Cisco Systems WSC2960X48TDL manual How to Configure MTU Sizes, Configuring the System MTU

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Configuring System MTU

How to Configure MTU Sizes

the system mtu 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.

•Frames sizes that can be received by the switch CPU are limited to 1998 bytes, no matter what value was entered with the system mtu or system mtu jumbo commands. Although frames that are forwarded are typically not received by the CPU, in some cases, packets are sent to the CPU, such as traffic sent to control traffic, SNMP, or Telnet.

Note If Layer 2 Gigabit Ethernet interfaces are configured to accept frames greater than the 10/100 interfaces, jumbo frames received on a Layer 2 Gigabit Ethernet interface and sent on a Layer 2 10/100 interface are dropped.

How to Configure MTU Sizes

Configuring the System MTU

Beginning in privileged EXEC mode, follow these steps to change the MTU size for all 10/100 or Gigabit Ethernet interfaces:

SUMMARY STEPS

1.configure terminal

2.system mtu bytes

3.system mtu jumbo bytes

4.end

5.copy running-config startup-config

6.reload

7.show system mtu

DETAILED STEPS

	Command or Action	Purpose
Step 1	configure terminal	Enters global configuration mode.
	Example:
	Switch# configure terminal

	Catalyst 2960-X Switch Interface and Hardware Component Configuration Guide, Cisco IOS Release 15.0(2)EX
72	OL-29034-01

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Contents Americas Headquarters First Published July 10Page N T E N T S Contents Configuring Auto-MDIX41 Configuring System MTU Configuring EEE Viii Document Conventions Convention DescriptionBold font Vertical bars ElementReader Alert Conventions Obtaining Documentation and Submitting a Service Request Related DocumentationXii Information About Using the Command-Line Interface Command ModesThis chapter contains the following topics Mode Access Method Prompt Exit Method About This Mode ConfigureQuit Ctrl-ZUsing the Help System Command or Action Purpose StepMode HelpUnderstanding Abbreviated Commands No and default Forms of CommandsCLI Error Messages How to Use the CLI to Configure Features Configuration LoggingConfiguring the Command History Error Message MeaningChanging the Command History Buffer Size Recalling CommandsCommand or Action Enabling and Disabling Editing Features Disabling the Command History FeaturePrivileged Exec mode Terminal no historyEditing Commands through Keystrokes Editing Command Lines That Wrap Searching and Filtering Output of show and more Commands Access-listShow more command begin include exclude regular-expression Show more command begin include excludeCommand or Action Example OL-29034-01 Finding Feature Information Information About Configuring Interface CharacteristicsInterface Types This module contains the following topicsSwitch Ports Port-Based VLANsSwitch Virtual Interfaces Trunk PortsPower over Ethernet Ports EtherChannel Port GroupsUsing the Switch USB Ports USB Mini-Type B Console PortInterface Connections USB Type a PortsInterface Configuration Mode Connecting VLANs with the SwitchDefault Ethernet Interface Configuration FeatureDefault Setting Layer 2 or switching mode switchport command VLANs 1Interface Speed and Duplex Mode Speed and Duplex Configuration GuidelinesIeee 802.3x Flow Control How to Configure Interface Characteristics Configuring Interfaces ProcedureGigabit Ethernet port 1 on switch 1 is selected Either gigabitethernet 1/0/1Configure terminal Adding a Description for an InterfaceDescription string Show interfaces interface-id descriptionConfiguring a Range of Interfaces Configure terminal Enters global configuration modeInterface range port-rangemacro Configuring and Using Interface Range Macros Verifies the configuration of the interfaces in the rangeDefine interface-range macroname Configuring Ethernet Interfaces Setting the Interface Speed and Duplex ParametersInterface range macro macroname Speed 10 100 1000 auto 10 NonegotiateConfiguring Ieee 802.3x Flow Control Command or Action PurposeConfiguring SVI Autostate Exclude End Returns to privileged Exec modeEnter interface configuration mode Switchport autostate exclude Shutting Down and Restarting the InterfaceAn SVI line state up or down Interface vlan vlan-id gigabitethernet interface-idConfiguring the Console Media Type This configuration applies to all switches in a stackConfigure terminal Line console Media-type rj45 End Shutdown Shuts down an interfaceConfiguring the USB Inactivity Timeout Configure terminal Enters the global configuration modeMonitoring Interface Characteristics Command PurposeShow interfaces interface-id status err-disabled Show interfaces interface-id switchportClearing and Resetting Interfaces and Counters Configuration Examples for Interface Characteristics Identifying Interfaces on a Stack-Capable Switch ExamplesConfiguring a Range of Interfaces Examples Adding a Description to an Interface ExampleConfiguring and Using Interface Range Macros Examples Setting Interface Speed and Duplex Mode ExampleConfiguring the Console Media Type Example Configuring the USB Inactivity Timeout Example To disable the configuration, use these commandsStandards and RFCs Standard/RFC NoneCisco IOS Release 15.02EX This feature was introduced Technical Assistance Description LinkRelease Modification OL-29034-01 Prerequisites for Auto-MDIX Restrictions for Auto-MDIXThis module contains the following sections Information about Configuring Auto-MDIX How to Configure Auto-MDIXConfiguring Auto-MDIX on an Interface Auto-MDIX on an InterfaceMonitoring Auto-MDIX Example for Configuring Auto-MDIX This example shows how to enable auto-MDIX on a portPrerequisites for Ethernet Management Ports Information about the Ethernet Management PortEthernet Management Port Direct Connection to a Switch Supported Features on the Ethernet Management PortHow to Configure the Ethernet Management Port Disabling and Enabling the Ethernet Management PortAdditional References What to Do NextBootloader commands Related TopicMIBs Document TitleOL-29034-01 Configuring LLDP, LLDP-MED, and Wired Location Service Lldp and Cisco Switch Stacks Lldp Supported TLVsLldp and Cisco Medianet LLDP-MED Supported TLVs Wired Location Service Default Lldp Configuration Configuration GuidelinesConfigure terminal Lldp run Lldp run Enables Lldp globally on the switchLLDP, and enter interface configuration mode Enabling LldpConfiguring Lldp Characteristics Lldp transmit Enables the interface to send Lldp packetsLldp receive Enables the interface to receive Lldp packets Show lldp Verifies the configurationSwitchconfig# lldp holdtime Configuring LLDP-MED TLVs Command or Action Purpose StepLldp med-tlv-select End Copy running-config startup-config Lldp med-tlv-select Specifies the TLV to enableConfiguring Network-Policy TLV Configuration mode. The range is 1 toVoice voice-signalingvlan vlan-idcos Dscp dvalue none untaggedConfiguring Location TLV and Wired Location Service Show network-policy profile Verifies the configurationUse one of the following WayExit Returns to global configuration mode Information, and enter interface configuration modeUse one of the following Verifies the configuration Enters location information for an interfaceEnabling Wired Location Service on the Switch Command or Action Purpose ExampleConfiguring Network-Policy TLV Examples Nmsp enable Enables the Nmsp features on the switchNmsp notification interval attachment location Command Description Civic location OL-29034-01 Information about the MTU System MTU GuidelinesHow to Configure MTU Sizes Configuring the System MTUConfiguration Examples for System MTU Show system mtu Verifies your settingsReload Reloads the operating system Additional References for System MTU Configuring PoE Restrictions for PoEPower over Ethernet Ports Information about PoESupported Protocols and Standards Powered-Device Detection and Initial Power Allocation ClassPower Management Modes Power Monitoring and Power Policing Maximum Power Allocation Cutoff Power on a PoE Port How to Configure PoE Configuring a Power Management Mode on a PoE PortBudgeting Power for Devices Connected to a PoE Port Show power inlineNever static max max-wattage Budgeting Power to All PoE ports No cdp run Optional Disables CDPBudgeting Power to a Specific PoE Port Configure terminal No cdp runConfiguring Power Policing Specifies the physical port to be configured, and enterPower inline consumption wattage Power inline police actionlog errdisable Exit Show power inline police Show errdisable recoveryConfiguration mode Power inline police actionlog errdisablePower inline police action log-Generates a syslog message While still providing power to the portDown the port and puts the port in the error-disabled state Monitoring Power Status Configuration Examples for Configuring PoEBudgeting Power Example Information About EEE EEE OverviewHow to Configure EEE Default EEE ConfigurationEEE is disabled by default Restrictions for EEESpecifies the interface to be configured, and enter Power efficient-ethernet autoCommand Monitoring EEEConfiguration Examples for Configuring EEE This example shows how to enable EEE for an interfaceThis example shows how to disable EEE for an interface Feature History and Information for Configuring EEE OL-29034-01 D E PoE