Cisco Catalyst 4500 Series Software Configuration Guide

Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS
Chapter 9 Configuring Interfaces
Configuring Optional Interface Features
Configuring MTU Sizes
To configure the MTU size, perform this task:
Note When you remove a line card, and then reinsert the card, some or all of the MTU values configured on
the ports of that line card may be unconfigured. This occurs if the system wide limit of 32 different
MTUs is reached while the card is removed. Upon reinserting the line card, the system attempts to
reapply the MTU configuration on the ports. If this attempt fails, the MTU values are set to the default.
Note When configuring the MTU size for VLAN interfaces and Layer 3 and Layer 2 Ethernet ports, note that
the supported MTU values are from 1500 to 9198 bytes.
This example shows how to configure the MTU size on Gigabit Ethernet port 1/1:
switch# conf terminal
switch(config)# interface gi1/1
switch(config-if)# mtu 9198
switch(config-if)# end
switch(config)# end
switch# show interface gigabitethernet 1/2
GigabitEthernet1/2 is administratively down, line protocol is down
Hardware is C6k 1000Mb 802.3, address is 0030.9629.9f88 (bia 0030.9629.9f88)
MTU 9216 bytes, BW 1000000 Kbit, DLY 10 usec,
<...Output Truncated...>
switch#
Interacting with Baby Giants
The baby giants feature, introduced in Cisco IOS Release 12.1(12c)EW, uses the global command system mtu size to set the
global baby giant MTU. This feature also allows certain interfaces to support Ethernet payload size of up to 1552 bytes.
Both the system mtu command and the per-interface mtu command can operate on interfaces that can support jumbo frames,
but the per-interface mtu command takes precedence.
Command Purpose
Step 1
Switch(config)# interface {{vlan vlan_ID} |
{{type
1
slot/port} | {port-channel
port_channel_number} slot/port}}
1. type = fastethernet, gigabitethernet, or tengigabitethernet
Selects the interface to configure.
Step 2
Switch(config-if)# mtu mtu_size
Configures the MTU size.
Switch(config-if)# no mtu
Reverts to the default MTU size (1500 bytes).
Step 3
Switch(config-if)# end
Exits configuration interface mode.
Step 4
Switch(config)# end
Exits configuration mode.
Step 5
Switch# show running-config interface
[{fastethernet | gigabitethernet} slot/port]
Verifies the running configuration.

Cisco Catalyst 4500 Series Specifications

General

Series	Catalyst 4500 Series
Category	Switch
Layer Support	Layer 2, Layer 3
Form Factor	Modular chassis
Stackable	No
Chassis Slots	3, 6, 7, 10
Power Supply Options	AC, DC
Redundancy	Power supply, Supervisor engine
Network Management	Cisco IOS Software CLI, SNMP, Cisco Prime Infrastructure
Features	Security, QoS
Port Density	Up to 384 ports per chassis
Security Features	802.1X, ACLs, DHCP Snooping, Dynamic ARP Inspection, IP Source Guard
Supervisor Engine	8-E