GarrettCom MNS-6K-SECURE 14.1.4 Manual De Usuario

apid Spanning Tree Protocol (RTSP), like STP,  was designed to avoid loops in an Ethernet 
network. Rapid Spanning Tree Protocol (RSTP) (IEEE 802.1w) is an evolution of the 
Spanning Tree Protocol (STP) (802.1d standard) and provides for faster spanning tree 
convergence after a topology change. 

 

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he IEEE 802.1d Spanning Tree Protocol (STP) was developed to allow 

e construction of robust networks that incorporate redundancy while 

pruning the active topology of the network to prevent loops. While STP is 

effective, it requires that frame transfer must halt after a link outage. This halt is until all 
bridges in the network are sure to be aware of the new topology. Using STP (IEEE 
802.1d) recommended values, this period lasts 30 seconds. 

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Rapid Spanning Tree Protocol (IEEE 802.1w) is a further evolution of the 802.1d 
Spanning Tree Protocol. It replaces the settling period with an active handshake between 
switches (bridges) that guarantees topology information to be rapidly propagated through 
the network.  IEEE 802.1D-2004 proposes a new standard for faster recovery for up to 
16 switches. GarrettCom implements the IEEE 802.1D-2004 and enhancements to cover 
more than 16 switches for larger networks. RSTP converges in less than one second to six 
seconds. RSTP also offers a number of other significant innovations. These include 

•  Topology changes in STP must be passed to the root bridge before they can be 

propagated to the network. Topology changes in RSTP can be originated from 
and acted upon by any designated switch (bridge), leading to more rapid 
propagation of address information 

•  STP recognizes one state - blocking for ports that should not forward any data or 

information. RSTP explicitly recognizes two states or blocking roles - alternate and 
backup port including them in computations of when to learn and forward and 
when to block 

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