Forcing Full Duplex on CentOS/Redhat

Some times network connection in CentOS shows half duplex, there is a way to force it to full duplex.





To force 100mb full duplex and turn off autonegotiation on network interface ‘eth0’


The output of the ‘ethtool eth0’ should now look like this:



NOTE: This change will be lost on the next reboot.


To make the change permanent, you need to edit the config file for the network interface. These live in /etc/sysconfig/network-scripts. Each interface will have a file called ‘ifcfg-ethX’, ie. for ‘eth0’ the file would be ‘ifcfg-eth0’. To make it so that when the machine is rebooted it comes up with the network interface at 100mb full-duplex, add the following line to this file:


Please follow and like us:
About shk

shk is a DevOps engineer with more than 12 years of experience in different organizations. He enthusiastic about learning new technologies and shares his knowledge through his blogs.

Comment Policy:

Your words are your own, so be nice and helpful if you can. Please, only use your real name, not your business name or keywords. Using business name or keywords instead of your real name will lead to the comment being deleted. Anonymous commenting is not allowed either. Limit the amount of links submitted in your comment. We accept clean XHTML in comments, but don't overdo it please.

Tell us what you're thinking...

All comments are moderated.

* Denotes required field.



Previous Post:
Next Post: