mynetworks via LDAP lookup

2 msg	postmap header_checks error
10 msg	mailbox_command (dovecot lda) stopped working, ...

mynetworks via LDAP lookup
\ Ruud Baart (24 Jan 2008)
. \ Rolf E. Sonneveld (24 Jan 2008)
. . \ Ruud Baart (24 Jan 2008)
. . . \ Noel Jones (24 Jan 2008)
. \ (Wietse Venema) (24 Jan 2008)

7 msg	Local recipient table in LDAP problem
2 msg	proxy_read_maps
1 msg	smtpd_restriction_class and it's lookup
8 msg	Message Rejected
12 msg	Customize to filter attachment ?
2 msg	Relay question
14 msg	unnecessary routing?
4 msg	do not use 'reject_maps_rbl'?
9 msg	Fwd: Postfix in OpenVZ.
2 msg	bypass body_checks for local mail?
4 msg	catchall with relay_recipient_maps
4 msg	'Name server failure' is output
3 msg	smtp_sasl_password_maps lookups
16 msg	Postfix Queues on a Ram Disk
15 msg	sendmail compared to smtp sending
3 msg	Postfix does not recognize remote emails
2 msg	How to disable SSLv2 on smtpd opportunistic TLS?

Subject:	mynetworks via LDAP lookup
Group:	Postfix-users
From:	Ruud Baart
Date:	24 Jan 2008

A normal mynetworks parameters looks like:
mynetworks = $config_directory/mynetworks
and in this file are all the networks listed:
192.168.1.0/24
172.23.10.0/24
127.0.0.0/8
217.1.2.3/28

Is it possible to replace this lookup with a LDAP lookup?

I tried this:
mynetworks = ldap:$config_directory/ldap/mynetworks.cf

And the query is:
server_host = ldap://localhost
bind_dn = cn=Postfix,dc=example,dc=com
bind_pw = secret
search_base = ou=Networks,cn=Postfix,dc=example,dc=com
query_filter = (ipNetworkNumber=%s)
result_attribute = ipNetworkNumber

With
postmap -q 192.168.1.0/24 ldap:./mynetworks.cf
I get result back. But with
postmap -q 192.168.1.1 ldap:./mynetworks.cf
I get no result back although it is an allowed network address.

Perhaps it is simple but I can't find a proper solution. Does someone
give me a hint how I can lookup specific IP numbers and storing IP
ranges in LDAP?

Regards
R.J. Baart