9-14
Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX
OL-4266-08
Chapter 9 Configuring Interfaces
Configuring Optional Interface Features
When configuring flow control, note the following information:
•
Because auto negotiation does not work on 10 Gigbit Ethernet fiber optic ports, they respond to
pause frames by default. On 10 Gigbit Ethernet fiber optic ports, the flow-control operational mode
is always the same as administrative mode.
•
You cannot configure how WS-X6502-10GE 10-Gigabit Ethernet ports respond to pause frames.
WS-X6502-10GE 10-Gigabit Ethernet ports are permanently configured to respond to pause frames.
•
When configuring how a port responds to pause frames, note the following information:
–
For a Gigabit Ethernet port, when the configuration of a remote port is unknown, you can use
the
receive desired
keywords to configure the Gigabit Ethernet port to respond to received
pause frames. (Supported only on Gigabit Ethernet ports.)
–
Use the
receive on
keywords to configure a port to respond to received pause frames.
–
Use the
receive off
keywords to configure a port to ignore received pause frames.
•
When configuring transmission of pause frames on a port, note the following information:
–
For a Gigabit Ethernet port, when the configuration of the remote ports is unknown, you can use
the
send desired
keywords to configure the Gigabit Ethernet port to send pause frames.
(Supported only on Gigabit Ethernet ports.)
–
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. The delay in notification allows a quick port status change and recovery to
occur without triggering any of the STP topology changes that are necessary when a port goes down.
You can configure the port debounce timer separately on each LAN port.
Caution
Enabling the port debounce timer causes 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.
