Problem with whitelisting CIDR blocks with greylisting and IPv6

Irelann Anderson
Thu Jan 29 14:41:02 UTC 2009

We've been experimenting with IPv6 for years, but real deployment has been
going on for only a few months.  I recently noticed we had internal mail
clients and servers that were getting greylisted and I wanted to whitelist
our entire IPv6 block for now.  My initial go at this was to add the
following line to grey_whitelist:

ok      IP      2610:48::/32

However dbclean produced the message:

CIDR block length in 2610:48::/32 too large in line 24 of

On looking at the source code, it appears that I can't specify a prefix
shorter than /112.  Since the smallest network you would normally use in
IPv6 has a prefix of /64, that makes whitelisting by network block a bit
difficult in IPv6.

Am I reading this wrong  or is there a way to do this that I've missed.

Irelann Kerry Anderson          phone:    (207)561-3508
Systems and Operations
Information Technology Services
University of Maine System
5752 Neville Hall
Orono, Maine 04469-5752
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