RAdv: Documentation for more specific routes

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Michal 'vorner' Vaner 2017-09-19 17:23:31 +02:00 committed by Ondrej Zajicek (work)
parent 7c0bab3a39
commit 18352188ed

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@ -3336,7 +3336,8 @@ time intervals or as an answer to a request) advertisement packets to connected
networks. These packets contain basic information about a local network (e.g. a
list of network prefixes), which allows network hosts to autoconfigure network
addresses and choose a default route. BIRD implements router behavior as defined
in <rfc id="4861"> and also the DNS extensions from <rfc id="6106">.
in <rfc id="4861">, router preferences and specific routes (<rfc id="4191">),
and DNS extensions (<rfc id="6106">).
<sect1>Configuration
<label id="radv-config">
@ -3373,7 +3374,7 @@ definitions, prefix definitions and DNS definitions:
definitions may also be interface-specific when used inside interface
options. By default, interface uses both global and interface-specific
options, but that can be changed by <cf/rdnss local/ option.
dsc-iface
<tag><label id="radv-dnssl">dnssl { <m/options/ }</tag>
DNSSL definitions allow to specify a list of advertised DNS search
domains together with their options. Like <cf/rdnss/ above, multiple
@ -3398,6 +3399,18 @@ dsc-iface
default router. <cf/preferred lifetime/ and <cf/valid lifetime/ could
also be configured as <cf/sensitive/ for a prefix, which would cause
autoconfigured IPs to be deprecated or even removed.
<tag><label id="radv-propagate-routes">propagate routes <m/switch/</tag>
This option controls propagation of more specific routes, as defined in
<rfc id="4191">. If enabled, all routes exported to the RAdv protocol,
with the exception of the trigger prefix, are added to advertisments as
additional options. The lifetime and preference of advertised routes can
be set individually by <cf/ra_lifetime/ and <cf/ra_preference/ route
attributes, or per interface by <cf/route lifetime/ and
<cf/route preference/ options. Default: disabled.
Note that the RFC discourages from sending more than 17 routes and
recommends the routes to be configured manually.
</descrip>
<p>Interface specific options:
@ -3444,21 +3457,45 @@ dsc-iface
hosts. Valid values are 0-255, 0 means unspecified. Default: 64
<tag><label id="radv-iface-default-lifetime">default lifetime <m/expr/ [sensitive <m/switch/]</tag>
This option specifies the time (in seconds) how long (after the receipt
This option specifies the time (in seconds) how long (since the receipt
of RA) hosts may use the router as a default router. 0 means do not use
as a default router. For <cf/sensitive/ option, see <ref id="radv-trigger" name="trigger">.
Default: 3 * <cf/max ra interval/, <cf/sensitive/ yes.
<tag><label id="radv-iface-linger-time">linger time <m/expr/</tag>
When a prefix disappears, it is advertised for some time with 0
lifetime, to inform clients the prefix is no longer usable. This option
sets the time for how long it is advertised (in seconds). Maximum is
3600, 0 means disabled. Default: 300.
<tag><label id="radv-iface-default-preference-low">default preference low|medium|high</tag>
<tag><label id="radv-iface-default-preference">default preference low|medium|high</tag>
This option specifies the Default Router Preference value to advertise
to hosts. Default: medium.
<tag><label id="radv-iface-route-lifetime">route lifetime <m/expr/ [sensitive <m/switch/]</tag>
This option specifies the default value of advertised lifetime for
specific routes; i.e., the time (in seconds) for how long (since the
receipt of RA) hosts should consider these routes valid. A special value
0xffffffff represents infinity. The lifetime can be overriden on a per
route basis by the <ref id="rta-ra-lifetime" name="ra_lifetime"> route
attribute. Default: 3 * <cf/max ra interval/, <cf/sensitive/ no.
For the <cf/sensitive/ option, see <ref id="radv-trigger" name="trigger">.
If <cf/sensitive/ is enabled, even the routes with the <cf/ra_lifetime/
attribute become sensitive to the trigger.
<tag><label id="radv-iface-route-preference">route preference low|medium|high</tag>
This option specifies the default value of advertised route preference
for specific routes. The value can be overriden on a per route basis by
the <ref id="rta-ra-preference" name="ra_preference"> route attribute.
Default: medium.
<tag><label id="radv-prefix-linger-time">prefix linger time <m/expr/</tag>
When a prefix or a route disappears, it is advertised for some time with
zero lifetime, to inform clients it is no longer valid. This option
specifies the time (in seconds) for how long prefixes are advertised
that way. Default: 3 * <cf/max ra interval/.
<tag><label id="radv-route-linger-time">route linger time <m/expr/</tag>
When a prefix or a route disappears, it is advertised for some time with
zero lifetime, to inform clients it is no longer valid. This option
specifies the time (in seconds) for how long routes are advertised
that way. Default: 3 * <cf/max ra interval/.
<tag><label id="radv-iface-rdnss-local">rdnss local <m/switch/</tag>
Use only local (interface-specific) RDNSS definitions for this
interface. Otherwise, both global and local definitions are used. Could
@ -3505,7 +3542,6 @@ dsc-iface
<cf/sensitive/ no.
</descrip>
<p>RDNSS specific options:
<descrip>
@ -3538,12 +3574,48 @@ dsc-iface
RDNSS <cf/lifetime/ option above. Default: 3 * <cf/max ra interval/.
</descrip>
<sect1>Attributes
<label id="radv-attr">
<p>RAdv defines two route attributes:
<descrip>
<tag><label id="rta-ra-preference">enum ra_preference/</tag>
The preference of the route. The value can be <it/RA_PREF_LOW/,
<it/RA_PREF_MEDIUM/ or <it/RA_PREF_HIGH/. If the attribute is not set,
the <ref id="radv-iface-route-preference" name="route preference">
option is used.
<tag><label id="rta-ra-lifetime">int ra_lifetime/</tag>
The advertised lifetime of the route, in seconds. The special value of
0xffffffff represents infinity. If the attribute is not set, the
<ref id="radv-iface-route-lifetime" name="route lifetime">
option is used.
</descrip>
<sect1>Example
<label id="radv-exam">
<p><code>
table radv_routes; # Manually configured routes go here
protocol static {
table radv_routes;
route 2001:0DB8:4000::/48 unreachable;
route 2001:0DB8:4010::/48 unreachable;
route 2001:0DB8:4020::/48 unreachable {
ra_preference = RA_PREF_HIGH;
ra_lifetime = 3600;
};
}
protocol radv {
propagate routes yes; # Propagate the routes from the radv_routes table
table radv_routes;
export all;
interface "eth2" {
max ra interval 5; # Fast failover with more routers
managed yes; # Using DHCPv6 on eth2