              and  will  cause  solicited  advertisements to be unicast to the
              soliciting node.  This option is  necessary  for  non-broadcast,
              multiple-access links, such as ISATAP.

              Default: off

       MaxRtrAdvInterval seconds

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

              Must be no less than 4 seconds and no greater than 1800 seconds.

              Minimum when using Mobile IPv6 extensions: 0.07.

              For  values  less  than  0.2  seconds,  0.02 seconds is added to
              account for scheduling granularities as specified in RFC3775.

              Default: 600 seconds

       MinRtrAdvInterval seconds

              The minimum time allowed between sending  unsolicited  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: 0.03.

              Default: 0.33 * MaxRtrAdvInterval

       MinDelayBetweenRAs seconds

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

              This applies to solicited multicast RAs.  This is defined as the
              protocol  constant  MIN_DELAY_BETWEEN_RAS  in  RFC4861.    MIPv6
              redefines this parameter to have a minimum of 0.03 seconds.

              Minimum when using Mobile IPv6 extensions: 0.03.

              Default: 3

       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 4862.

              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 4862.

              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 not be smaller than 1280 and  not
              greater  than  the  maximum  MTU  allowed  for  this  link (e.g.
              ethernet has a maximum MTU of 1500. See RFC 4864).

              Default: 0

       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 4861).  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 Detection algorithm  (see  Sections  7.2
              and  7.3  of  RFC  4861).  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.

              Must be  either  zero  or  between  MaxRtrAdvInterval  and  9000
              seconds.

              Default: 3 * MaxRtrAdvInterval (Minimum 1 second).

       AdvDefaultPreference low|medium|high

              The  preference  associated  with  the default router, as either
              "low", "medium", or "high".

              Default: medium

       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    MinRtrAdvInterval    and
              MaxRtrAdvInterval.

              Default: off

       AdvHomeAgentInfo on|off

              When set, Home Agent Information  Option  (specified  by  Mobile
              IPv6)  is  included  in Router Advertisements.  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
              AdvHomeAgentInfo is not set.

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

              Default: AdvDefaultLifetime

       HomeAgentPreference integer

              The  preference  for  the  Home  Agent   sending   this   Router
              Advertisement.   Values  greater than 0 indicate more preferable
              Home Agent, values less 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 Information Option will not be
              sent.

              Default: 0

       AdvMobRtrSupportFlag on|off

              When set, the Home  Agent  signals  it  supports  Mobile  Router
              registrations  (specified by NEMO Basic).  AdvHomeAgentInfo must
              also be set when using this option.

              Default: off

       AdvIntervalOpt on|off

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

              The   advertisement   interval   is   based  on  the  configured
              MaxRtrAdvInterval parameter  except  where  this  is  less  than
              200ms.    In   this   case,   the   advertised   interval  is  (
              MaxRtrAdvInterval + 20ms ).

              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  advertisement  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 4862.

              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

       AdvValidLifetime seconds|infinity

              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 4862.

              Note  that  clients  will ignore AdvValidLifetime of an existing
              prefix if the lifetime is below two hours, as  required  in  RFC
              4862 Section 5.5.3 point e).

              Note: RFC4861’s suggested default value is significantly longer:
              30 days.

              Default: 86400 seconds (1 day)

       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  represents  infinity  (i.e.  a  value  of all one bits
              (0xffffffff)).  See RFC 4862.

              Note: RFC4861’s suggested default value is significantly longer:
              7 days.

              Default: 14400 seconds (4 hours)

       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 (including 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 reconfigured.

              This option enables  systems  with  dynamic  IPv4  addresses  to
              update their advertised 6to4 prefixes simply by restarting radvd
              or sending a SIGHUP signal 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  AdvValidLifetime  and  AdvPreferredLifetime
              options).

              For more information on 6to4, see RFC 3056.

              Default: 6to4 is not used

ROUTE SPECIFIC OPTIONS

       AdvRouteLifetime seconds|infinity

              The lifetime associated with the route in units of seconds.  The
              symbolic value infinity represents infinity (i.e. a value of all
              one bits (0xffffffff)).

              Default: 3 * MaxRtrAdvInterval

       AdvRoutePreference low|medium|high

              The preference associated with the  default  router,  as  either
              "low", "medium", or "high".

              Default: medium

RDNSS SPECIFIC OPTIONS

       AdvRDNSSPreference integer;

              The  preference of the DNS server, compared to other DNS servers
              advertised and used.  0 to 7 means less important than  manually
              configured nameservers in resolv.conf, while 12 to 15 means more
              important.

