Hi My problem is related to clientless authentication for printing. We are evaluating if it's worth the trouble on centos. Uppgrading cups is not a problem That i have already solved. Further research also states that kerberos have to be version 1.6.3. This is a big problem. Neither centos 4 nor centos 5 have the required version of kerberos. Compiling my own compile kerberos is not something i want to do! Is it worth it or even possible to upgrade kerberos to 1.6.3 or will we most likely break something else with an upgrade?? No rpms are available and i suppose there's a reason for that. There's no problem compiling cups or kerberos on both platforms. I just wanna find out if it is worth the trouble we will get or if it's possible/recommended to do it?!?!. Best Regards, Thomas References;;; From cups web page.... Using Kerberos Authentication CUPS 1.3 adds Kerberos support which allows you to use a Key Distribution Center (KDC) for authentication on your local CUPS server and when printing to a remote authenticated queue. This document describes how to configure CUPS to use Kerberos authentication and provides helpful links to the MIT help pages for configuring Kerberos on your systems and network. http://www.cups.org/documentation.php/kerberos.html System Requirements The following are required to use Kerberos with CUPS: Heimdal Kerberos (any version) or MIT Kerberos (1.6.3 or newer)