====== Maximum Transmission Unit (MTU) ======

The MTU is the size of the largest protocol data unit (PDU) that can be communicated in a single network layer transaction. ([[https://en.wikipedia.org/wiki/Maximum_transmission_unit|source]])

Usually, for //Jumbo Frames// the maximum MTU size is 9000 bytes and the default is 1500 bytes.

===== Linux ======

==== set MTU ====
<code bash>ip link set eth0 mtu 9000</code>

==== set MTU permanently ====
=== Fedora ===
<file INI /etc/sysconfig/network-scripts/ifcfg-enp0s1>MTU=9000</file>


==== check MTU ====
<code bash>ping -M do -s 8972 [destination IP]</code>

There is an overhead of 8 bytes for ICMP headers and 20 bytes for Ethernet header, so the MTU is 28 bytes larger than the figure you establish through the method above. So to test for MTU of 9000, you actually need to set your ping packet size to 9000-28 = 8972.