Table Of Contents

M Commands

monitor erspan origin ip-address

monitor session

mtu

M Commands

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This chapter describes the system management commands that begin with M.

monitor erspan origin ip-address

To configure the Encapsulated Remote Switched Port Analyzer (ERSPAN) origin IP address, use the monitor espan origin ip-address command. To remove the ERSPAN origin IP address configuration, use the no form of this command.

monitor erspan origin ip-address ip-address [global]

no monitor erspan origin ip-address ip-address [global]

Syntax Description

ip-address	IP address.
global	(Optional) Specifies the default virtual device context (VDC) configuration across all VDCs.

Command Default

None

Command Modes

Global configuration mode

Command History

Release	Modification
5.2(1)N1(1)	This command was introduced.

Usage Guidelines

When you change the origin IP address in the default VDC, it impacts all the sessions.

This command does not require a license.

Examples

This example shows how to configure the ERSPAN origin IP address:

switch# configure terminal

switch(config)# monitor erspan origin ip-address 10.1.1.1 global

switch(config)# 

This example shows how to remove the ERSPAN IP address:

switch# configure terminal

switch(config)# no monitor erspan origin ip-address 10.1.1.1 global

switch(config)#

Related Commands

Command	Description
monitor session	Configures a SPAN or an ERSPAN session.

monitor session

To create a new Ethernet Switched Port Analyzer (SPAN) or an Encapsulated Remote Switched Port Analyzer (ERSPAN) session configuration for analyzing traffic between ports or add to an existing session configuration, use the monitor session command. To clear SPAN or ERSPAN sessions, use the no form of this command.

monitor session {session-number [shut | type {local | erspan-source} | all shut}

no monitor session {session-number | all} [shut]

Syntax Description

session-number	SPAN session to create or configure. The range is from 1 to 18.
all	Specifies to apply configuration information to all SPAN sessions.
shut	(Optional) Specifies that the selected session will be shut down for monitoring.
type	(Optional) Specifies the type of session to configure.
local	Specifies the session type to be local.
erspan-source	Creates an ERSPAN source session.

Command Default

None

Command Modes

Global configuration mode

Command History

Release	Modification
5.2(1)N1(1)	This command was introduced.

Usage Guidelines

To ensure that you are working with a completely new session, you can clear the desired session number or all SPAN sessions.

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Note The Cisco Nexus 6000 switch supports two active SPAN sessions. The Cisco Nexus 5548 Switch supports four active SPAN sessions. When you configure more than two SPAN sessions, the first two sessions are active. During startup, the order of active sessions is reversed; the last two sessions are active. For example, if you configured ten sessions 1 to 10 where 1 and 2 are active, after a reboot, sessions 9 and 10 will be active. To enable deterministic behavior, explicitly suspend the sessions 3 to 10 with the monitor session session-number shut command.

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After you create an ERSPAN session, you can describe the session and add interfaces and VLANs as sources and destinations.

Examples

This example shows how to create a SPAN session:

switch# configure terminal 

switch(config)# monitor session 2 

switch(config)#

This example shows how to enter the monitor configuration mode for configuring SPAN session number 9 for analyzing traffic between ports:

switch(config)# monitor session 9 type local 

switch(config-monitor)# description A Local SPAN session 

switch(config-monitor)# source interface ethernet 1/1 

switch(config-monitor)# destination interface ethernet 1/2 

switch(config-monitor)# no shutdown 

This example shows how to configure any SPAN destination interfaces as Layer 2 SPAN monitor ports before activating the SPAN session:

switch(config)# interface ethernet 1/2 

switch(config-if)# switchport 

switch(config-if)# switchport monitor 

switch(config-if)# no shutdown 

This example shows how to configure a typical SPAN destination trunk interface:

switch(config)# interface Ethernet1/2 

switch(config-if)# switchport 

switch(config-if)# switchport mode trunk 

switch(config-if)# switchport monitor 

switch(config-if)# switchport trunk allowed vlan 10-12 

switch(config-if)# no shutdown 

This example shows how to create an ERSPAN session:

switch# configure terminal 

switch(config)# monitor session 1 type erspan-source

switch(config-erspan-src)#

Related Commands

Command	Description
description (SPAN, ERSPAN)	Adds a description to identify the SPAN session.
destination (ERSPAN)	Configures the destination IP port for an ERSPAN packet.
erspan-id (ERSPAN)	Sets the flow ID for an ERSPAN session.
ip dscp (ERSPAN)	Sets the DSCP value for an ERSPAN packet.
ip prec (ERSPAN)	Sets the IP precedence value for an ERSPAN packet.
ip ttl (ERSPAN)	Sets the time-to-live (TTL) value for an ERSPAN packet.
mtu (ERSPAN)	Sets the maximum transmission value (MTU) for ERSPAN packets.
show monitor session	Displays SPAN session configuration information.
source (SPAN, ERSPAN)	Adds a SPAN source port.

mtu

To configure the maximum transmission unit (MTU) truncation size for packets in the specified Ethernet Switched Port Analyzer (SPAN) session, use the mtu command. To remove the MTU truncation size configuration, use the no form of this command.

mtu mtu-size

no mtu

Syntax Description

mtu-size

MTU truncation size. The range is from 64 to 1500.

Command Default

Disabled

Command Modes

Monitor configuration (config-monitor)

Supported User Roles

network-admin
vdc-admin

Command History

Release	Modification
5.2(1)N1(1)	This command was introduced.

Usage Guidelines

MTU truncation and the SPAN rate limit cannot be enabled for the same SPAN session. If you configure both for one session, only the rate limit is allowed on F1 Series modules, and MTU truncation is disabled until you disable the rate limit configuration.

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Note MTU turncation is supported only on F1 Series modules and F2 Series modules.

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This command does not require a license.

Examples

This example shows how to configure the MTU truncation size for packets in the specified SPAN session:

switch# configure terminal

switch(config)# monitor session 5

switch(config-monitor)# mtu 128

switch(config-monitor)#

This example shows how to remove the MTU truncation size configuration for packets in the specified SPAN session:

switch# configure terminal

switch(config)# monitor session 5

switch(config-monitor)# no mtu

Related Commands

Command	Description
monitor session	Places you in the monitor configuration mode for configuring a SPAN session.
show monitor session	Displays the status of the SPAN session.