Your software release
may not support all the features documented in this module. For the latest
caveats and feature information, see Bug Search Tool and the release notes for
your platform and software release. To find information about the features
documented in this module, and to see a list of the releases in which each
feature is supported, see the feature information table at the end of this
Use Cisco Feature
Navigator to find information about platform support and Cisco software image
support. To access Cisco Feature Navigator, go to
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When configuring the
system MTU values, follow these guidelines:
switch does not support the MTU on a
If you enter the
system mtubytes global configuration command, the command
does not take effect on the
switch. This command only affects the system
MTU size on Fast Ethernet switch ports.
The default maximum
transmission unit (MTU) size for frames received and transmitted on all
interfaces is 1500 bytes. You can increase the MTU size for all interfaces
operating at 10 or 100 Mb/s by using the
global configuration command. You can increase the MTU size to support jumbo
frames on all Gigabit Ethernet interfaces by using the
system mtu jumbo
global configuration command.
Gigabit Ethernet ports are not affected by the system mtu
command; 10/100 ports are not affected by the system mtu jumbo command. If you
do not configure the system mtu jumbo command, the setting of the system mtu
command applies to all Gigabit Ethernet interfaces.
This example shows
how to set the maximum packet size for a Gigabit Ethernet port to 7500 bytes:
Switch(config)# system mtu 1900Switch(config)# system mtu jumbo 7500Switch(config)# exit
If you enter a value
that is outside the allowed range for the specific type of interface, the value
is not accepted. This example shows the response when you try to set Gigabit
Ethernet interfaces to an out-of-range number:
This is an example
of output from the
show system mtu
Switch# show system mtu
Global Ethernet MTU is 1500 bytes.
References for System MTU
Error Message Decoder
To help you research and resolve system error messages in this release, use the Error Message Decoder tool.
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