[rbldnsd] Re: rbldnsd support for IPv6 entries

[Michael Tokarev]

[Cc'ing rbldnsd mailinglist.  Hope you don't mind]

Benoit Panizzon wrote:
> Hi Michael
> 
> Are there any plans to support IPv6 RBL Entries with rbldnsd in near future?

Well... IPv6 covers *much* larger space than IPv4, and is "larger" too,
in various aspects (larger, 128 vs 32 bits, addresses, 16 vs 4 "nibbles"
in reverse query, etc).  Ofcourse, as IPv6 isn't (yet) deployed that
widely as IPv4, it isn't here yet to worry about sizes right now.. may
be.

The problem is, I don't know how to represent IPv6 internally, to be
compact and efficient.  Also, I don't know if it's worth the effort to
list ranges smaller than /64, but for things like open relays or
proxies, /128 seems to be a way to go.

Perhaps "ip6trie" dataset, similar to existing ip4trie, will be appropriate.

In short: for that to work, we need good internal representation of this
stuff, algorithms, and some usage scenario "research".  This has not been
done yet.  More, as I don't have IPv6 here, this all is of rather theoretical
interest to me -- I can't even test it right now, as I know too little
details about IPv6, not even how to configure an interface address ;)

> We use IPv6 enabled mailserver and would like to be able to blacklist Adresses 
> that sent us spam via IPv6.

This can be useful.  Assuming there is IPv6 support in rbldnsd, how'd you
use it in your case?  Do you list neranges, or individual /128 adddresses?
How many of them do you see?  And, is there any spam in IPv6 space, at all,
in the first place? ;) (I don't think "regular" spammers seriously (or at
all) looking at IPv6 nowadays - too much work without any good reason).

Thanks.

/mjt