Chapter 53 Spanning Tree Protocol
XGS2220 Series User’s Guide
356
Figure 255
SWITCHING > Spanning Tree Protocol > MSTP
The following table describes the labels in this screen.
Table 189 SWITCHING > Spanning Tree Protocol > MSTP
LABEL
DESCRIPTION
Bridge
Active
Enable the switch button to activate MSTP on the Switch. Disable the switch to disable MSTP
on the Switch.
Note: You must also activate
Multiple Spanning Tree (MSTP)
in the
SWITCHING
>
Spanning Tree Protocol
>
Spanning Tree Setup
screen to enable MSTP on the
Switch.
Hello Time
This is the time interval in seconds between BPDU (Bridge Protocol Data Units) configuration
message generations by the root switch. The allowed range is 1 to 10 seconds.
Max Age
This is the maximum time (in seconds) a switch can wait without receiving a BPDU before
attempting to reconfigure. All switch ports (except for designated ports) should receive BPDUs
at regular intervals. Any port that ages out STP information (provided in the last BPDU)
becomes the designated port for the attached LAN. If it is a root port, a new root port is
selected from among the Switch ports attached to the network. The allowed range is 6 to 40
seconds.
Forwarding Delay
This is the maximum time (in seconds) a switch will wait before changing states. This delay is
required because every switch 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 blocking state; otherwise, temporary data loops might result.
The allowed range is 4 to 30 seconds. As a general rule:
Note: 2 * (Forward Delay
–
1) >= Max Age >= 2 * (Hello Time + 1)
Maximum hops
Enter the number of hops (between 1 and 255) in an MSTP region before the BPDU is
discarded and the port information is aged.
Configuration
Name
Enter a descriptive name (up to 32 printable ASCII characters except [ ? ], [ | ], [ ' ], [ " ], or [ ,
]) of an MST region.
