Planet IGS-20040MT User Manual

User’s Manual of IGS-20040MT
4.7 Spanning Tree Protocol
4.7.1 Theory
The Spanning Tree protocol can be used to detect and disable network loops, and to provide backup links between switches,
bridges or routers. This allows the switch to interact with other bridging devices in your network to ensure that only one route
exists between any two stations on the network, and provide backup links which automatically take over when a primary link
goes down. The spanning tree algorithms supported by this switch include these versions:
 STP – Spanning Tree Protocol (IEEE 802.1D)
 RSTP – Rapid Spanning Tree Protocol (IEEE 802.1w)
 MSTP – Multiple Spanning Tree Protocol (IEEE 802.1s)
The IEEE 802.1D Spanning Tree Protocol and IEEE 802.1w Rapid Spanning Tree Protocol allow for the blocking of links
between switches that form loops within the network. When multiple links between switches are detected, a primary link is
established. Duplicated links are blocked from use and become standby links. The protocol allows for the duplicate links to be
used in the event of a failure of the primary link. Once the Spanning Tree Protocol is configured and enabled, primary links are
established and duplicated links are blocked automatically. The reactivation of the blocked links (at the time of a primary link
failure) is also accomplished automatically without operator intervention.
This automatic network reconfiguration provides maximum uptime to network users. However, the concepts of the Spanning
Tree Algorithm and protocol are a complicated and complex subject and must be fully researched and understood. It is possible
to cause serious degradation of the performance of the network if the Spanning Tree is incorrectly configured. Please read the
following before making any changes from the default values.
The Switch STP performs the following functions:
 Creates a single spanning tree from any combination of switching or bridging elements.
 Creates multiple spanning trees – from any combination of ports contained within a single switch, in user specified
groups.
 Automatically reconfigures the spanning tree to compensate for the failure, addition, or removal of any element in
the tree.
 Reconfigures the spanning tree without operator intervention.
Bridge Protocol Data Units
For STP to arrive at a stable network topology, the following information is used:
 The unique switch identifier
 The path cost to the root associated with each switch port
 The port identifier
STP communicates between switches on the network using Bridge Protocol Data Units (BPDUs). Each BPDU contains the
following information:
 The unique identifier of the switch that the transmitting switch currently believes is the root switch
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Planet IGS-20040MT Specifications

General

Switch type	Managed
Switch layer	L2+
Traffic classification	Yes
Console port	RJ-45
Fiber optic connector	MiniGBIC
SFP module slots quantity	4
Installed SFP modules quantity	0
Basic switching RJ-45 Ethernet ports type	Gigabit Ethernet (10/100/1000)
Basic switching RJ-45 Ethernet ports quantity	16
10G support	No
Number of VLANs	4095
Networking standards	IEEE 1588v2, IEEE 802.1D, IEEE 802.1Q, IEEE 802.1ab, IEEE 802.1ad, IEEE 802.1ag, IEEE 802.1p, IEEE 802.1s, IEEE 802.1w, IEEE 802.1x, IEEE 802.3, IEEE 802.3ab, IEEE 802.3ad, IEEE 802.3ah, IEEE 802.3u, IEEE 802.3x, IEEE 802.3z
Virtual LAN features	Stacked VLAN, Private VLAN, Tagged VLAN, Protocol-based VLAN
Copper ethernet cabling technology	10BASE-T, 100BASE-TX, 1000BASE-T
Stackable	-
Certification	FCC, CE
Product color	Blue, White
Housing material	Aluminum
International Protection (IP) code	IP30
Fiber ethernet cabling technology	100BASE-FX, 1000BASE‑BX, 1000BASE‑LX, 1000BASE‑SX
Throughput	29.7 Mpps
Jumbo frames	9216
MAC address table	8000 entries
Number of IP interfaces	8
Power consumption (max)	17 W
Power consumption (typical)	8 W
Heat dissipation	27 BTU/h
Storage temperature (T-T)	-40 - 85 °C
Operating temperature (T-T)	-40 - 75 °C
Operating relative humidity (H-H)	5 - 95 %
Supported network protocols	IPv4 / IPv6
Authentication	MAC-based authentication, Port-based authentication
Security algorithms	802.1x RADIUS, SSH, SSL/TLS
Number of multicast groups filtered	255
Harmonized System (HS) code	85176990

Weight and Dimensions

Depth	107.3 mm
Width	76.8 mm
Height	152 mm
Weight	1043 g