Allied Telesis AT-S86 - Manual (Page 105)

AT-S86 Management Software User’s Guide
105
Configuring the STP Bridge Settings
This section contains the procedure for configuring a bridge’s STP
settings.
Caution
The default STP parameters are adequate for most networks.
Changing them without prior experience and an understanding of
how STP works might have a negative effect on your network. You
should consult the IEEE 802.1d standard before changing any of the
STP parameters.
To configure the bridge settings, perform the following procedure:
1. From the main menu, select Bridge > Spanning Tree.
The Spanning Tree page is shown in Figure 33 on page 102.
2. In the Hello Time field, enter a number for the time interval between
generating and sending configuration messages by the bridge. This
parameter can be from 1 to 10 seconds. The default is 2 seconds.
3. In the Forward Delay field, enter a number for the waiting period in
seconds before a bridge changes to a new state, for example,
becomes the new root bridge after the topology changes. If the bridge
transitions too soon, not all links may have yet adapted to the change,
resulting in network loops. The range is 4 to 30 seconds. The default is
15 seconds.
4. In the Max Age field, enter a number for the length of time after which
stored bridge protocol data units (BPDUs) are deleted by the bridge.
All bridges in a bridged LAN use this aging time to test the age of
stored configuration messages called bridge protocol data units
(BPDUs). For example, if you use the default value 20, all bridges
delete current configuration messages after 20 seconds. This
parameter can be from 6 to 40 seconds.
When you select a value for maximum age, observe the following
rules:
MaxAge must be greater than (2 x (HelloTime + 1)).
MaxAge must be less than (2 x (ForwardingDelay - 1)).
Note
The aging time for BPDUs is different from the aging time used by
the MAC address table.