ISC DHCP eui-64 based allocation
Quoting dhcpd.conf.5 about the optionAL EUI-64 feature:
use-eui-64 flag;
The use-eui-64 flag, if enabled, instructs the server to con-
struct an address using the client's EUI-64 DUID (Type 3, HW
Type EUI-64), rather than creating an address using the dynamic
algorithm. This means that a given DUID will always generate
the same address for a given pool and further that the address
is guaranteed to be unique to that DUID. The IPv6 address will
be calculated from the EUI-64 link layer address, conforming to
RFC 2373, unless there is a host declaration for the client-id.
The range6 statement for EUI-64 must define full /64 bit ranges.
Invalid ranges will be flagged during configuration parsing as
errors. See the following example:
subnet6 fc00:e4::/64 {
use-eui-64 true;
range6 fc00:e4::/64;
}
The statement may be specified down to the pool level, allowing
a mixture of dynamic and EUI-64 based pools.
During lease file parsing, any leases which map to an EUI-64
pool, that have a non-EUI-64 DUID or for which the lease address
is not the EUI-64 address for that DUID in that pool, will be
discarded.
If a host declaration exists for the DUID, the server grants the
address (fixed-prefix6, fixed-address6) according to the host
declaration, regardless of the DUID type of the client (even for
EUI-64 DUIDs).
If a client request's an EUI-64 lease for a given network, and
the resultant address conflicts with a fixed address reserva-
tion, the server will send the client a "no addresses available"
response.
Any client with a non-conforming DUID (not type 3 or not hw type
EUI-64) that is not linked to a host declaration, which requests
an address from an EUI-64 enabled pool will be ignored and the
event will be logged.
Any client with a non-conforming DUID (not type 3 or not hw type
EUI-64) that is not linked to a host declaration, which requests
an address from an EUI-64 enabled pool will be ignored and the
event will be logged.
Pools that are configured for EUI-64 will be skipped for dynamic
allocation. If there are no pools in the shared network from
which to allocate, the client will get back a no addresses
available status.
On an EUI-64 enabled pool, any client with a DUID 3, HW Type
EUI-64, requesting a solicit/renew and including IA_NA that do
not match the EUI-64 policy, they will be treated as though they
are "outside" the subnet for a given client message:
Solicit - Server will advertise with EUI-64 ia suboption,
but with rapid
commit off
Request - Server will send "an address not on link status",
and no ia
suboption Renew/Rebind - Server will send the requested
address ia
suboption with lifetimes of 0, plus an EUI-64 ia
Whether or not EUI-64 based leases are written out to the lease
database may be controlled by persist-eui-64-leases statement.
Added to ISC DHCP as an optional feature on customer request. Can be ported to Kea.