Provided by: radvd_1.8-1_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
            list of DNSSL 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 all 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
       };

       DNSSL (DNS Search List) definitions are of the form:

       DNSSL suffix [suffix] [suffix] [...] {
            list of dnssl 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: on

       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)

       DeprecatePrefix on|off

              Upon  shutdown,  this  option  will cause radvd to deprecate the
              prefix by announcing it in the radvd shutdown  RA  with  a  zero
              preferred  lifetime and a valid lifetime slightly greater than 2
              hours. This  will  encourage  end-nodes  using  this  prefix  to
              deprecate  any  associated addresses immediately. Note that this
              option should only be used when only one  router  is  announcing
              the  prefix  onto  the  link, otherwise end-nodes will deprecate
              associated addresses despite the prefix still  being  valid  for
              preferred use.

              See  RFC4862, section 5.5.3., "Router Advertisement Processing",
              part (e).

              Default: off

       DecrementLifetimes on|off

              This  option  causes  radvd  to  decrement  the  values  of  the
              preferred  and  valid  lifetimes  for  the prefix over time. The
              lifetimes are decremented by the number  of  seconds  since  the
              last  RA.  If radvd receives a SIGUSR1 signal, it will reset the
              values of the preferred and valid lifetimes back to the  initial
              values  used by radvd when it started. If radvd never receives a
              SIGUSR1 signal, it will  continue  to  decrement  the  lifetimes
              until the preferred lifetime reaches zero. After a final RA with
              a zero value preferred lifetime, radvd will  cease  to  announce
              the  prefix. If a SIGUSR1 signal then causes the lifetimes to be
              reset, the prefix will then re-appear in the RAs.

              This option is intended to be used in conjunction with a  DHCPv6
              client  that  is  using  the  Identity  Association  for  Prefix
              Delegation (IA_PD) option to acquire a prefix from a  Delegating
              Router  for  use  by  a Requesting Router. In this scenario, the
              prefix(es) from within the delegated prefix that  are  announced
              by  radvd would age in parallel with and at the same rate as the
              delegated prefix, and expire at approximately the same time,  if
              the delegated prefix's life isn't extended.

              See RFC3633, "IPv6 Prefix Options for Dynamic Host Configuration
              Protocol (DHCP) version 6".

              Default: off

       Base6Interface name

              If this options is specified, this prefix will be combined  with
              the  IPv6  address  of  the  interface  specified  by name.  The
              resulting prefix length will be 64.

       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

       RemoveRoute on|off

              Upon  shutdown, announce this route with a zero second lifetime.
              This should cause the route to be immediately removed  from  the
              receiving end-nodes' route table.

              Default: on

RDNSS SPECIFIC OPTIONS

       AdvRDNSSLifetime seconds|infinity
              The  maximum  duration  how  long the RDNSS entries are used for
              name resolution. A value of  0  means  the  nameserver  must  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

       FlushRDNSS on|off

              Upon shutdown, announce the RDNSS entries  with  a  zero  second
              lifetime.   This   should   cause  the  RDNSS  addresses  to  be
              immediately removed from the end-nodes' list  of  Recursive  DNS
              Servers.

              Default: on

DNSSL SPECIFIC OPTIONS

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

              Default: 2*MaxRtrAdvInterval

       FlushDNSSL on|off

              Upon shutdown, announce the DNSSL entries  with  a  zero  second
              lifetime.  This should cause the DNSSL entries to be immediately
              removed from the end-nodes' DNS search list.

              Default: on

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, S.  Park,  L.  Beloeil,  and  S.  Madanapalli,  "IPv6  Router
       Advertisement Options for DNS Configuration", RFC 6106, November 2010.

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.