Linksys LGS326P User Manual

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Chapter 7 - Spanning Tree Management
Spanning Tree Protocol protects a Layer 2 Broadcast domain from Broadcast storms by
selectively setting links to standby mode to prevent loops. In standby mode, these links
temporarily stop transferring user data. After the topology changes so that the data transfer is
made possible, the links are automatically reactivated.
Loops occur when alternate routes exist between hosts. Loops in an extended network can cause
switches to forward traffic indefinitely, resulting in increased traffic load and reduced network
efficiency.
STP provides a tree topology for any arrangement of switches and interconnecting links, by
creating a unique path between end stations on a network, and thereby eliminating loops.
Spanning Tree Protocol versions:
•
Classic STP – Provides a single path between any two end stations, avoiding and
eliminating loops.
•
Rapid STP (RSTP) – Detects network topologies to provide faster convergence of the
spanning tree. This is most effective when the network topology is naturally tree-
structured, and therefore faster convergence might be possible. RSTP is enabled by
default.
•
Multiple STP (MSTP) – Classic STP and Rapid STP detect Layer 2 loops, and attempt to
mitigate them by preventing the involved port from transmitting traffic. Since loops exist
on a per-Layer 2-domain basis, there can be a loop in VLAN A and no loop in VLAN B. If
both VLANs are on Port X, Classic STP and Rapid STP will mitigate the loop by stopping
traffic on the entire port, including VLAN B traffic.
MSTP solves this problem by enabling several STP instances, so that it is possible to
detect and mitigate loops separately in each instance. By associating instances to VLANs,
each instance is associated with the Layer 2 domain on which it performs loop detection
and mitigation. This enables a port to be stopped in one instance, such as traffic from
VLAN A that is causing a loop, while traffic can remain active in another domain where no
loop was seen, such as on VLAN B.

Linksys LGS326P Specifications

General

Switch type	Managed
Switch layer	-
Quality of Service (QoS) support	Yes
Combo SFP ports quantity	2
Installed SFP+ modules quantity	0
Gigabit Ethernet (copper) ports quantity	26
Basic switching RJ-45 Ethernet ports type	Gigabit Ethernet (10/100/1000)
Basic switching RJ-45 Ethernet ports quantity	24
10G support	No
Number of VLANs	128
Networking standards	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 802.3af, IEEE 802.3az, IEEE 802.3u, IEEE 802.3x, IEEE 802.3z
Virtual LAN features	Tagged VLAN
Copper ethernet cabling technology	1000BASE-T, 100BASE-T, 10BASE-T
DHCP features	DHCP client
Security algorithms	802.1x RADIUS
Throughput	38.69 Mpps
Jumbo frames	9000
MAC address table	8000 entries
Product color	Black, Blue
LED indicators	Activity, Link, PoE, System
Number of fans	2 fan(s)
Memory type	DRAM
Internal memory	128 MB
Input current	3.5 A
AC input voltage	100 - 240 V
AC input frequency	50 - 60 Hz
Power consumption (typical)	28.58 W
Total Power over Ethernet (PoE) budget	192 W
Storage temperature (T-T)	-40 - 70 °C
Operating temperature (T-T)	0 - 50 °C
Operating relative humidity (H-H)	10 - 90 %

Weight and Dimensions

Depth	200 mm
Width	440 mm
Height	44 mm
Weight	3096 g