DELL S50V User Manual

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Rapid Spanning Tree Protocol

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•

To add an interface to the Rapid Spanning Tree topology, configure it for Layer 2 and it is 
automatically added. If you previously disabled RSTP on the interface using the command 

, re-enable it using the command 

.

•

Remove an interface from the Rapid Spanning Tree topology using the command 

. 

See also 

 for BPDU Filtering 

behavior.

You can modify Rapid Spanning Tree parameters. The root bridge sets the values for forward-delay, 
hello-time, and max-age and overwrites the values set on other bridges participating in the Rapid Spanning 
Tree group.

•

Forward-delay is the amount of time an interface waits in the Listening State and the Learning State 
before it transitions to the Forwarding State.

•

Hello-time is the time interval in which the bridge sends RSTP Bridge Protocol Data Units (BPDUs).

•

Max-age is the length of time the bridge maintains configuration information before it refreshes that 
information by recomputing the RST topology.

Note: Dell Force10 recommends that only experienced network administrators change the Rapid Spanning 
Tree group parameters. Poorly planned modification of the RSTG parameters can negatively impact 
network performance.

R3#show spanning-tree rstp brief

Executing IEEE compatible Spanning Tree Protocol

Root ID    Priority 32768, Address 0001.e801.cbb4

Root Bridge hello time 2, max age 20, forward delay 15

Bridge ID    Priority 32768, Address 0001.e80f.1dad

Configured hello time 2, max age 20, forward delay 15

Interface                                        Designated

 Name      PortID   Prio Cost    Sts Cost        Bridge ID        PortID

---------- -------- ---- ------- --- ------- -------------------- --------

Gi 3/1     128.681  128  20000   BLK 20000   32768 0001.e80b.88bd 128.469

Gi 3/2     128.682  128  20000   BLK 20000   32768 0001.e80b.88bd 128.470

Gi 3/3     128.683  128  20000   FWD 20000   32768 0001.e801.cbb4 128.379

Gi 3/4     128.684  128  20000   BLK 20000   32768 0001.e801.cbb4 128.380

Interface

 Name      Role   PortID   Prio Cost    Sts Cost    Link-type Edge

---------- ------ -------- ---- ------- --- ------- --------- ----

Gi 3/1     Altr   128.681  128  20000   BLK 20000   P2P       No

Gi 3/2     Altr   128.682  128  20000   BLK 20000   P2P       No

Gi 3/3     Root   128.683  128  20000   FWD 20000   P2P       No

Gi 3/4     Altr   128.684  128  20000   BLK 20000   P2P       No

R3#