ZyXEL Communications MSC1000G Series, Руководство пользователя

Страница: 522 / 1168

Chapter 13 Switch Screens
Management Switch Card User’s Guide
522
13.11 Spanning Tree Protocols
The switch supports Spanning Tree Protocol (STP), Rapid Spanning Tree Protocol (RSTP) and
Multiple Spanning Tree Protocol (MSTP) as defined in the following standards.
• IEEE 802.1D Spanning Tree Protocol
• IEEE 802.1w Rapid Spanning Tree Protocol
• IEEE 802.1s Multiple Spanning Tree Protocol
13.11.1 STP and RSTP
RSTP adds rapid reconfiguration capability to STP. The switch supports RSTP and the earlier STP.
RSTP and STP detect and break network loops and provide backup links between switches, bridges
or routers. They allow a device to interact with other RSTP or STP-aware devices in your network to
ensure that only one path exists between any two stations on the network. The switch uses RSTP
by default but can still inter-operate with STP switches (although without RSTP's benefits).
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 tables.
Select All Select this check box to select all of the column’s check boxes. Clear this check box to clear
all of the column’s check boxes.
Cancel Click Cancel to begin configuring this screen afresh.
Table 275
Switch Setup VlanPri
LABEL DESCRIPTION
Table 276
STP Path Costs
LINK SPEED RECOMMENDED VALUE RECOMMENDED RANGE ALLOWED RANGE
4Mbps 250 100 to 1000 1 to 65535
10Mbps 100 50 to 600 1 to 65535
16Mbps 62 40 to 400 1 to 65535
100Mbps 19 10 to 60 1 to 65535
1Gbps 4 3 to 10 1 to 65535
10Gbps 2 1 to 5 1 to 65535
Table 277
MSTP/RSTP Path Costs
LINK SPEED RECOMMENDED VALUE RECOMMENDED RANGE ALLOWED RANGE
<= 100 Kbps 200 000 000 200 000 000 to 200 000 000 1 to 200 000 000
1 Mbps 20 000 000 2 000 000 to 200 000 000 1 to 200 000 000
10 Mbps 2 000 000 200 000 to 20 000 000 1 to 200 000 000
100 Mbps 200 000 20 000 to 2 000 000 1 to 200 000 000
1 Gbps 20 000 2000 to 200 000 1 to 200 000 000
10 Gbps 2000 200 to 20 000 1 to 200 000 000
100 Gbps 200 20 to 2000 1 to 200 000 000