At work we only have 6 licenses for RHEL (three boxes at RHEL 4 and three at RHEL 5.1). I'd like to learn more about yum and install the RHEL 5.1 patches. I have a spare laptop and wonder if I can use yum with Redhat network to test updates and setup a repository. The reason is all RHEL 5.1 boxes are in production now. I don't want to remove one RHEL 5.1 from redhat network, but it appears that is the only way?

Centos is RHEL with the logos removed. Their updates usually are up within a couple of days of RHEL. You can use Centos' repos on RHEL or in your case you could install Centos to the laptop, learn how to set up a local repo with it(using Centos' repos), and then apply what you learn using RHEL's repos.

We do something similar to what you are asking - basically a poor-man's satellite server.

Every quarter, I download all the available RHEL patches for a specific architecture (x86, x64) with a script like:
#!/bin/bash
for varPACKNAME in `up2date --showall`; do
varCOMPLETE="$varCOMPLETE $varPACKNAME"
done
up2date --get $varCOMPLETE

Then I used createrepo to create the needed repo files and copy all of this to an FTP location available to all my servers. I might call this may2008 packages.

Then, after testing and as I get approval to apply the latest patches to each server, I change their /etc/yum.conf to something similar to:
[May2008]
name=RHEL4-May2008 Updates i386
baseurl=ftp://usernameassword@ftpserver/may2008/i386/
enabled=1
gpgcheck=0
protect=0


so that they look at the new location. The reason I do this is so I can have a consistant and static group of packages each quarter that can be tested against and then applied to prod. servers. I currently only use RHEL4 servers and this involved getting yum.rpm's external to RH to install. We do have RHEL licenses for each server still and each is still registered with RHN, though this is not needed to make the solution work. This is a requirement of using RHEL software as opposed to Centos.

wow thanks a million! When I get more time I will try to work on this.