Layer 3 Switching Software Feature and Configuration Guide, 12.0(4a)WX5(11a)
Layer 3 Switching Command Reference
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Table of Contents

Layer 3 Switching Command Reference
 Port Snooping Commands
 QoS Commands

Layer 3 Switching Command Reference

This appendix provides a command reference for those Cisco IOS commands—or aspects of the commands—that are unique to Layer 3 switching.

Port Snooping Commands

Port snooping lets you transparently mirror traffic from one source port to a destination port. The following commands let you set up and monitor snooping.

snoop

To set up port-based traffic mirroring, or snooping, use the snoop command. To disable snooping, use the no form of this command.

snoop interface source_port direction snoop_direction
no snoop interface source_port
Syntax Description

source_port

Number of the port being monitored.

direction

Direction of traffic on the source port or ports that is monitored: receive, transmit, or both.

Default

Snooping is disabled on all interfaces.

Command Mode

Interface configuration

Usage Guidelines

The snooping destination port can be any port in the system, except for the source port, the Ethernet management port on the route processor, or any port configured for Fast EtherChannel.

The snooping source port can be any port on an interface module.

Example

The following example shows how to set up bidirectional port snooping using the snoop interface configuration command. In this example, the destination port is 12/0/15 and the source port is 0/0/1.

8500CSR# configure terminal
8500CSR(config)# interface fa 12/0/15
8500CSR(config-if)# shutdown
8500CSR(config-if)# snoop interface fa 0/0/1 direction both
8500CSR(config-if)# no shutdown
Related Command

show snoop

show snoop

To display the current snooping sessions, use the show snoop command.

show snoop [interface destination_port]
Syntax Description

destination_port

Number of the snooping interface.

Command Mode

Privileged EXEC

Example

The following example shows output from the show snoop command.

8500CSR# show snoop
Snoop Test Port Name: FastEthernet1/0/4 (interface status=SNOOPING)
Snoop option: (configured=enabled)(actual=enabled)
Snoop direction: (configured=receive)(actual=receive)
Monitored Port Name:
(configured=FastEthernet1/0/3)(actual=FastEthernet1/0/3)
Related Command

show snoop-vc

show snoop-vc

To display the virtual circuits being used by the snooping feature, use the show snoop-vc command.

show snoop-vc [interface destination_port]
Syntax Description

destination_port

Snoop monitoring port.

Command Mode

Privileged EXEC

Example

The following example shows output from the show snoop-vc command.

8500CSR# show snoop-vc
Snooping Snooped
Interface VPI VCI Type X-Interface X-VPI X-VCI Dir Status
FastEthernet1/0/4 4 223 PVC FastEthernet1/0/3 0
35 RX UP
FastEthernet1/0/4 4 224 PVC FastEthernet1/0/3 0
36 RX UP
FastEthernet1/0/4 8 223 PVC FastEthernet1/0/3 0
57 RX UP
FastEthernet1/0/4 8 224 PVC FastEthernet1/0/3 0
58 RX UP
FastEthernet1/0/4 8 225 PVC FastEthernet1/0/3 0
59 RX UP
.........
Related Command

show snoop

QoS Commands

qos switching

To enable Quality of Service (QoS) mapping on the device, use the qos switching command. To disable it, use the no form of this command.

qos switching
no qos switching
Syntax Description

This command has no keywords or arguments.

Default

QoS mapping is enabled.

Command Mode

Device configuration

Example

The following example shows how to enable QoS mapping using the qos switching configuration command.

8500CSR# qos switching
Related Command

qos mapping-precedence

qos mapping-precedence

To configure QoS mapping at the system or interface level, use the qos mapping-precedence command. To set the QoS precedence back to the default value, use the no form of this command.

qos mapping [source source_int] [destination dest_int] precedence value wrr-weight weight
no qos mapping precedence
Syntax Description

source_int

Source interface from which you want to define a traffic precedence; optional.

dest_int

Destination interface to which you want to define a traffic precedence; optional.

value

Precedence value derived from the higher two bits of the IP precedence field. Valid values are 0 to 3 inclusive.

weight

WRR-scheduling weight. Valid values are 1 to 15 inclusive. This specifies the weight assigned to traffic with the given precedence value.

Default

The default WRR-weight for a precedence value n is 2 ^ n.

Command Mode

Device configuration

Usage Guideline

When a precedence value n is specified, it implicitly assigns the same WRR-weight to the precedence n + 1.

Example

The following example shows how to set the system-level QoS mapping using the qos mapping-precedence configuration command.

8500CSR(config)# qos mapping precedence 0 wrr-weight 4
Related Command

qos switching

show qos switching

To show whether QoS mapping is enabled on the device, use the show qos switching command.

show qos switching
Syntax Description

This command has no keywords or arguments.

Command Mode

Privileged EXEC

Example

The following example shows how to display whether QoS mapping is enabled using the show qos switching command.

8500CSR# show qos switching
QoS Based IP Switching enabled
Related Command

show qos mapping

show qos mapping

To show the QoS mapping in effect at the system or interface level, use the show qos mapping command.

show qos mapping [source source_int] [destination dest_int]
Syntax Description

source_int

Source interface from which you want to display QoS mapping; optional.

dest_int

Destination interface to which you want to display QoS mapping; optional.

Command Mode

Privileged EXEC

Example

The following example shows how to display the system-level QoS mapping using the show qos mapping command.

8500CSR# show qos mapping
Precedence WRR-Weight
0 1
1 2
2 4
3 8
Related Command

show qos switching