Cisco Catalyst 2960-X User Manual

How Traffic Activity is Measured
Storm control uses one of these methods to measure traffic activity:
•
Bandwidth as a percentage of the total available bandwidth of the port that can be used by the broadcast,
multicast, or unicast traffic
•
Traffic rate in packets per second at which broadcast, multicast, or unicast packets are received
•
Traffic rate in bits per second at which broadcast, multicast, or unicast packets are received
•
Traffic rate in packets per second and for small frames. This feature is enabled globally. The threshold
for small frames is configured for each interface.
With each method, the port blocks traffic when the rising threshold is reached. The port remains blocked until
the traffic rate drops below the falling threshold (if one is specified) and then resumes normal forwarding. If
the falling suppression level is not specified, the switch blocks all traffic until the traffic rate drops below the
rising suppression level. In general, the higher the level, the less effective the protection against broadcast
storms.
When the storm control threshold for multicast traffic is reached, all multicast traffic except control traffic,
such as bridge protocol data unit (BDPU) and Cisco Discovery Protocol (CDP) frames, are blocked.
However, the switch does not differentiate between routing updates, such as OSPF, and regular multicast
data traffic, so both types of traffic are blocked.
Note
Traffic Patterns
This example shows broadcast traffic patterns on an interface over a given period of time.
Figure 28: Broadcast Storm Control Example
Broadcast traffic being forwarded exceeded the configured threshold between time intervals T1 and T2 and
between T4 and T5. When the amount of specified traffic exceeds the threshold, all traffic of that kind is
dropped for the next time period. Therefore, broadcast traffic is blocked during the intervals following T2
Catalyst 2960-X Switch Security Configuration Guide, Cisco IOS Release 15.0(2)EX
OL-29048-01 391
Configuring Port-Based Traffic Control
How Traffic Activity is Measured

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