Pierre Pfister <mailto:[email protected]>
14 March 2015 09:10
Hello Ray,
Thanks for the review.
Their actually is something about that already. Sub-delegation is one
of the purposes of the so called « Private Links »
Private Link: A Private Link is an abstract concept defined for the
sake of this document. It allows nodes to make assignments for
their private use or delegation. For instance, every DHCPv6-PD
[RFC3633 <https://tools.ietf.org/html/rfc3633>] client MAY be
considered as a different Private Link.
Another node, by some mean such as DHCPv6-PD, asks for prefixes. In
order to provide a prefix, the algorithm may be executed on a Private
Link representing that client node. It is true that the proxy needs to
be careful when it provides prefixes this way. Which is why the
« Apply Timer » exists.
Applied (Assigned Prefix): When an Assigned Prefix is applied, it
MAY be used (e.g., for host configuration, routing protocol
configuration, prefix delegation). When not applied, it MUST NOT
be used for any other purposes than the prefix assignment
algorithm. […]
In order to help moving forward with specifications, the PA draft was
purged from any purely Homenet specific considerations (Prefix Length
considerations, Prefix Lifetimes, ULA generation, …). These
considerations now belong to the hncp document
(draft-ietf-homenet-hncp-04). Particularly, Recursive Prefix
Delegation is described in Section 6.2.6 of the HNCP document.
Thanks,
- Pierre
------------------------------------------------------------------------
OK Got it. Thanks.
Another question. I've been testing with smaller prefixes than that
required to configure the Homenet.
Is behavior defined for that situation?
i.e. I am delegating a /60 but I have 9 interfaces (with 4 common) = 6
prefixes to assign in Homenet.
Theoretically that should fit. And it does
Delegating router gives out a lease for 2001:6d8 :67d2 :1f0::/60
So Homenet 1 has
2001:6d8:67d2:1f9:16cc:20ff:fe8a:15c4/64(common with Homenet 2)
2001:6d8:67d2:1ff:16cc:20ff:fe8a:15c4/64
2001:6d8:1f15:62e:16cc:20ff:fe8a:15c4/64 (WAN)
Homenet 2 has
2001:6d8:67d2:1f9:16cc:20ff:fe8a:15d6/64 (common with Homenet 1)
2001:6d8:67d2:1f5:16cc:20ff:fe8a:15d6/64
2001:6d8:67d2:1f7:16cc:20ff:fe8a:15d6/64 (common with Homenet 3)
Homenet 3 has
2001:6d8 :67d2 :1f7:16cc:20ff:fe8a:154c/64 (common with Homenet 2)
2001:6d8 :67d2 :1f3:16cc:20ff:fe8a:154c/64
2001:6d8 :67d2 :1f2:16cc:20ff:fe8a:154c/64
Now if I reduce the lease to a /62 I get problems (as expected)
lease granted is 2001:6d8 :67d2 :130::/62
2001:6d8 :67d2 :131:b834::89fe/80(common with Homenet 2)
2001:6d8 :67d2 :131:2eb6::9bb2/80
2001:6d8:1f15:62e:16cc:20ff:fe8a:15c4/64 (WAN)
Homenet 2 has
2001:6d8 :67d2 :131:b834::e8a9/80 (common with Homenet 1)
2001:6d8 :67d2 :131:2e46::a68a/80
2001:6d8 :67d2 :130:16cc:20ff:fe8a:15d6/64 (common with Homenet 3)
Homenet 3 (powered on first) has
2001:6d8 :67d2 :132:16cc:20ff:fe8a:154c/64
2001:6d8 :67d2 :133:16cc:20ff:fe8a:154c/64
2001:6d8 :67d2 :130:16cc:20ff:fe8a:154c/64 (common with Homenet 2)
So this looks like a pathological case (as expected).
Is it defined what should happen in this case?
Should a prefix be split, or simply as many /64's as possible be assigned?
If it were theoretically possible to discover that inter-router links
were actually point to point links, should these be assigned /127's or
the /80's instead?
That would preserve more /64's for end user systems. One mechanism could
be to check the ND cache for other link local entries, other than other
Homenet speaking routers?
I've also tried to add additional /62 prefixes to the DHCP PD server
(fake ISP router) DHCPD config, but the Homenet either doesn't request
these, or the ISC code isn't assigning them.
The homenet is thus only using a single lease, rather than concatenating
multiple small leases.
That to me would either simulate the situation where multiple small
leases were available from one ISP for utilization to number links from
multiple prefixes, or a make before break renumbering event was upcoming.
Either way I'd expect the Homenet to somehow grab these additional
leases if it had run out in the original PD assignment space, or to
prepare for renumbering by assigning dual prefixes per link.
Is there anything to define in your draft?
e.g. Multiple address pools obtained from a single source SHOULD NOT be
concatenated, but treated as a potential make before break renumbering
event.
--
Regards,
RayH
_______________________________________________
homenet mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/homenet
