On Sat, Mar 14, 2015 at 5:52 PM, Lindsay Haisley <fmouse-cour...@fmp.com>
wrote:
> Spamming engines using IPv4 addresses frequently cycle through IP
> addresses in order to defeat rate limiting filters. These are all
> generally within the same /24 block.
We've seen variations in size between /30 and /16 for IPv4, but yeah, these
are comparatively smaller than what you could expect with IPv6.
Usually, though, you _could_ block by ASN instead of /xx, as some VPS and
colo providers out there don't have a functional anti-spam policy.
> What's the equivalent invariant
> network part generally seen in IPv6 addressed spam? Generally address
> providers will give out a /64 or even a /48 for the asking. We don't
> publish any MX's tied to AAAA records so we don't see any IPv6 spam, but
> I assume it exists.
>
>
It exists, but is for now a fairly rare beast.
My guess is that the comparatively low penetration of IPv6 makes it a
somewhat uninteresting medium for spamming for now.
In general, with IPv6, you can pretend that anything more fine-grained than
a /64 doesn't exist – that's the most detailed network size you are
required to consider for routing purposes.
In the other end, for simplicity's sake, I think we can say that an IPv4
/20 is equivalent to an IPv6 /32 (two quads).
--
Jan
------------------------------------------------------------------------------
Dive into the World of Parallel Programming The Go Parallel Website, sponsored
by Intel and developed in partnership with Slashdot Media, is your hub for all
things parallel software development, from weekly thought leadership blogs to
news, videos, case studies, tutorials and more. Take a look and join the
conversation now. http://goparallel.sourceforge.net/
_______________________________________________
courier-users mailing list
courier-users@lists.sourceforge.net
Unsubscribe: https://lists.sourceforge.net/lists/listinfo/courier-users
