Cisco WS-C2980G-A Software Guide - Page 171

Configuring UplinkFast, Enabling UplinkFast

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Chapter 8 Configuring Spanning Tree PortFast, BPDU Guard, BPDU Filter, UplinkFast, BackboneFast, and Loop Guard Configuring UplinkFast Configuring UplinkFast The following sections describe how to configure the UplinkFast feature on the switch. Enabling UplinkFast When you enable UplinkFast on the switch, UplinkFast processing is enabled and the spanning tree bridge priority for all VLANs is set to 49,152, making it unlikely that the switch will become the root switch. In addition, the spanning tree port cost and port-VLAN cost of all ports on the switch is increased by 3000. The station_update_rate value in the UplinkFast command represents the number of dummy multicast packets that are transmitted per 100 ms (the default is 15 packets per 100 ms) in the event of a direct link failure. Enter the all-protocols on keywords on switches that have UplinkFast enabled but do not have protocol filtering enabled, and that are connected to upstream switches in the network that have protocol filtering enabled. The all-protocols on keywords cause the switch to generate multicasts for each protocol-filtering group. On switches with both UplinkFast and protocol filtering enabled, or if no other switches have protocol filtering enabled, you do not need to use the all-protocols on keywords. Note When you enable UplinkFast, it affects all VLANs on the switch. You cannot configure UplinkFast on a per-VLAN basis. To enable UplinkFast, perform this task in privileged mode: Task Step 1 Enable UplinkFast on the switch. Step 2 Verify that UplinkFast is enabled. Command set spantree uplinkfast enable [rate station_update_rate] [all-protocols {off | on}] show spantree uplinkfast [vlans] This example shows how to enable UplinkFast with a station-update rate of 40 packets per 100 ms and how to verify that UplinkFast is enabled: Console> (enable) set spantree uplinkfast enable rate 40 VLANs 1-1005 bridge priority set to 49152. The port cost and portvlancost of all ports set to above 3000. Station update rate set to 40 packets/100ms. uplinkfast all-protocols field set to off. uplinkfast enabled for bridge. Console> (enable) show spantree uplinkfast Station update rate set to 40 packets/100ms. uplinkfast all-protocols field set to off. VLAN port list 78-15486-01 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 8-15

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8-15
Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide
Release 8.1
78-15486-01
Chapter 8
Configuring Spanning Tree PortFast, BPDU Guard, BPDU Filter, UplinkFast, BackboneFast, and Loop Guard
Configuring UplinkFast
Configuring UplinkFast
The following sections describe how to configure the UplinkFast feature on the switch.
Enabling UplinkFast
When you enable UplinkFast on the switch, UplinkFast processing is enabled and the spanning tree
bridge priority for all VLANs is set to 49,152, making it unlikely that the switch will become the root
switch. In addition, the spanning tree port cost and port-VLAN cost of all ports on the switch is increased
by 3000.
The
station_update_rate
value in the UplinkFast command represents the number of dummy multicast
packets that are transmitted per 100 ms (the default is 15 packets per 100 ms) in the event of a direct link
failure.
Enter the
all-protocols on
keywords on switches that have UplinkFast enabled but do not have protocol
filtering enabled, and that are connected to upstream switches in the network that have protocol filtering
enabled. The
all-protocols on
keywords cause the switch to generate multicasts for each
protocol-filtering group.
On switches with both UplinkFast and protocol filtering enabled, or if no other switches have protocol
filtering enabled, you do not need to use the
all-protocols on
keywords.
Note
When you enable UplinkFast, it affects all VLANs on the switch. You cannot configure UplinkFast on a
per-VLAN basis.
To enable UplinkFast, perform this task in privileged mode:
This example shows how to enable UplinkFast with a station-update rate of 40 packets per 100 ms and
how to verify that UplinkFast is enabled:
Console> (enable)
set spantree uplinkfast enable rate 40
VLANs 1-1005 bridge priority set to 49152.
The port cost and portvlancost of all ports set to above 3000.
Station update rate set to 40 packets/100ms.
uplinkfast all-protocols field set to off.
uplinkfast enabled for bridge.
Console> (enable)
show spantree uplinkfast
Station update rate set to 40 packets/100ms.
uplinkfast all-protocols field set to off.
VLAN
port list
-----------------------------------------------
Task
Command
Step 1
Enable UplinkFast on the switch.
set spantree uplinkfast enable
[
rate
station_update_rate
]
[
all-protocols
{
off
|
on
}]
Step 2
Verify that UplinkFast is enabled.
show spantree uplinkfast
[
vlans
]