How to enable jumbo frame in linux

Linux MTU Change Size

We’ve gigabit networks, and large maximum transmission units (MTU) sizes (JumboFrames) can provide better network performance for our HPC environment. How do I change MTU size under Linux?

You need support in both network hardware and card in order to use JumboFrames. If you want to transfer large amounts of data at gigabit speeds, increasing the default MTU size can provide significant performance gains.


Changing the MTU size with ifconfig command

In order to change the MTU size, use /sbin/ifconfig command as follows:


ifconfig ${Interface} mtu ${SIZE} up
ifconfig eth1 mtu 9000 up


Note this will only work if supported by both the network nterface card and the network components such as switch.


Changing the MTU size permanently under CentOS / RHEL / Fedora Linux


Edit /etc/sysconfig/network-scripts/ifcfg-eth0, enter

# vi /etc/sysconfig/network-scripts/ifcfg-eth0


Add MTU, settings:

MTU="9000"


Save and close the file. Restart networking:


# service network restart


Note for IPV6 set dedicated MTU as follows:


IPV6_MTU="1280"



Changing the MTU size permanently under Debian / Ubuntu Linux

Edit /etc/network/interfaces, enter:

# vi /etc/network/interfaces


Add mtu as follows for required interface:

mtu 9000


Save and close the file. Restart the networking, enter:

# /etc/init.d/networking restart


Changing the MTU size permanently 


Edit /etc/rc.local and add the following line:

/sbin/ifconfig eth1 mtu 9000 up