Greenfield IPv4 + IPv6 broadband deployment

Mikael Abrahamsson swmike at
Sun Feb 27 06:36:59 CET 2011

On Sun, 27 Feb 2011, Martin Millnert wrote:

> On a relatively high-end 48p L3 access switch, I'm not sure I agree that 
> ~16k ND entries are an insufficient amount for many, many years to come. 
> I'd be willing to make a bet with you that the device in question will 
> have been replaced long before the issue ever appeared. (I keep 
> customers habits of hooking up routers well in mind.)

16k might be enough, I've seen chassis switches which support 1-4k for a 
whole blade or even in a whole chassis.

> You are certainly right that one should investigate the limits of the
> equipment before deployment though, and I suspect that ND flood
> protection etc is mandated as well on customer interfaces.

One need to consider the CPU usage of all this ND traffic as well. I've 
seen CPU-related ARP issues on some generally high-end platforms (routers) 
at 10k ARP entries.

> All things considered is this another reason why it is very beneficial 
> to go the route of connecting customers directly on L3 edge devices IMO.

Absolutely. Security and fault-isolation is much much easier.

Mikael Abrahamsson    email: swmike at

More information about the ipv6-ops mailing list