Specifications

Switching set mstp 8-149
Software Release 2.7.3
C613-03098-00 REV A
The configname parameter specifies the name for the MST region. All the
switches in the same MST region will have the same configuration name. If the
configure name is not set explicitly by the command, the default name for the
MST region is the switch’s MAC address presented as text string. All switches
are in their own MST region by default because MAC addresses are unique.
The revisionlevel parameter specifies the revision level in the MST region. All
the switches in the same MST region will have the same revision number. If the
revision level is not set explicitly by the command, the default revision level
value will be 0.
The forwarddelay parameter sets a delay time, in seconds, that a port waits
before changing its spanning tree state towards the forwarding state. Its
purpose is to allow sufficient time for other ports to receive their spanning tree
information. The delay determines the maximum time taken to transition from
discarding to learning and from learning to forwarding. This value is only used
when the switch is acting as the root bridge. Any switch not acting as the root
bridge uses a dynamic value for the forwarddelay set by the root bridge. The
forwarddelay, maxage, and hellotime parameters are interrelated. See the
formulae below. The default for forwarddelay is 15 seconds.
The hellotime parameter sets the time period, in seconds, between the
transmissions of spanning tree configuration messages. These messages are
transmitted by ports with the 'designated port' role of the spanning tree, or are
trying to become the root bridge. The default is 2 seconds.
The maxage parameter sets the maximum age, in seconds, that dynamic MSTP
configuration information stored in the switch may reach before it is discarded.
The default is 20 seconds.
The forwarddelay, maxage, and hellotime parameters should be set according
to the following formulae, as specified in IEEE Standard 802.1d:
2 x (forwarddelay - 1.0 seconds) >= maxage
maxage >= 2 x (hellotime + 1.0 seconds)
The maxhop parameter specifies the maximum hop count in transmitting
information within an MST region. This is in order to ensure that old
information does not endlessly circulate through redundant paths in the
network, thus preventing the effective propagation of the new information.
The hop count is decremented by each receiving port. Received information is
discarded and the port is made a designated port if the hop count reaches 0.
The default value for maxhop is 20.
The protocolversion parameter specifies which version of the spanning tree
protocol the switch uses.If mstp is specified, the switch uses the full Multiple
Spanning Tree protocol and sends MSTI BPDUs. If RSTP is specified, the switch
uses the Rapid Spanning Tree protocol and sends RST BPDUs. The switch
operates as though it is in a region of its own. If STP is specified, the switch
emulates the Spanning Tree Protocol and transmits STP configuration BPDUs.
Rapid port state transitions are disabled, and the switch operates as if in a
region of its own.
The staticvlans parameter should be turned on when the ports that link to
other switches have static VLAN memberships. In simple static VLAN
configurations it may be possible to operate with this option turned off
provided that redundant links between any pair of switches have the same