ZyXEL Communications GS-3012 Series Switch User Manual


 
Chapter 11 Spanning Tree Protocol
GS-3012/GS-3012F User’s Guide
108
11.4 Rapid Spanning Tree Protocol Status
Click Advanced Application, Spanning Tree Protocol in the navigation panel to display the
status screen as shown next. See Section 11.1 on page 103 for more information on RSTP.
Note: This screen is only available after you activate RSTP on the switch.
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)
Port This field displays the port number.
* Settings in this row apply to all ports.
Use this row only if you want to make some settings the same for all ports. Use this
row first to set the common settings and then make adjustments on a port-by-port
basis.
Note: Changes in this row are copied to all the ports as soon as you
make them.
Active Select this check box to activate RSTP on this port.
Priority Configure the priority for each port here.
Priority decides which port should be disabled when more than one port forms a
loop in a switch. Ports with a higher priority numeric value are disabled first. The
allowed range is between 0 and 255 and the default value is 128.
Path Cost Path cost is the cost of transmitting a frame on to a LAN through that port. It is
assigned according to the speed of the bridge. The slower the media, the higher
the cost - see Table 24 on page 104 for more information.
Apply Click Apply to save your changes to the switch’s run-time memory. The switch
loses these changes if it is turned off or loses power, so use the Save link on the
top navigation panel to save your changes to the non-volatile memory when you
are done configuring.
Cancel Click Cancel to reset the fields.
Table 27 RSTP: Configuration (continued)
LABEL DESCRIPTION