Cisco 4006 - Catalyst Switch, Руководство по настройке, Страница: 64 / 614

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Catalyst 4500 Series, Catalyst 2948G, Catalyst 2948G-GE-TX, and Catalyst 2980G Switches Software Configuration Guide—Release 8.2GLX
78-15908-01
Chapter 4 Configuring Ethernet and Fast Ethernet Switching
Configuring Ethernet and Fast Ethernet Ports
Setting Ethernet and Fast Ethernet Port Debounce Timers
You can set the port debounce timer on a per-port basis for Ethernet, Fast Ethernet, and Gigabit Ethernet
ports. When you set the port debounce timer, the switch delays notifying the main processor of a link
down; this delay in notification can decrease traffic loss due to network reconfiguration.
Caution
Enabling the port debounce timer will delay link-up and link-down detections, resulting in loss of data
traffic during the debouncing period. This situation might delay the convergence and reconvergence of
various Layer 2 and Layer 3 protocols.
Table 4-2 lists the time delay that occurs before the switch notifies the main processor of a link down
before and after the switch enables the debounce timer.
To set the debounce timer on a port, perform this task in privileged mode:
This example shows how to enable the debounce timer for module 2 on port 1:
Console> (enable) set port debounce 2/1 enable
Debounce is enabled on port 2/1
Warning: Enabling port debounce causes Link Up/Down detections to be delayed.
It results in loss of data traffic during debouncing period, which might
affect the convergence/reconvergence of various Layer 2 and Layer 3 protocols.
Use with caution.
Console> (enable)
Table 4-2 Switch Notification Delays for the Port Debounce Timer
Delay Time
Port Type
With Debounce
Timer Disabled
With Debounce Timer Enabled
10/100 ports 0 ms 3.1 sec
100BASE-FX ports 0 ms 3.1 sec
10/100/1000BASE-TX ports 0 ms 3.1 sec
Gigabit TX ports 0 ms 3.1 sec
Fiber Gigabit ports 0 ms 3.1 sec
Note The delay time is the time
that the port is physically
down, and once the port is up,
the time the software needs to
complete autonegotiation.
Task Command
Step 1
Enable the debounce timer for a port. set port debounce
mod num/port num {enable | disable}
Step 2
Verify that the debounce timer of the port is
configured correctly. show port debounce [mod | mod_num/port_num]