25. Spanning Tree
ROX™ v2.2 User Guide
244
RuggedBackbone™ RX5000
STP Protocol Version
Synopsis: string - one of the following keywords { mstp, rstp, stp }
Default: rstp
The version of the Spanning Tree Protocol to support, either only STP or Rapid STP or Multiple STP
Hello Time (sec)
Synopsis: unsigned integer
Default: 2
The time between configuration messages issued by the root bridge. Shorter hello times result
in faster detection of topology changes at the expense of moderate increases in STP traffic.
(Relationship : maxAgeTime >= 2 * (hel 1.0 seconds))
Max Age (sec)
Synopsis: unsigned integer
Default: 20
The time for which a configuration message remains valid after being issued by the root bridge.
Configure this parameter with care when many tiers of bridges exist, or slow speed links (such as
those used in WANs) are part of the network. (Relationship : maxAgeTime >= 2 * (hel 1.0
seconds))
Transmission Hold Count
Synopsis: unsigned integer
Default:
The maximum number of configuration messages on each port that may be sent in a special
event (such as recovering from a failure or bringing up a new link). After the maximum number
of messages is reached, RSTP will be limited to 1 message per second. Larger values allow the
network to recover from failed links more quickly. If RSTP is being used in a ring architecture, the
transmit count should be larger than the number of switches in the ring. If unset, then the value is
interpreted as unlimited (default).
Forwarding Delay (sec)
Synopsis: unsigned integer
Default: 15
The amount of time a bridge spends learning MAC addresses on a rising port before beginning to
forward traffic. Lower values allow the port to reach the forwarding state more quickly, but at the
expense of flooding unlearned addresses to all ports.
Maximum Hops
Synopsis: unsigned integer
Default: 20
This parameter is only relevant for MSTP; ignore it otherwise. This parameter specifies the
maximum possible bridge diameter inside an MST region. MSTP BPDUs propagating inside an
MST region carry a time-to-live parameter decremented by every switch that propagates the BPDU.
If the maximum number of hops inside the region exceeds the configured maximum, BPDUs may
be discarded due to their time-to-live information.
MST Region Name
Synopsis: A string
This is used to configure a new region from a subset of switches in a current region, while
maintaining the same region name.
MST Revision Level
Synopsis: unsigned integer