The process of replacing RPMforge packages with Redhats own packages
First we remove rpmforge as package repository

rpm -e rpmforge

This command removes the /etc/yum.repos.d/rpmforge.repo file.

Then we list all packages installed from the RPMforge repository to get an overview of the packages causing problems on the system.

rpm -qa --queryformat %{NAME}-%{VERSION}-%{ARCH}-%{RELEASE}\\n|sort|grep el5.rf

The result

dnsmasq-2.47-x86_64-1.el5.rf
libsndfile-1.0.17-x86_64-1.el5.rf
lftp-3.7.12-x86_64-1.el5.rf
...

The rf ending tells you that these packages are RPMforge packages. This command also tells you if it is 32bit (i386) or 64bit (x86_64) packages. I’ve described the prosess of removing 32- and 64bits packages in a earlier post named Remove duplicate packages when querying the rpm database.

Howto remove 64bit packages

yum remove libsndfile.x86_64

Next we will download the packages we want to replace, in my case dnsmasq

On a RHEL5 system

yumdownloader dnsmasq

If you don’t have yumdownloader in your system you have to install the yum-utils package.

On a RHEL4 system

up2date -d dnsmasq

Then we replace the RPMforge RPM package with Redhats own package

# rpm -Uvh --replacepkgs --oldpackage dnsmasq-2.45-1.el5_2.1.x86_64.rpm
Preparing...                ########################################### [100%]
   1:dnsmasq                ########################################### [100%]

If you don’t use the –oldpackage option you might get an error message like this

package dnsmasq-2.47-1.el5.rf.x86_64 (which is newer than dnsmasq-2.45-1.el5_2.1.x86_64) is already installed

I continued removing RPMForge packages until yum managed to resolve any unresolved dependencies.

1. First lock the account to prevent the user from logging in until the change has been made

# usermod -L <username>

2. Change the password expiration date to 0 to ensure the user changes the password during the next login attempt

# chage -d 0 <username>

3. To unlock the account after the change do the following:

# usermod -U <username>

Redhat has put a lot of effort in their documentation and even allow you to download them as PDF documents.

The documentation below is for RHEL5.2

These documents is a great resource if you plan to become a RHCT or RHCE.

Convert a date (YYYYMMDD) to unix timestamp

# date -d "20080913" +%s
1221256800

Edit /etc/sysconfig/network and change

NETWORKING_IPV6=no

Edit /etc/modprobe.conf and add these lines

alias net-pf-10 off
alias ipv6 off

Stop the ipv6tables service

# service ip6tables stop

Disable the ipv6tables service

# chkconfig ip6tables off

IPv6 will be disabled after the next reboot.

Edit
This also works on RHEL6/CentOS6