v6 subnet size for DSL & leased line customers

Kevin Loch kloch at kl.net
Tue Dec 25 05:43:45 UTC 2007

Iljitsch van Beijnum wrote:
> On 24 dec 2007, at 20:00, Kevin Loch wrote:
>>> RA/Autoconf won't work at all for some folks with deployed server
>>> infra,
> That's just IPv4 uptightness. As long as you don't change your MAC 
> address you'll get the same IPv6 address every time, this works fine for 
> servers unless you need a memorable address. BTW, I don't know anyone 
> who uses DHCP for their servers.
>> Hopefully vrrpv6 will work with RA turned completely off.
> With router advertisements present you don't need VRRP because you have 
> dead neighbor detection.

And that helps the hosts on the same l2 segment that need different
gateways how?  Or hosts with access to multiple l2 segments with
different gateways?

RA is a shotgun.  All hosts on a segment get the same gateway.  I have 
no idea what a host on multiple segments with different gateways would 
do.  Hosting environments can get complex thanks to customer
requirements and baggage from previous migrations. Load balancer and VPN
configurations are common culprits but there are also cases where
servers need different gateways for routing policy reasons. All of this
is easily accommodated with static gateways and the redundancy provided
by vrrpv4.  Please don't take that away from us.  Migration to v6 will
be difficult enough without subtracting functionality from our existing

Other than that I look forward to seeing what wonderful things we can
do with RA to simplify things in cases where shotgun == ok.

- Kevin

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