On Mon, 6 Aug 2001, Karl Schmidt wrote:
> If one has a blocking list of IP addresses that contain the 'slash'-bits
> notation(i.e. 192.168.1.0/24) - will that work with exim_dbmbuild to create
> ? What about a cdb file?
>
> I would think there may be some performance issues here.
If you set up a lookup of the form
net24-cdb;/some/file
and your host receives a call from, say 192.168.1.2, then Exim will call
the cdb lookup function with an argument that is the _string_
192.168.1.0/24
This is not a binary number. It is a string representation of the number
and the mask. Just one lookup. Is that clear? Maybe it will help if I
say that if you were using net24-lsearch, the lines in the file could be
192.168.1.0/24
10.9.8.7/24
...
If you want to mix /24 and /dd (where dd is not 24) in the same file,
you have to do multiple lookups.
--
Philip Hazel University of Cambridge Computing Service,
ph10@??? Cambridge, England. Phone: +44 1223 334714.
