Dell Force10 S4820T S4820T Configuration Guide - Page 815

Figure 41-8. bridge-priority Command Example FTOS(conf-rstp)#bridge-priority 4096 04:27:59: %RPM0-P:RP2 %SPANMGR-5-STP_ROOT_CHANGE: RSTP root changed. My Bridge ID: 4096:0001.e80b.88bd Old Root: 32768:0001.e801.cbb4 New Root: 4096:0001.e80b.88bd Old root bridge ID New root bridge ID SNMP Traps for Root Elections and Topology Changes Enable SNMP traps for RSTP, MSTP, and PVST+ collectively using the command snmp-server enable traps xstp. Fast Hellos for Link State Detection s Fast Hellos for Link State Detection is available only on platform: 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. Task Command Syntax Configure a hello time on the order of milliseconds. hello-time milli-second interval Range: 50 - 950 milliseconds 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 Command Mode PROTOCOL RSTP 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. Rapid Spanning Tree Protocol (RSTP) | 815