doc/user/ipv6.rst

   1 .. _ipv6-support:
   2
   3 ************
   4 IPv6 Support
   5 ************
   6
   7 FRR fully supports IPv6 routing.  As described so far, FRR supports RIPng,
   8 OSPFv3, and BGP-4+.  You can give IPv6 addresses to an interface and configure
   9 static IPv6 routing information.  FRR IPv6 also provides automatic address
  10 configuration via a feature called ``address auto configuration``.  To do it,
  11 the router must send router advertisement messages to the all nodes that exist
  12 on the network.
  13
  14 Previous versions of FRR could be built without IPv6 support.  This is
  15 no longer possible.
  16
  17 Router Advertisement
  18 ====================
  19
  20 .. clicmd:: show ipv6 nd ra-interfaces [vrf <VRFNAME|all>]
  21
  22    Show configured route advertisement interfaces. VRF subcommand only
  23    applicable for netns-based vrfs.
  24
  25 .. clicmd:: ipv6 nd suppress-ra
  26
  27    Don't send router advertisement messages. The ``no`` form of this command
  28    enables sending RA messages.
  29
  30 .. clicmd:: ipv6 nd prefix ipv6prefix [valid-lifetime] [preferred-lifetime] [off-link] [no-autoconfig] [router-address]
  31
  32    Configuring the IPv6 prefix to include in router advertisements. Several prefix
  33    specific optional parameters and flags may follow:
  34
  35    - ``valid-lifetime``: the length of time in seconds during what the prefix is
  36      valid for the purpose of on-link determination. Value ``infinite`` represents
  37      infinity (i.e. a value of all one bits (``0xffffffff``)).
  38      Range: ``(0-4294967295)``  Default: ``2592000``
  39
  40    - ``preferred-lifetime``: the length of time in seconds during what addresses
  41      generated from the prefix remain preferred. Value ``infinite`` represents
  42      infinity.
  43      Range: ``(0-4294967295)``  Default: ``604800``
  44
  45    - ``off-link``: indicates that advertisement makes no statement about on-link or
  46      off-link properties of the prefix.
  47      Default: not set, i.e. this prefix can be used for on-link determination.
  48
  49    - ``no-autoconfig``: indicates to hosts on the local link that the specified prefix
  50      cannot be used for IPv6 autoconfiguration.
  51
  52      Default: not set, i.e. prefix can be used for autoconfiguration.
  53
  54    - ``router-address``: indicates to hosts on the local link that the specified
  55      prefix contains a complete IP address by setting R flag.
  56
  57      Default: not set, i.e. hosts do not assume a complete IP address is placed.
  58
  59 .. clicmd:: ipv6 nd ra-interval [(1-1800)]
  60
  61    The maximum time allowed between sending unsolicited multicast router
  62    advertisements from the interface, in seconds.
  63    Default: ``600``
  64
  65 .. clicmd:: ipv6 nd ra-interval [msec (70-1800000)]
  66
  67    The maximum time allowed between sending unsolicited multicast router
  68    advertisements from the interface, in milliseconds.
  69    Default: ``600000``
  70
  71 .. clicmd:: ipv6 nd ra-fast-retrans
  72
  73    RFC4861 states that consecutive RA packets should be sent no more
  74    frequently than three seconds apart. FRR by default allows faster
  75    transmissions of RA packets in order to speed convergence and
  76    neighbor establishment, particularly for unnumbered peering.  By
  77    turning off ipv6 nd ra-fast-retrans, the implementation is
  78    compliant with the RFC at the cost of slower convergence
  79    and neighbor establishment.
  80    Default: enabled
  81
  82 .. clicmd:: ipv6 nd ra-retrans-interval [(0-4294967295)]
  83
  84    The value to be placed in the retrans timer field of router advertisements
  85    sent from the interface, in msec. Indicates the interval between router
  86    advertisement retransmissions. Setting the value to zero indicates that
  87    the value is unspecified by this router. Must be between zero or 4294967295
  88    msec.
  89    Default: ``0``
  90
  91 .. clicmd:: ipv6 nd ra-hop-limit [(0-255)]
  92
  93    The value to be placed in the hop count field of router advertisements sent
  94    from the interface, in hops. Indicates the maximum diameter of the network.
  95    Setting the value to zero indicates that the value is unspecified by this
  96    router.  Must be between zero or 255 hops.
  97    Default: ``64``
  98
  99 .. clicmd:: ipv6 nd ra-lifetime [(0-9000)]
 100
 101    The value to be placed in the Router Lifetime field of router advertisements
 102    sent from the interface, in seconds. Indicates the usefulness of the router
 103    as a default router on this interface. Setting the value to zero indicates
 104    that the router should not be considered a default router on this interface.
 105    Must be either zero or between value specified with ``ipv6 nd ra-interval``
 106    (or default) and 9000 seconds.
