Cisco Catalyst 3750-E Software Configuration Manual page 406

Configuring the System MTU
The upper limit of the system routing MTU value is based on the switch or switch stack configuration
and refers to either the currently applied system MTU or the system jumbo MTU value. For more
information about setting the MTU sizes, see the system mtu global configuration command in the
command reference for this release.
Beginning in privileged EXEC mode, follow these steps to change the MTU size for switched and routed
packets:
Command
Step 1 configure terminal
Step 2 system mtu jumbo bytes
Step 3
system mtu routing bytes
Step 4 system mtu bytes
Step 5
end
Step 6 copy running-config startup-config
Step 7 reload
Step 8 show system mtu
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 how to set the maximum packet size for a Gigabit Ethernet port to 7500 bytes:
Switch(config)# system mtu jumbo 7500
Switch(config)# exit
Switch# reload
This example shows the response when you try to set Gigabit Ethernet interfaces to an out-of-range
number:
Switch(config)# system mtu jumbo 25000
% Invalid input detected at '^' marker.
Catalyst 3750-E and 3560-E Switch Software Configuration Guide
12-36
Chapter 12
Purpose
Enter global configuration mode.
(Optional) Change the MTU size for all Gigabit
Ethernet and 10-Gigabit Ethernet interfaces on the
switch or the switch stack. For information about the
range for bytes, see
(Optional) Change the system MTU for routed ports.
You can also set the maximum MTU to be advertised by
the routing protocols that support the configured MTU
size. The system routing MTU is the maximum MTU
for routed packets and is also the maximum MTU that
the switch advertises in routing updates for protocols
such as OSPF.
For information about the range for bytes, see
Note
Table 12-5.
(Optional) In a mixed hardware stack, change the MTU
size for all Fast Ethernet interfaces on the Catalyst 3750
members.
The range is 1500 to 1998 bytes; the default is
1500 bytes.
This command does not apply to
Note
Catalyst 3560-E witches.
Return to privileged EXEC mode.
Save your entries in the configuration file.
Reload the operating system.
Verify your settings.
^
Configuring Interface Characteristics
Table 12-5.
OL-9775-08