# ethtool -s eth0 speed 100 duplex full autoneg off

These settings are active until you reboot the machine or restart the network.

In order to keep this change on each system reboot, append the following line in the following Redhat file /etc/sysconfig/network-scripts/ifcfg-eth0

ETHTOOL_OPTS="speed 100 duplex full autoneg off"

An alternative tool to use to change the settings is mii-tool.

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.

alias net-pf-10 ipv6

Add the following line to /etc/modprobe.conf

alias net-pf-10 off

Reboot the system. IPv6 is now disabled.

To re-enable IPv6, remove the alias net-pf-10 off line from /etc/modprobe.conf and reboot the machine.

I’ve also made a post about how to disable IPv6 on RHEL5.