[PATCH pve-docs v5 9/9] sdn: add IPv6 RA / SLAAC section

[Hannes Laimer <h.laimer@proxmox.com>]

Signed-off-by: Hannes Laimer <h.laimer@proxmox.com>
---
 pvesdn.adoc | 71 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 71 insertions(+)

diff --git a/pvesdn.adoc b/pvesdn.adoc
index 3fd3533ad07f..dc634fe43074 100644
--- a/pvesdn.adoc
+++ b/pvesdn.adoc
@@ -409,6 +409,10 @@ xref:pvesdn_firewall_integration[VNET Firewall] to further isolate traffic in
 the VNET across nodes. For example, DROP by default and only allow traffic from
 the IP subnet to the gateway and vice versa.
 
+A VNet in an EVPN zone can send
+xref:pvesdn_config_ipv6_ra[IPv6 Router Advertisements], so guests configure
+their IPv6 addresses themselves.
+
 [[pvesdn_config_subnet]]
 Subnets
 -------
@@ -442,6 +446,73 @@ SNAT:: Enable Source NAT which allows VMs from inside a
 DNS Zone Prefix:: Add a prefix to the domain registration, like
   <hostname>.prefix.<domain>  Optional.
 
+An IPv6 subnet in an EVPN zone has additional per-prefix options for
+xref:pvesdn_config_ipv6_ra[IPv6 Router Advertisements].
+
+
+[[pvesdn_config_ipv6_ra]]
+IPv6 Router Advertisements (SLAAC)
+----------------------------------
+
+A VNet in an xref:pvesdn_zone_plugin_evpn[EVPN zone] can send IPv6 Router
+Advertisements (RAs) on its bridge, from every node of the zone. Guests on the
+VNet then configure their IPv6 addresses through Stateless Address
+Autoconfiguration (SLAAC) and learn the gateway from the RA. The RA can also
+carry DNS servers, a link MTU, and the flags that point guests to DHCPv6.
+
+RAs are enabled per VNet on the 'IPv6 Router Advertisement' tab of the VNet,
+under `Datacenter -> SDN -> VNets`. The VNet advertises each of its IPv6
+subnets as a prefix, with the settings of that prefix on the 'IPv6 Prefix
+Options' tab of the subnet. Both tabs are only available in EVPN zones.
+
+A VNet without an IPv6 subnet sends no RAs. With the defaults, a /64 subnet
+lets guests autoconfigure without further settings.
+
+Options on the VNet:
+
+Send Router Advertisements:: Enable RAs on this VNet. The other options on the
+  tab only take effect while this is enabled. Optional.
+
+DHCP Managed (M):: Set the managed-address (M) flag, which tells guests to also
+  request an address from a DHCPv6 server. Optional.
+
+DHCP Other (O):: Set the other-configuration (O) flag, which tells guests to
+  get other settings, such as DNS servers, from a DHCPv6 server. Optional.
+
+RDNSS:: Recursive DNS server (RDNSS) addresses to advertise, so guests learn
+  their resolvers from the RA. Optional.
+
+Router Lifetime (s):: Seconds for which guests keep the gateway as their
+  default router, 0 to 9000. With 0, guests do not use the gateway as a default
+  router, for example when the RA only distributes a prefix or DNS servers. A
+  value above 0 must be at least the RA interval. Optional, defaults to three
+  times the RA interval.
+
+RA Interval (s):: Maximum number of seconds between two unsolicited RAs,
+  4 to 1800. Optional, defaults to 600.
+
+Advertised MTU:: Link MTU to advertise to guests, 1280 to 65535. Optional,
+  without it the RA carries no MTU.
+
+Options on each IPv6 subnet:
+
+SLAAC (A):: Set the autonomous (A) flag, which lets guests derive an address
+  from this prefix. SLAAC needs a /64 prefix, so the flag is enabled by default
+  on /64 subnets and cannot be set on others. Such subnets are still
+  advertised, without the flag.
+
+On-link (L):: Set the on-link (L) flag, which tells guests that addresses in
+  this prefix are reachable directly on the link rather than through the
+  gateway. Optional, enabled by default.
+
+Valid Lifetime (s):: Seconds the prefix, and addresses derived from it, stay
+  valid. Optional, defaults to 2592000 (30 days).
+
+Preferred Lifetime (s):: Seconds an address derived from this prefix stays
+  preferred for new connections. Must not exceed the valid lifetime. If only a
+  shorter valid lifetime is set, the preferred lifetime is lowered to match
+  it. Optional, defaults to 604800 (7 days).
+
 
 [[pvesdn_config_controllers]]
 Controllers
-- 
2.47.3