Chapter 6 Wireless Settings Screen
ZyXEL NWA-1100 User’s Guide
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6.5.2.2 STP Terminology
The root bridge is the base of the spanning tree; it is the bridge with the lowest
identifier value (MAC address).
Path cost is the cost of transmitting a frame onto a LAN through that port. It is
assigned according to the speed of the link to which a port is attached. The slower
the media, the higher the cost - see the following table.
On each bridge, the root port is the port through which this bridge communicates
with the root. It is the port on this switch with the lowest path cost to the root (the
root path cost). If there is no root port, then this bridge has been accepted as the
root bridge of the spanning tree network.
For each LAN segment, a designated bridge is selected. This bridge has the lowest
cost to the root among the bridges connected to the LAN.
6.5.2.3 How STP Works
After a bridge determines the lowest cost-spanning tree with STP, it enables the
root port and the ports that are the designated ports for connected LANs, and
disables all other ports that participate in STP. Network packets are therefore only
forwarded between enabled ports, eliminating any possible network loops.
STP-aware bridges exchange Bridge Protocol Data Units (BPDUs) periodically.
When the bridged LAN topology changes, a new spanning tree is constructed.
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 (Max Age), the bridge
assumes that the link to the root bridge is down. This bridge then initiates
negotiations with other bridges to reconfigure the network to re-establish a valid
network topology.
Table 12
STP Path Costs
LINK SPEED
RECOMMENDE
D VALUE
RECOMMENDE
D RANGE
ALLOWED
RANGE
Path Cost
4Mbps
250
100 to 1000
1 to 65535
Path Cost
10Mbps
100
50 to 600
1 to 65535
Path Cost
16Mbps
62
40 to 400
1 to 65535
Path Cost
100Mbps
19
10 to 60
1 to 65535
Path Cost
1Gbps
4
3 to 10
1 to 65535
Path Cost
10Gbps
2
1 to 5
1 to 65535
Содержание NWA-1100
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Страница 8: ...Safety Warnings ZyXEL NWA 1100 User s Guide 8 ...
Страница 10: ...Contents Overview ZyXEL NWA 1100 User s Guide 10 ...
Страница 16: ...Table of Contents ZyXEL NWA 1100 User s Guide 16 ...
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Страница 32: ...Chapter 2 Introducing the Web Configurator ZyXEL NWA 1100 User s Guide 32 ...
Страница 46: ...46 ...
Страница 54: ...Chapter 5 System Screens ZyXEL NWA 1100 User s Guide 54 ...
Страница 72: ...Chapter 6 Wireless Settings Screen ZyXEL NWA 1100 User s Guide 72 ...
Страница 92: ...Chapter 8 RADIUS Screen ZyXEL NWA 1100 User s Guide 92 ...
Страница 96: ...Chapter 9 MAC Filter Screen ZyXEL NWA 1100 User s Guide 96 ...
Страница 100: ...Chapter 10 IP Screen ZyXEL NWA 1100 User s Guide 100 ...
Страница 136: ...Chapter 15 Troubleshooting ZyXEL NWA 1100 User s Guide 136 ...
Страница 138: ...138 ...
Страница 142: ...Appendix B Power over Ethernet PoE Specifications ZyXEL NWA 1100 User s Guide 142 ...
Страница 144: ...Appendix C Power Adaptor Specifications ZyXEL NWA 1100 User s Guide 144 ...
Страница 198: ...Appendix H Text File Based Auto Configuration ZyXEL NWA 1100 User s Guide 198 ...
Страница 214: ...Appendix J Open Software Announcements ZyWALL USG 300 User s Guide 214 ...
Страница 225: ...Index ZyXEL NWA 1100 User s Guide 225 ...