Enabling Jumbo Frames
A jumbo frame is an Ethernet frame with a payload greater than the standard maximum transmission unit (MTU) of 1,500 bytes. Jumbo frames are used on local area networks that support at least 1 Gbps and can be as large as 9,000 bytes.
Jumbo frames need to be configured the same on the entire network path: source device > switch > router > switch > destination device. If the entire chain isn't set the same, it defaults to the lowest setting along the chain. IBM Cloud® has network devices set to 9,000 currently. For best performance, all customer devices need to be set to the same 9,000 value.
Enabling Jumbo Frames
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Edit the network configuration file for eth0 interface.
- CentOS, RHEL, Fedora users edit
/etc/sysconfig/network-scripts/ifcfg-eth0
.# vi /etc/sysconfig/network-scripts/ifcfg-eth0
- Debian and Ubuntu users edit
/etc/network/interfaces
.
- CentOS, RHEL, Fedora users edit
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Append the following configuration directive, which specifies the size of the frame in bytes.
- CentOS, RHEL, Fedora
MTU 9000
- Debian and Ubuntu
MTU=9000
- CentOS, RHEL, Fedora
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Close and save the file. Restart the Interface eth0.
# /etc/init.d/networking restart
This action causes a brief loss of network connectivity.