Black Box LE2700A, User Manual, Page: 27 / 154

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Page 27
Chapter 4: Redundancy
Table 4-3. MRP configuration screen options.
Label Description
Enable Enables the MRP function
Manager Every MRP topology needs a MRP manager. One MRP topology can only have a
Manager. If two or more switches are set to be Manager, the MRP topology will
fail.
React on Link Change
(Advanced mode) Faster mode. Enabling this function will cause MRP topology to converge more
rapidly. This function only can be set in MRP manager switch.
1st Ring Port Chooses the port which connects to the MRP ring
2nd Ring Port Chooses the port which connects to the MRP ring
4.4 STP/RSTP/MSTP
4.4.1 STP/RSTP
STP (Spanning Tree Protocol), and its advanced versions RSTP (Rapid Spanning Tree Protocol) and MSTP (Multiple Spanning Tree
Protocol), are designed to prevent network loops and provide network redundancy. Network loops occur frequently in large net-
works as when two or more paths run to the same destination, broadcast packets may get in to an infinite loop and hence caus-
ing congestion in the network. STP can identify the best path to the destination, and block all other paths. The blocked links will
stay connected but inactive. When the best path fails, the blocked links will be activated. Compared to STP which recovers a link
in 30 to 50 seconds, RSTP can shorten the time to 5 to 6 seconds.
STP Bridge Status
This page shows the status for all STP bridge instances.
Figure 4-2. STP bridge screen.
Table 4-4. STP bridge screen options.
Label Description
MSTI The bridge instance. You can also link to the STP detailed bridge status.
Bridge ID The bridge ID of this bridge instance.
Root ID The bridge ID of the currently selected root bridge.
Root Port The switch port currently assigned the root port role.
Root Cost Root path cost. For a root bridge, this is zero. For other bridges, it is the sum of
port path costs on the least cost path to the Root Bridge.
Topology Flag The current state of the Topology Change Flag for the bridge instance.
Topology Change Last The time since last Topology Change occurred.
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