TP-Link TL-SG5412F User Manual

Figure 7-1 Basic STP diagram
 STP Timers
Hello Time:
Hello Time ranges from 1 to 10 seconds. It specifies the interval to send BPDU packets. It is used
to test the links.
Max. Age:
Max. Age ranges from 6 to 40 seconds. It specifies the maximum time the switch can wait without
receiving a BPDU before attempting to reconfigure.
Forward Delay:
Forward Delay ranges from 4 to 30 seconds. It specifies the time for the port to transit its state
after the network topology is changed.
When the STP regeneration caused by network malfunction occurs, the STP structure will get
some corresponding change. However, as the new configuration BPDUs cannot be spread in the
whole network at once, the temporal loop will occur if the port transits its state immediately.
Therefore, STP adopts a state transit mechanism, that is, the new root port and the designated
port begins to forward data after twice forward delay, which ensures the new configuration BPDUs
are spread in the whole network.
 BPDU Comparing Principle in STP mode
Assuming two BPDUs: BPDU X and BPDU Y
If the root bridge ID of X is smaller than that of Y, X is superior to Y.
If the root bridge ID of X equals that of Y, but the root path cost of X is smaller than that of Y, X is
superior to Y.
If the root bridge ID and the root path cost of X equal those of Y, but the bridge ID of X is smaller
than that of Y, X is superior to Y.
If the root bridge ID, the root path cost and bridge ID of X equal those of Y, but the port ID of X is
smaller than that of Y, X is superior to Y.
 STP Generation
 In the beginning
In the beginning, each switch regards itself as the root, and generates a configuration BPDU for
each port on it as a root, with the root path cost being 0, the ID of the designated bridge being that
of the switch, and the designated port being itself.
 Comparing BPDUs
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TP-Link TL-SG5412F Specifications

General

MAC address table	8000 entries
Jumbo frames support	Yes
Maximum data transfer rate	1 Gbit/s
Supported data transfer rates	10, 100, 1000Mbps
Fan	0
Wi-Fi	No
Diagnostics	VCT
Management platform	SNMP, RMON, WEB/CLI/Telnet
Authentication method	802.1X, Radius
Packet transfer speed	17.99Mpps
Connectivity technology	Wired
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 802.3i, IEEE 802.3u, IEEE 802.3x, IEEE 802.3z
Ethernet LAN data rates	10, 100, 1000 Mbit/s
Copper ethernet cabling technology	1000BASE-T, 100BASE-TX, 10BASE-T
DHCP features	DHCP client
Security algorithms	SSH, SSL/TLS
Switch type	Managed
Switch layer	L2
Console port	RJ-45
Fiber optic connector	SFP
SFP/SFP+ slots quantity	12
Basic switching RJ-45 Ethernet ports quantity	4
Fiber ethernet cabling technology	100BASE-FX
AC input voltage	100 - 240 V
AC input frequency	50 - 60 Hz
Stackable	-
Form factor	1U
Certification	CE, FCC
Product color	Black
Compatible operating systems	Windows 98SE, NT, 2000, XP, Vista, Windows 7\\r MAC OS\\r NetWare\\r UNIX\\r Linux
Storage temperature (T-T)	-40 - 70 °C
Operating temperature (T-T)	0 - 40 °C
Storage relative humidity (H-H)	5 - 90 %
Operating relative humidity (H-H)	10 - 90 %

Weight and Dimensions

Depth	260 mm
Width	440 mm
Height	44 mm