              NOTE: This feature was removed from the final RFC but can  still
              be used for experimental purposes.

              Default: 8

       AdvRDNSSOpen on|off;

              "Service Open" flag. When set, indicates that RDNSS continues to
              be available to hosts even if they moved to a different  subnet.

              NOTE:  This feature was removed from the final RFC but can still
              be used for experimental purposes.

              Default: off

       AdvRDNSSLifetime seconds|infinity;
              The maximum duration how long the RDNSS  entries  are  used  for
              name  resolution.  A  value  of 0 means the nameserver should no
              longer be used.  The maximum duration how long the RDNSS entries
              are  used for name resolution. A value of 0 means the nameserver
              should no longer be used.  The value, if not 0, must be at least
              MaxRtrAdvInterval.  To ensure stale RDNSS info gets removed in a
              timely   fashion,   this   should   not    be    greater    than
              2*MaxRtrAdvInterval.

              Default: 2*MaxRtrAdvInterval

EXAMPLES

       interface eth0
       {
               AdvSendAdvert on;
               prefix 2001:db8:0:1::/64
               {
                       AdvOnLink on;
                       AdvAutonomous on;
               };
       };

       It   says   that   router   advertisement   daemon   should   advertise
       (AdvSendAdvert on;) the prefix 2001:db8:0:1:: 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 2001:db8:0:1::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.  When advertising to on a dynamic interface
       (e.g., Bluetooth), skip the interface if it is not active yet.

       interface bnep0
       {
               IgnoreIfMissing on;
               AdvSendAdvert on;

               # Advertise at least every 30 seconds
               MaxRtrAdvInterval 30;

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

                       # Very short lifetimes for dynamic addresses
                       AdvValidLifetime 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.)

       In this specific case, the configuration scripts may send HUP signal to
       radvd  when  taking bnep0 up or down to notify about the status; in the
       current radvd releases, sending HUP is no  longer  mandatory  when  the
       link comes back up.

       interface eth0
       {
               AdvSendAdvert on;
               prefix 2001:db8:0:1::/64
               {
                       AdvOnLink on;
                       AdvAutonomous on;
               };
               clients
               {
                       fe80::21f:16ff:fe06:3aab;
                       fe80::21d:72ff:fe96:aaff;
               };
       };

       This    configuration    would    only    announce    the   prefix   to
       fe80::21f:16ff:fe06:3aab  and  fe80::21d:72ff:fe96:aaff.   Furthermore,
       all RA requests of other clients are denied.

       This  may  come  in  handy  if you want to roll out IPv6 only partially
       because some clients are broken or untested.

FILES

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

CREDIT

       The description of the different flags and variables is in large  parts
       taken from RFC 4861.

RFCS

       Narten,  T.,  Nordmark,  E.,  Simpson,  W.,  and  H. Soliman, "Neighbor
       Discovery for IP Version 6 (IPv6)", RFC 4861, September 2007.

       Thomson,  S.,  Narten,  T.,  T.   Jinmei,   "IPv6   Stateless   Address
       Autoconfiguration", RFC 4862, September 2007.

       Deering, S., and R. Hinden, "IP Version 6 Addressing Architecture", RFC
       4291, February 2006.

       Conta, A., Deering, S., and M. Gupta "Internet Control Message Protocol
       (ICMPv6)  for  the Internet Protocol Version 6 (IPv6)", RFC 4443, March
       2006.

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

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

       Draves, R., D. Thaler, "Default Router  Preferences  and  More-Specific
       Routes", RFC 4191, November 2005.

       Johnson, D., Perkins, C., and J. Arkko, "Mobility Support in IPv6", RFC
       3775, June 2004.

       Devarapalli, V., Wakikawa, R., Petrescu, A., and  P.  Thubert  "Network
       Mobility (NEMO) Basic Support Protocol", RFC 3963, January 2005.

       J.  Jeong,  L.  Beloeil, and S. Madanapalli, "IPv6 Router Advertisement
       Option for DNS Configuration", RFC 5006, September 2007.

SEE ALSO

       radvd(8), radvdump(8)

BUGS

       radvd does not support splitting up RAs to  multiple  packets  (RFC4861
       6.2.3  last  paragraph).   In  practise  this limits advertising to ~45
       prefixes on a link, but there is no reason to be able to so.