Collection of FAQ answers I seem to be repeating...
Last update: 20-Nov-1997,  <mea@nic.funet.fi>

Q:	- My database lookups start to become erratic until I restart
	  the router processes

A:	Most likely you have copied/modified data in place to existing
	database file(s).  A definite no-no!

	The correct way is to create the new edition of the database
	on a temporary file in the same directory as the active one
	resides, but with different name (Shell '$$' expression helps
	here).  Then move (unix mv command, or rename() system call)
	the file(s) to the old name.

	In case of dual-file databases, move first the DIR file, and
	then the PAG file. (DBM/NDBM databases)

	The system has utility script "newdb" to facilitate this, but
	it does certain set of assumptions on filenames and database
	types -- something you might not want to do in quite the same way.


	The reason there is no explicite file interlocking is that
	1) carefull file handling can get by without it,  2) it is
	extra complicated code that can go wrong.

	There could be ways with at least GDBM and BSD DB to have
	multiple modifiers on the same database, but it is rather
	complex code with several system calls per database access...

Q:	- "EHLO greeting does not send FQDN";
	- My SMTP transport agent says "EHLO host", when it should say
	  "EHLO host.domain", what is wrong ?

A:	The way the smtp transporter finds out what it should tell
	at the HELO/EHLO is to do IP reversal lookup on the address
	that the local socket has.  (For example for hosts with
	multiple network interfaces each may have different name..)

	Sometimes people configure things so that their system does
	IP reversal lookup initially from /etc/hosts file, and in it
	they have written something like this:
		1.2.3.4 host host.domain

	The first white space separated field is IP address, the second
	is the canonic (FQDN) address, and possible others are aliases.

	This line should read:
		1.2.3.4 host.domain host


Q:	- The system scrambles headers like this:
		From daemon@mail.siol.net Thu Jan  2 09:55:21 1997
		Sender:  <daemon@mail.siol.net>
		From:   Tomaz Borstnar <tomaz.test@siol.net>
		X-Sender: Tomaz Borstnar <tomaz.test@siol.net>
		Return-Path: <daemon@mail.siol.net>
	  what is going on ?

A:	It is about ZMailer's "trusted" group -- or lack of it.
	The INSTALL file speaks of  /etc/group: zmailer -group entry
	The usual members of that ("zmailer") group are:
		root,daemon,uucp

	With Majordomo in the system and running at its own userid,
	you must add it to the trusted set as well:
		root,daemon,uucp,majordom

	Bear in mind that some systems pull the "/etc/groups" from
	external databases (NIS/NIS+), and your local host may or
	may not use the data at the /etc/groups file before pulling
	things (or nor pulling) from the NIS/NIS+...
	In other words: Your Mileage May Vary