 107    Default: ``1800``
 108
 109 .. clicmd:: ipv6 nd reachable-time [(1-3600000)]
 110
 111    The value to be placed in the Reachable Time field in the Router
 112    Advertisement messages sent by the router, in milliseconds. The configured
 113    time enables the router to detect unavailable neighbors. The value zero
 114    means unspecified (by this router).
 115    Default: ``0``
 116
 117 .. clicmd:: ipv6 nd managed-config-flag
 118
 119    Set/unset flag in IPv6 router advertisements which indicates to hosts that
 120    they should use managed (stateful) protocol for addresses autoconfiguration
 121    in addition to any addresses autoconfigured using stateless address
 122    autoconfiguration.
 123    Default: not set
 124
 125 .. clicmd:: ipv6 nd other-config-flag
 126
 127    Set/unset flag in IPv6 router advertisements which indicates to hosts that
 128    they should use administered (stateful) protocol to obtain autoconfiguration
 129    information other than addresses.
 130    Default: not set
 131
 132 .. clicmd:: ipv6 nd home-agent-config-flag
 133
 134    Set/unset flag in IPv6 router advertisements which indicates to hosts that
 135    the router acts as a Home Agent and includes a Home Agent Option.
 136    Default: not set
 137
 138
 139 .. clicmd:: ipv6 nd home-agent-preference [(0-65535)]
 140
 141    The value to be placed in Home Agent Option, when Home Agent config flag is
 142    set, which indicates to hosts Home Agent preference. The default value of 0
 143    stands for the lowest preference possible.
 144    Default: ``0``
 145
 146 .. clicmd:: ipv6 nd home-agent-lifetime [(0-65520)]
 147
 148    The value to be placed in Home Agent Option, when Home Agent config flag is set,
 149    which indicates to hosts Home Agent Lifetime. The default value of 0 means to
 150    place the current Router Lifetime value.
 151
 152    Default: ``0``
 153
 154 .. clicmd:: ipv6 nd adv-interval-option
 155
 156    Include an Advertisement Interval option which indicates to hosts the maximum time,
 157    in milliseconds, between successive unsolicited Router Advertisements.
 158    Default: not set
 159
 160 .. clicmd:: ipv6 nd router-preference [(high|medium|low)]
 161
 162    Set default router preference in IPv6 router advertisements per RFC4191.
 163    Default: medium
 164
 165 .. clicmd:: ipv6 nd mtu [(1-65535)]
 166
 167    Include an MTU (type 5) option in each RA packet to assist the attached
 168    hosts in proper interface configuration. The announced value is not verified
 169    to be consistent with router interface MTU.
 170
 171    Default: don't advertise any MTU option.
 172
 173 .. clicmd:: ipv6 nd rdnss ipv6address [lifetime]
 174
 175    Recursive DNS server address to advertise using the RDNSS (type 25) option
 176    described in RFC8106. Can be specified more than once to advertise multiple
 177    addresses. Note that hosts may choose to limit the number of RDNSS addresses
 178    to track.
 179
 180    Optional parameter:
 181
 182    - ``lifetime``: the maximum time in seconds over which the specified address
 183      may be used for domain name resolution. Value ``infinite`` represents
 184      infinity (i.e. a value of all one bits (``0xffffffff``)). A value of 0
 185      indicates that the address must no longer be used.
 186      Range: ``(0-4294967295)``  Default: ``3 * ra-interval``
 187
 188    Default: do not emit RDNSS option
 189
 190 .. clicmd:: ipv6 nd dnssl domain-name-suffix [lifetime]
 191
 192    Advertise DNS search list using the DNSSL (type 31) option described in
 193    RFC8106. Specify more than once to advertise multiple domain name suffixes.
 194    Host implementations may limit the number of honored search list entries.
 195
 196    Optional parameter:
 197
 198    - ``lifetime``: the maximum time in seconds over which the specified domain
 199      suffix may be used in the course of  name resolution. Value ``infinite``
 200      represents infinity (i.e. a value of all one bits (``0xffffffff``)). A
 201      value of 0 indicates that the name suffix must no longer be used.
 202      Range: ``(0-4294967295)``  Default: ``3 * ra-interval``
 203
 204    Default: do not emit DNSSL option
 205
 206 Router Advertisement Configuration Example
 207 ==========================================
 208 A small example:
 209
 210 .. code-block:: frr
 211
 212    interface eth0
 213     no ipv6 nd suppress-ra
 214     ipv6 nd prefix 2001:0DB8:5009::/64
 215
 216
 217 .. seealso::
 218
 219    - :rfc:`2462` (IPv6 Stateless Address Autoconfiguration)
 220    - :rfc:`4861` (Neighbor Discovery for IP Version 6 (IPv6))
 221    - :rfc:`6275` (Mobility Support in IPv6)
 222    - :rfc:`4191` (Default Router Preferences and More-Specific Routes)
 223    - :rfc:`8106` (IPv6 Router Advertisement Options for DNS Configuration)