Greenfield IPv4 + IPv6 broadband deployment

Frank Bulk frnkblk at
Sun Feb 27 03:38:05 CET 2011

Why would you have a separate /64 stubnet (between CE and PE)?  Then each
customer would use a /64 + (48 or 56 or 64).  

I'm currently using a /56 in the 1:N model so that each CE's WAN interface
is in the same /56.


-----Original Message-----
From: at
[ at] On Behalf Of
Dan White
Sent: Saturday, February 26, 2011 5:31 PM
To: Adam Armstrong
Cc: IPv6 operators forum
Subject: Re: Greenfield IPv4 + IPv6 broadband deployment

On 26/02/11 18:07 +0000, Adam Armstrong wrote:
>Hi All,
>I'm currently in the planning stages of a large scale broadband 
>deployment, with the hopes of doing sane dual-stacked v4/v6 to every 
>subscriber from day one.
>I know the CPE issue has been talked about to death, and I'm pretty 
>unhappy with the situation there at the moment, but for the time 
>being I'm assuming CPE are not an issue.
>All transport is ethernet, with subs being dragged back to a small 
>number of central gateways. I'm looking at a mix of DHCP and 
>DHCPv6-PD to distribute addresses. PPP isn't an option.

Some of this has already been mentioned by Frank and Martin and others.

I'd recommend investing in a good router (or routers) which support
subscriber management, and try to design your network so that your
customers terminate to it via Q-in-Q VLANs (or ATM or PPPoX where
appropriate), and handle your layer-3 enforcement on that router rather
than at the edge.

Assign static v4 addresses, or enforce DHCPv4 leases on the router. Use
proxy ARP to allow customers to talk to each other if you want (a good
subscriber management router is going to have all that).

For IPv6, assign or identify customers via subnet rather than individual v6
addresses, where you can get away with it. Assign a /64 per layer-2
broadcast domain (one broadcast domain per customer if you can), and
provide a unique RA per customer. Set up a pool of DHCPv6-PD subnets (/56
or /48 per customer) that customer routers can request from, or configure a
static DHCPv6-PD pool per customer if that makes sense. Configure the
'Other configuration' flag in your RAs so customer routers retrieve DNS
servers dynamically.

Consider how you're going to handle the inevitable abuse complaints your
going to receive (SPAM and Copyright violations), and how you're going
to identify which customer triggered the complaint.

Dan White

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