The Most Frequently Asked Questions

LPRng Reference Manual: 24 Sep 2004 (For LPRng-3.8.28)
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# Chapter 20. The Most Frequently Asked Questions

In this section, the Most Frequently Asked Questions have been placed, together with their answers. You may notice that some questions have the same answer, but the symptoms appear differently.

Some of these answers will reference other material in this FAQ, or the LPRng man pages.

# 20.1. Why do I get malformed from address errors?

This is the number one question asked by most LPRng users who try to use LPRng with network printers or other systems supporting RFC1179 printing. For details about LPRng and RFC1179, see RFC1179 and LPRng.

The malformed from address error is usually reported when trying to send a print job from LPRng to other BSD lpr or RFC1179 lpr implementations, or with network connected printers that have a built in lpd server. This is due to the following RFC1179 rule:

> Servers originate a connection from ports in the range 721-731.

WHY? These are a subset of the 'reserved' ports in UNIX, and normal users cannot open connections from them. This provides a small amount of security from UNIX users on the host 'spoofing' a server.

IMPLICATION: in order to do use a reserved port, the program must have root privileges. This means the LPR, lpd, lpq, etc., programs must be installed SUID root. This can open up a can of worms with regard to security, but LPRng has been designed to take as much paranoid care as possible to avoid problems.

WHAT TO DO: When installing LPRng you will need to install the executables SUID root. In the `src/Makefile`, you can remove the comment from the line

        PERMS=SUID_ROOT_PERMS

and then do make install. This will install the executables SUID, and owned by root.

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