How Rstp Differs To Stp; Stp Example - 3Com SuperStack 3 3812 Implementation Manual

How RSTP Differs to
STP

STP Example

RSTP works in a similar way to STP, but it includes additional information
in the BPDUs. This information allows each bridge to confirm that it has
taken action to prevent loops from forming when it wants to enable a
link to a neighbouring bridge. This allows adjacent bridges connected via
point-to-point links to enable a link without having to wait to ensure all
other bridges in the network have had time to react to the change.
So the main benefit of RSTP is that the configuration decision is made
locally rather than network-wide which is why RSTP can carry out
automatic configuration and restore a link faster than STP.
Figure 9 shows a LAN that has STP enabled. The LAN has three segments,
and each segment is connected using two possible links.
Figure 9 Port costs in a network
Bridge A has the lowest Bridge Identifier in the network, and has
■
therefore been selected as the Root Bridge.
How STP Works 45