# ethtool -s eth0 autoneg on
# ethtool -s eth0 speed 10 duplex half autoneg off
# ethtool -s eth0 speed 100 duplex full autoneg off
# vi /etc/sysconfig/network-scripts/ifcfg-eth0
ETHTOOL_OPTS="speed 100 duplex full autoneg off"
하지만 1G NIC는 권장 하지 않는다 그래서 변경이 안된다.
참고 링크 : https://access.redhat.com/solutions/20881
Using the ethtool utility one cannot set autoneg off for Gigabit ethernet cards
근본 원인
This error comes up since auto-negotiation is a must for gigabit ethernet interfaces, ie.. "Autonegotiation is a requirement for using 1000BASE-T according to the standard."
It is not recommended to disable auto negotiation on gigabit interfaces. Gigabit Ethernet is a completely different protocol from 10baseT and 100baseTX, just BARELY similar enough to run over the same kinds of network cables. Some drivers/firmware will even silently ignore the change if auto-negotiation is disabled.
