IPv6 RA vs DHCPv6 - The chosen one?

Wed Dec 21 21:31:35 UTC 2011

Hi,

Op 21 dec 2011, om 20:16 heeft Tomas Podermanski het volgende geschreven:

> Hi,
> 
> from my perspective the short answer for this never-ending story is:

To be fair, SLAAC was designed as a light weight method to configure addressing on the hosts.

Hosts. We don't have hosts on the internet anymore, we stopped using dialup ages ago (or so it seems). We now address routers, and those have very different requirements, like needing routing and firewalling and some way to get subnets routed to them, that is where dhcp6 prefix delegation comes in. SLAAC serves no purpose for routers bar making the configure process awkward and error prone.

That wasn't what we needed.

I recently had a conversation with a promoter of the SLAAC method.

"A 64KB ram device can configure a address and work as a autonomous sensor".

I raised the concern that the device might need to connect to a host, since you couldn't find it in a /64 of address space. He honestly suggested that you could just configure to have it connect to a static address.

Really, and nobody renumbers networks, at all? That's false.

And that is still a host, not a router.

And since then we've come a lot farther then 64KB sensor devices. Considering we can buy (wireless) routers at the local mall that have more ram and processing power then we used to have in a computer in the 90s now in a tablet, phone or other embedded device.

Having built DHCP6 support in a open source firewall I agree that the (+IPv6) configuration of routers has become overly complicated and error prone, even more so due to possible renumbering. RA will have one thought, and the DHCP6 client another, not even going into multiple (possible differing) feeds of both IPv4 and IPv6 DNS servers.

It was intended for hosts, not really minding that, but please, can we stop using it for routers?

Regards,

Seth