6-15
Catalyst 6500 Series Switch Cisco IOS Software Configuration Guide—Release 12.1 E
78-14099-04
Chapter 6 Configuring Interfaces
Configuring Optional Interface Features
When configuring flow control, note the following syntax information:
• 10-Gigabit Ethernet ports are permanently configured to respond to pause frames.
• When the configuration of the remote ports is unknown, use the receive desired keywords to
configure a Gigabit Ethernet port to respond to received pause frames.
• Use the receive on keywords to configure a Gigabit Ethernet port to respond to received pause
frames.
• Use the receive off keywords to configure a Gigabit Ethernet port to ignore received pause frames.
• When configuring transmission of pause frames, note the following information:
–
When the configuration of the remote ports is unknown, use the send desired keywords to
configure a port to send pause frames.
–
Use the send on keywords to configure a port to send pause frames.
–
Use the send off keywords to configure a port not to send pause frames.
This example shows how to turn on receive flow control and how to verify the flow-control
configuration:
Router# configure terminal
Router(config)# interface gigabitethernet 1/2
Router(config-if)# flowcontrol receive on
Router(config-if)# end
Router# show interfaces flowcontrol
Interface Send Receive
Gi1/1 Desired OFF
Gi1/2 Desired ON
Fa5/1 Not capable OFF
<output truncated>
Configuring the Port Debounce Timer
The port debounce timer delays notification of a link change, which can decrease traffic loss due to
network reconfiguration. Release 12.1(13)E and later releases support the port debounce timer on all
LAN ports. You can configure the port debounce timer separately on each LAN port.
Caution Enabling the port debounce timer causes link up and link down detections to be delayed, 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.
Table 6-2 lists the time delay that occurs before notification of a link change.
Table 6-2 Port Debounce Timer Delay Time
Port Type Debounce Timer Disabled Debounce Timer Enabled
10BASE-FL ports 300 milliseconds 3100 milliseconds
10/100BASE-TX ports 300 milliseconds 3100 milliseconds
100BASE-FX ports 300 milliseconds 3100 milliseconds
10/100/1000BASE-TX ports 300 milliseconds 3100 milliseconds
1000BASE-TX ports 300 milliseconds 3100 milliseconds