Cisco Catalyst 3750-E - Page 406

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Catalyst 3750-E and 3560-E Switch Software Configuration Guide
OL-9775-08
Chapter 12 Configuring Interface Characteristics
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
pa
ckets:
If you enter a value that is outside the allowed range for the specific type of interface, the value is not
a
ccepted.
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.
Command Purpose
Step 1
configure terminal Enter global configuration mode.
Step 2
system mtu jumbo bytes (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 Table 12-5.
Step 3
system mtu routing bytes (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.
Note For information about the range for bytes, see
Table 12-5.
Step 4
system mtu bytes (Optional) In a mixed hardware stack, change the MTU
size for all Fast Ethernet interfaces on the Catalyst 3750
me
mbers.
The range is 1500 to 1998 bytes; the default is
1500 bytes.
Note This command does not apply to
Catalyst 3560-E witches.
Step 5
end Return to privileged EXEC mode.
Step 6
copy running-config startup-config Save your entries in the configuration file.
Step 7
reload Reload the operating system.
Step 8
show system mtu Verify your settings.