DELL S50V User Manual

Rapid Spanning Tree Protocol | 909

 is available only on platform: 

s

Use RSTP Fast Hellos to achieve sub-second link-down detection so that convergence is triggered faster. 
The standard RSTP link-state detection mechanism does not offer the same low link-state detection speed.

RSTP Fast Hellos decrease the hello interval to the order of milliseconds and all timers derived from the 
hello timer are adjusted accordingly. This feature does not inter-operate with other vendors, and is 
available only for RSTP.

Configure a hello time on the order of milliseconds.

 

Range: 50 - 950 milliseconds

PROTOCOL RSTP

FTOS(conf-rstp)#do show spanning-tree rstp brief 

Executing IEEE compatible Spanning Tree Protocol

    Root ID    Priority 0, Address 0001.e811.2233

    Root Bridge hello time 

50

 ms, max age 20, forward delay 15

    Bridge ID    Priority 0, Address 0001.e811.2233

    We are the root

    Configured hello time 50 ms, max age 20, forward delay 15

Note: The hello time is encoded in BPDUs in increments of 1/256ths of a second. The standard minimum 
hello time in seconds is 1 second, which is encoded as 256. Millisecond hello times are encoded using 
values less than 256; the millisecond hello time equals (x/1000)*256.
Note: When millisecond hellos are configured, the default hello interval of 2 seconds is still used for edge 
ports; the millisecond hello interval is not used.