On Thu, Oct 1, 2015 at 10:58 PM, Rob McEwen <rob@invaluement.com> wrote:
On 10/1/2015 11:44 PM, Mark Andrews wrote:
IPv6 really isn't much different to IPv4. You use sites /48's rather than addresses /32's (which are effectively sites). ISP's still need to justify their address space allocations to RIR's so their isn't infinite numbers of sites that a spammer can get.
A /48 can be subdivided into 65K subnets. That is 65 *THOUSAND*... not the 256 IPs that one gets with an IPv4 /24 block. So if a somewhat legit hoster assigns various /64s to DIFFERENT customers of theirs... that is a lot of collateral damage that would be caused by listing at the /48 level, should just one customer be a bad-apple spammer, or just one legit customer have a compromised system one day.
As a provider (ISP or Hosting), you should hand the customers at a minimum a /56, if not a /48. The provider should have at a minimum a /32. If the provider is only giving their customers a /64, then they deserve all the pain they receive.