Cisco Catalyst 3560-X

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Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-25303-03
Chapter 1 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.
To change the MTU size for switched and routed packets, follow these steps beginning in privileged
EXEC mode:
Table 1-5 System MTU Values
Configuration system mtu command system jumbo mtu command system routing mtu command
Standalone Catalyst
3750-X, 3750-E, 3560-X
or 3560-E switch or
Catalyst 3750-X-only or
Catalyst 3750-E-only
stack
You can enter the command on
on a Catalyst 3750-X,
Catalyst 3750-E, Catalyst
3560-X, or Catalyst 3560-E
switch, but system MTU value
does not take effect.
1
1. If you use the system mtu bytes command on a Catalyst 3750-X or 3750-E member in a mixed hardware stack, the setting takes effect on the Fast Ethernet
ports of Catalyst 3750 members.
Use the system mtu jumbo
bytes command.
The range is from 1500 to 9198
bytes.
Use the system mtu routing
bytes command.
The range is from 1500 to the
system jumbo MTU value (in
bytes).
2
2. The system routing MTU value is the applied value, not the configured value.
Mixed hardware stack Use the system mtu bytes
command, which takes effect
only on Catalyst 3750
members.
1
The range is from 1500 to 1998
bytes.
Use the system mtu jumbo
bytes command.
The range is from 1500 to 9000
bytes.
Use the system mtu routing
bytes command.
The range is from 1500 to the
system MTU value (in bytes).
2
Catalyst 3750-only stack
Catalyst 3750 switch
Catalyst 3560 switch
Use the system mtu bytes
command.
The range is from 1500 to 1998
bytes.
Use the system mtu jumbo
bytes command.
The range is from 1500 to 9000
bytes.
Use the system mtu routing
bytes command.
The range is from 1500 to the
system MTU value (in bytes).
Command Purpose
Step 1
configure terminal Enters global configuration mode.
Step 2
system mtu jumbo bytes (Optional) Changes 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 1-5.
Step 3
system mtu routing bytes (Optional) Changes 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 Table 1-5.
Note This command is not supported on switches
running the LAN base feature set.