If "ifconfig" or "/proc/net/dev" shows you are getting packet errors and collisions, check that the network interface is not running at half-duplex. Full duplex would enable packets to flow in both direction in and out simultaneously.
ethtool eth0To turn on full duplex:
ethtool -s eth0 speed 100 duplex full autoneg offVerifying with `mii-tool eth0` should produce:
eth0: 100 Mbit, full duplex, link okMake this permanent by editing "/etc/sysconfig/network-scripts/ifcfg-eth0" and add:
ETHTOOL_OPTS="speed 100 duplex full autoneg off"