Specifications

Switching set stp 8-159
Software Release 2.7.3
C613-03098-00 REV A
multiple of 4096, the value is rounded down to the nearest multiple of 4096.
The rounding scheme is defined in Table 8-30.
The priority parameter sets the priority of the switch to become the Root
Bridge. The lower the value of the Bridge Identifier, the higher the priority. If
the priority parameter is set by specifying the priority or default parameters,
the specified STP is initialised. Counters for the STP are not affected. The
default for priority is 32768.
The rstptype parameter specifies how the RSTP algorithm operates. If normal
is specified, then the algorithm uses rapid port role transitions and transmits
and receives RST BPDUs. If stpcompatible is specified, then rapid transitions
are disabled, standard BPDUs are transmitted and RST BPDUs are discarded.
Setting rstptype to stpcompatible allows RSTP to support applications and
protocols that may be sensitive to frame duplication and misordering, for
example NetBeui. The default is normal.
Setting rstptype to normal when normal has already been set, sets all ports to
the “sending RSTP” state. This is referred to in the IEEE Standard 802.1w
standard as mCheck and is useful for restoring full rapid mode operation when
one or more ports on the switch has entered the “sending STP” state.
RSTP-capable devices with rstp set to normal that receive the RST BPDUs enter
the “sending RSTP” state. When an STP BPDU is received after the mCheck
operation, either as a result of a device being in rapid mode with rstptype set to
stpcompatible or as a result of a device in standard mode, the ports that
received the STP BPDUs revert to the “sending STP” state.
Examples To set the forward delay to 22 seconds for the company STP, use the command:
set stp=company forwarddelay=2
Table 8-30: Rounding scheme for ranges of priority parameter values when the mode
parameter is set to rapid
Lower boundary Upper boundary Rounded RSTP
Bridge Priority Value
0 4095 0
4096 8191 4096
8192 12287 8192
12288 16383 12288
16384 20479 16384
20480 24575 20480
24576 28671 24576
28672 32767 28672
32768 36863 32768
36864 40959 36864
40960 45055 40960
45056 49151 45056
49152 53247 49152
53248 57343 53248
57344 61439 57344
61440 65535 61440