Cisco Systems 3560-X, 3750-X Configuring Protected Ports

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Catalyst 3750-X and 3560-X Switch Software Configuration Guide

OL-21521-01

Chapter 28 Configuring Port-Based Traffic Control

Configuring Protected Ports

This example shows how to enable the small-frame arrival-rate feature, configure the port recovery time,

and configure the threshold for error disabling a port:

Switch# configure terminal

Switch# errdisable detect cause small-frame

Switch# errdisable recovery cause small-frame

Switch(config)# interface gigabitethernet1/0/1

Switch(config-if)# small-frame violation rate 10000

Switch(config-if)# end

Configuring Protected Ports

Some applications require that no traffic be forwarded at Layer 2 between ports on the same switch so

that one neighbor does not see the traffic generated by another neighbor. In such an environment, the use

of protected ports ensures that there is no exchange of unicast, broadcast, or multicast traffic between

these ports on the switch.

Protected ports have these features:

• A protected port does not forward any traffic (unicast, multicast, or broadcast) to any other port that

is also a protected port. Data traffic cannot be forwarded between protected ports at Layer 2; only

control traffic, such as PIM packets, is forwarded because these packets are processed by the CPU

and forwarded in software. All data traffic passing between protected ports must be forwarded

through a Layer 3 device.

• Forwarding behavior between a protected port and a nonprotected port proceeds as usual.

Because a switch stack represents a single logical switch, Layer 2 traffic is not forwarded between any

protected ports in the switch stack, whether they are on the same or different switches in the stack.

• Default Protected Port Configuration, page 28-6

• Protected Port Configuration Guidelines, page 28-7

• Configuring a Protected Port, page 28-7

The default is to have no protected ports defined.

Step 5 interface interface-id Enter interface configuration mode, and specify the interface to be

configured.

Step 6 small violation-rate pps Configure the threshold rate for the interface to drop incoming

packets and error disable the port. The range is 1 to 10,000 packets

per second (pps)

Step 7 end Return to privileged EXEC mode.

Step 8 show interfaces interface-id Verify the configuration.

Step 9 copy running-config startup-config (Optional) Save your entries in the configuration file.

Command Purpose