Android (lack of) support for DHCPv6

Mikael Abrahamsson swmike at swm.pp.se
Wed Jun 10 13:53:35 UTC 2015


On Wed, 10 Jun 2015, Baldur Norddahl wrote:

> I need the GUA to have a stable and predictable next hop for my static
> route of the /48 prefix delegation.
>
> What standard exactly requires my router to be able to snoop a DHCP-PD to
> create routes dynamically? That was left out and one solution is the one we
> use.
>
> Note that the /48 static routes are configured on the routers well in
> advantage of the customer even signing up for the service. It is just there
> waiting for a customer to be assigned the corresponding /128.

Well, then you're not doing what most people do when they do DHCPv6-PD, 
you're using something else. This is the first time I have heard of anyone 
doing what you describe.

Normally it's done by the router acting on DHCPv6 packets and installing a 
route if need be.

http://www.cisco.com/c/en/us/support/docs/ip/ip-version-6-ipv6/113141-DHCPv6-00.html

As soon as the PD is handed out, a corresponding route will be installed 
for that PD to the address (potentially LL address) that requested that 
PD.

> getting DoS attacks on NDP, extra CPU use etc on my network. Why would I
> want that, when I can deliver perfect service to the customer with a fixed
> cache of 2 entries?

If you did PD the way it's normally done, you would need 1 entry, not 2.

I do agree that you do not want your equipment sitting in the same 
broadcast domain as all the customers devices, but do use PD. I'm just 
baffled by the way you have implemented "PD".

-- 
Mikael Abrahamsson    email: swmike at swm.pp.se



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