Cisco Catalyst 4500 Series, Software Configuration Manual

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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
For example, before setting the per-interface MTU for interface gi1/1, you enter the system mtu 1550 command to change the
MTU for gi1/1 to 1550 bytes. You enter the per-interface mtu command to change the MTU for gi1/1 to 9198 bytes. If you
change the baby giant MTU to 1540 bytes with the command system mtu 1540 , the MTU for gi1/1 remains unchanged at 9198
bytes.
Configuring the Port Debounce Timer
Note
You can only configure port debounce on 10-Gigabit Ethernet ports.
The port debounce timer suppresses notification of short link-down events. Link-down events that are shorter than the port
debounce timer are not notified to Layer 2 or Layer 3 protocols, decreasing traffic loss due to network reconfiguration. You
can configure the port debounce timer separately on each LAN port.
Caution Enabling the port debounce timer causes a delay in link down detections, resulting in loss of traffic
during the debouncing period. This situation might affect the convergence and reconvergence of some
Layer 2 and Layer 3 protocols.
To configure the debounce timer on a port, perform this task:
Note The default time is 10ms for E-series supervisor engines and line cards.
When configuring the debounce timer on a port, you can increase the port debounce timer value between 10 milliseconds and
5000 milliseconds on the 10-Gigabit Ethernet ports.
This example shows how to enable the port debounce timer on 10-Gigabit Ethernet port 2/1 and to accept the default value (10
ms):
Switch# config terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# interface tenGigabitEthernet 2/1
Switch(config-if)# link debounce
Warning: Enabling debounce feature causes link down detection to be delayed
Switch(config-if)# exit
This example shows how to enable the port debounce timer of 5000 ms on 10-Gigabit Ethernet port 2/2 and to verify the setting:
Switch# config terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# interface tenGigabitEthernet 2/2
Switch(config-if)# link debounce time 5000
Command Purpose
Step 1
Switch(config)# interface tengigabitethernet
slot/port
Selects the port to configure.
Step 2
Switch(config-if)# link debounce [time
debounce_time]
Configures the debounce timer.
By default, debounce is disabled.
Switch(config-if)# no link debounce
Reverts to the default setting.
Step 3
Switch#
show interfaces debounce
Verifies the configuration.