ZyXEL Communications AAM1212, User Manual

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AAM1212 User’s Guide
132 Chapter 14 Spanning Tree Protocol
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:
2 * (Forward Delay - 1) >= Max Age >= 2 * (Hello Time + 1)
Port This field identifies the Ethernet port.
Active Select this check box to activate STP 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 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.
Apply Click Apply to save your changes to the AAM’s volatile memory. The AAM 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.
Cancel Click Cancel to begin configuring this screen afresh.
Table 36 Spanning Tree Protocol: Configuration (continued)
LABEL DESCRIPTION