ZyXEL Communications IES-22A User Manual page 174

Chapter 23 Spanning Tree Protocol
Table 52 Advanced Application > Spanning Tree Protocol > STP Config (continued)
LABEL
Hello Time
MAX Age
Forwarding Delay
Port
Active
Priority
Path Cost
Apply
Cancel
174
DESCRIPTION
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.
This is the maximum time (in seconds) the IES-708-22A can wait without
receiving a BPDU before attempting to reconfigure. All 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 IES-708-22A ports attached to the network. The allowed range is 6 to 40
seconds.
This is the maximum time (in seconds) the IES-708-22A 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)
This field identifies the Ethernet port.
Select this check box to activate STP on this port.
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 default value is 128.
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.
Click Apply to save your changes to the IES-708-22A's volatile memory. The
IES-708-22A loses these changes if it is turned off or loses power, so use the
Config Save link on the navigation panel to save your changes to the non-
volatile memory when you are done configuring.
Click Cancel to begin configuring this screen afresh.
IES-708-22A User's Guide