User`s manual
User’s Manual 41
• Default: 20
• Minimum: The higher of 6 or [2 x (Hello Time + 1)].
• Maximum: The lower of 40 or [2 x (Forward Delay - 1)]
Forward Delay – The maximum time (in seconds) this device will wait before changing states (For example,
discarding to learning to forwarding). This delay is required because every device must receive information
about topology changes before it starts to forward frames. In addition, each port needs time to listen for
conflicting information that would make it return to a discarding state; otherwise, temporary data loops might
result.
• Default: 15
• Minimum: The higher of 4 or [(Max. Message Age / 2) + 1]
• Maximum: 30
3.1.3 Configuration Settings for RSTP
The following attributes apply to both RSTP and MSTP:
Path Cost Method – The path cost is used to determine the best path between devices. The path cost
method is used to determine the range of values that can be assigned to each interface.
• Long: Specifies 32-bit based values that range from 1-200,000,000. (This is the default.)
• Short: Specifies 16-bit based values that range from 1-65535.
Transmission Limit – The maximum transmission rate for BPDUs is specified by setting the minimum interval
between the transmission of consecutive protocol messages. (Range: 1-10; Default: 3)
3.1.4 Configuration Settings for MSTP
The following configuration settings apply to the MSTP.
Max Instance Numbers – The maximum number of MSTP instances to which this switch can be assigned.
(Default: 65)
Region Revision* – The revision for this MSTI. (Range: 0-65535; Default: 0)
Region Name* – The name for this MSTI. (Maximum length: 32 characters)
Maximum Hop Count – The maximum number of hops allowed in the MST region before a BPDU is
discarded. (Range: 1-40; Default: 20)
Note: The MST name and revision number are both required to uniquely identify an MST region.
Configuring Switch Using the Web or CLI
Web
Click Spanning Tree – STA, Configuration. Modify the required attributes, and click Apply.