Cisco Catalyst 2960-X Command Reference

spanning-tree mst root
To designate the primary and secondary root switch and set the timer value for an instance, use the
spanning-tree mst root command in global configuration mode. To return to the default settings, use the no
form of this command.
spanning-tree mst instance root {primary| secondary}
no spanning-tree mst instance root
Syntax Description
Instance identification number. The range is 0 to
4094.
instance
Forces this switch to be the root switch.primary
Specifies this switch to act as the root switch, if the
primary root fail.
secondary
Command Default
None
Command Modes
Global configuration (config)
Command History
ModificationRelease
This command was introduced.Cisco IOS 15.0(2)EX
Usage Guidelines
Use this command only on backbone switches. You can enter instance-id as a single instance or a range of
instances, for example, 0-3,5,7-9.
When you enter the spanning-tree mst instance-id root command, the software tries to set a high enough
priority to make this switch the root of the spanning-tree instance. Because of the extended system ID support,
the switch sets the switch priority for the instance to 24576 if this value will cause this switch to become the
root for the specified instance. If any root switch for the specified instance has a switch priority lower than
24576, the switch sets its own priority to 4096 less than the lowest switch priority. (4096 is the value of the
least-significant bit of a 4-bit switch priority value.)
When you enter the spanning-tree mstinstance-id root secondary command, because of support for the
extended system ID, the software changes the switch priority from the default value (32768) to 28672. If the
root switch fails, this switch becomes the next root switch (if the other switches in the network use the default
switch priority of 32768 and are therefore unlikely to become the root switch).
Catalyst 2960-X Switch Layer 2 Command Reference, Cisco IOS Release 15.0(2)EX
102 OL-29043 -01
Layer 2 Commands
spanning-tree mst root

Cisco Catalyst 2960-X Specifications

General

Console port	RJ-45
USB 2.0 ports quantity	2
SFP module slots quantity	4
Installed SFP modules quantity	-
Gigabit Ethernet (copper) ports quantity	48
Basic switching RJ-45 Ethernet ports type	Gigabit Ethernet (10/100/1000)
Power source	AC
Input current	5 A
AC input voltage	100 - 240 V
Power consumption (typical)	60.9 W
Number of power supply units	1
Redundant power supply (RPS) support	Yes
Operating altitude	0 - 3000 m
Non-operating altitude	0 - 4000 m
Storage temperature (T-T)	-25 - 70 °C
Operating temperature (T-T)	-5 - 40 °C
Operating relative humidity (H-H)	10 - 95 %
Switching protocols	UDP, TCP, RADIUS/TACACS+
Number of VLANs	1023
Networking standards	IEEE 802.1ab, IEEE 802.1D, IEEE 802.1p, IEEE 802.1Q, IEEE 802.1s, IEEE 802.1w, IEEE 802.1x, IEEE 802.3, IEEE 802.3ab, IEEE 802.3ad, IEEE 802.3ae, IEEE 802.3af, IEEE 802.3ah, IEEE 802.3at, IEEE 802.3az, IEEE 802.3u, IEEE 802.3x, IEEE 802.3z
Throughput	107.1 Mpps
Jumbo frames	9216
Number of queues	8
MAC address table	16000 entries
Number of static routes	1000
DHCP features	DHCP server
Authentication	MAC-based authentication, Port-based authentication
Security algorithms	802.1x RADIUS, SNMP, SSH
Access Control List (ACL) rules	3
Switch type	Managed
Switch layer	L2/L3
Safety	UL 60950-1, CAN/CSA-C22.2 No. 60950-1, EN 60950-1, IEC 60950-1, AS/NZS 60950-1
Form factor	1U
Product color	Black
Total Power over Ethernet (PoE) budget	370 W
Power over Ethernet (PoE) ports quantity	24
Power over Ethernet plus (PoE+) ports quantity	12
Memory type	DRAM
Noise level	39 dB
Flash memory	128 MB
Internal memory	512 MB
Processor frequency	600 MHz
Mean time between failures (MTBF)	276870 h

Weight and Dimensions

Depth	368 mm
Width	445 mm
Height	45 mm
Weight	5800 g