Set network interface to 100 mbit full duplex (eth0) in CentOS
daniel posted this on Sep 21st 2010 under Howto, Linux
Add this line to /etc/sysconfig/networking/devices/ifcfg-eth0
(or any other nic if you need to)
ETHTOOL_OPTS="autoneg off speed 100 duplex full"
Make sure your switch also has this configured this way.