C
HAPTER
4
| Configuring the Switch
Configuring the Spanning Tree Algorithm
– 76 –
This switch supports Rapid Spanning Tree Protocol (RSTP), but is backward
compatible with Spanning Tree Protocol (STP).
STP
- STP uses a distributed algorithm to select a bridging device (STP-
compliant switch, bridge or router) that serves as the root of the spanning
tree network. It selects a root port on each bridging device (except for the
root device) which incurs the lowest path cost when forwarding a packet
from that device to the root device. Then it selects a designated bridging
device from each LAN which incurs the lowest path cost when forwarding a
packet from that LAN to the root device. All ports connected to designated
bridging devices are assigned as designated ports. After determining the
lowest cost spanning tree, it enables all root ports and designated ports,
and disables all other ports. Network packets are therefore only forwarded
between root ports and designated ports, eliminating any possible network
loops.
Once a stable network topology has been established, all bridges listen for
Hello BPDUs (Bridge Protocol Data Units) transmitted from the Root Bridge.
If a bridge does not get a Hello BPDU after a predefined interval (Maximum
Age), the bridge assumes that the link to the Root Bridge is down. This
bridge will then initiate negotiations with other bridges to reconfigure the
network to reestablish a valid network topology.
RSTP
- RSTP is designed as a general replacement for the slower, legacy
STP. RSTP is also incorporated into MSTP (Multiple Spanning Tree Protocol).
RSTP achieves must faster reconfiguration (i.e., around 1 to 3 seconds,
compared to 30 seconds or more for STP) by reducing the number of state
changes before active ports start learning, predefining an alternate route
that can be used when a node or port fails, and retaining the forwarding
database for ports insensitive to changes in the tree structure when
reconfiguration occurs.
C
ONFIGURING
G
LOBAL
S
ETTINGS
FOR
STA
Use the RSTP System Configuration page to configure settings for STA
which apply globally to the switch.
P
ARAMETERS
The following parameters are displayed on the RSTP System Configuration
page:
◆
System Priority
– Bridge priority is used in selecting the root device,
root port, and designated port. The device with the highest priority
becomes the STA root device. However, if all devices have the same
x
Designated
Root
Designated
Port
Designated
Bridge
x
x
x
Root
Port
x
Содержание 8028L2
Страница 1: ...MANAGEMENT GUIDE TigerSwitchTM 10 100 1000 28 Port Gigabit Ethernet Switch SMC8028L2 ...
Страница 6: ...ABOUT THIS GUIDE 6 ...
Страница 22: ...FIGURES 22 ...
Страница 26: ...SECTION Getting Started 26 ...
Страница 46: ...CHAPTER 2 Initial Switch Configuration Managing System Files 46 ...
Страница 48: ...SECTION Web Configuration 48 ...
Страница 133: ...CHAPTER 4 Configuring the Switch Simple Network Management Protocol 133 Figure 34 SNMP System Configuration ...
Страница 144: ...CHAPTER 4 Configuring the Switch Configuring DHCP Relay and Option 82 Information 144 ...
Страница 184: ...CHAPTER 6 Performing Basic Diagnostics Running Cable Diagnostics 184 ...
Страница 238: ...CHAPTER 12 Port Commands 238 ...
Страница 244: ...CHAPTER 13 Link Aggregation Commands 244 ...
Страница 262: ...CHAPTER 15 RSTP Commands 262 ...
Страница 272: ...CHAPTER 16 IEEE 802 1X Commands 272 ...
Страница 282: ...CHAPTER 17 IGMP Commands 282 ...
Страница 290: ...CHAPTER 18 LLDP Commands 290 ...
Страница 296: ...CHAPTER 19 MAC Commands 296 ...
Страница 306: ...CHAPTER 21 PVLAN Commands 306 ...
Страница 318: ...CHAPTER 22 QoS Commands 318 ...
Страница 352: ...CHAPTER 26 SNMP Commands 352 ...
Страница 355: ...CHAPTER 27 HTTPS Commands 355 EXAMPLE HTTPS redirect enable HTTPS ...
Страница 356: ...CHAPTER 27 HTTPS Commands 356 ...
Страница 362: ...CHAPTER 29 UPnP Commands 362 ...
Страница 370: ...CHAPTER 31 Firmware Commands 370 ...
Страница 372: ...SECTION Appendices 372 ...
Страница 386: ...GLOSSARY 386 ...
Страница 390: ...INDEX 390 W web interface access requirements 49 configuration buttons 50 home page 50 menu list 51 panel display 51 ...
Страница 391: ...INDEX 391 ...
Страница 392: ...149100000079A R01 SMC8028L2 ...