Cisco Catalyst 2950 User Manual

15-19
Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
78-11380-12
Chapter 15 Configuring Optional Spanning-Tree Features
Configuring Optional Spanning-Tree Features
Beginning in privileged EXEC mode, follow these steps to enable CSUF. This procedure is optional.
To disable CSUF on an interface, use the no spanning-tree stack-port interface configuration
command. To disable UplinkFast on the switch and all its VLANs, use the no spanning-tree uplinkfast
global configuration command.
Enabling BackboneFast
You can enable BackboneFast to detect indirect link failures and to start the spanning-tree
reconfiguration sooner.
Note If you use BackboneFast, you must enable it on all switches in the network. BackboneFast is not
supported on Token Ring VLANs. This feature is supported for use with third-party switches.
You can enable the BackboneFast feature for rapid PVST+ or for the MSTP, but the feature remains
disabled (inactive) until you change the spanning-tree mode to PVST+.
Command Purpose
Step 1
configure terminal Enter global configuration mode.
Step 2
spanning-tree uplinkfast [max-update-rate
pkts-per-second]
Enable UplinkFast on the switch.
(Optional) For max-update-rate pkts-per-second, specify the
number of packets per second at which update packets are sent. The
range is 0 to 65535; the default is 150 packets per second.
Step 3
interface interface-id Specify the GBIC module interface on which to enable CSUF, and
enter interface configuration mode.
Step 4
spanning-tree stack-port Enable CSUF on only one stack-port GBIC interface.
The stack port connects to the GigaStack GBIC module multidrop
backbone. If you try to enable CSUF on a Fast Ethernet or a
Gigabit-capable Ethernet port, you receive an error message.
If CSUF is already enabled on an interface and you try to enable it
on another interface, you receive an error message. You must disable
CSUF on the first interface before enabling it on a new interface.
Use this command only on access switches.
Step 5
end Return to privileged EXEC mode.
Step 6
show running-config Verify your entries.
Step 7
copy running-config startup-config (Optional) Save your entries in the configuration file.

Cisco Catalyst 2950 Specifications

General

Forwarding Bandwidth	8.8 Gbps
Switching Capacity	13.6 Gbps
Forwarding Rate	6.6 Mpps
Weight	3.6 kg
RAM	16 MB
Flash Memory	8 MB
Operating Humidity	10% to 85% non-condensing
Uplink Ports	2 x 10/100/1000Base-T
Dimensions	4.4 cm x 44.5 cm x 24.2 cm
Remote Management Protocol	SNMP, Telnet, HTTP
Features	Quality of Service (QoS), VLAN support
Compliant Standards	IEEE 802.3, IEEE 802.3u, IEEE 802.1D, IEEE 802.1Q, IEEE 802.1p
Status Indicators	system
Operating Temperature	0 to 45°C
Ports	24 x 10/100 Ethernet ports
MAC Address Table Size	8, 192 entries
Power Supply	Internal 100-240V AC, 50-60Hz