SETUP
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DOC_DEV_XS_Setup guide_C
Forward delay
When a port changes state following a topology change, it goes through 3 states :
•
Blocked :
All ingress traffic is discarded but BPDU frames (necessary for STP function)
•
Listening/Learning :
The port listens to the traffic but does not forward data. This is used to detect
transient loops that can be created during the convergence.
•
Forwarding :
The port forwards data.
The forward delay is the duration of the Listening/Learning state.
Remark : Ports configured as Edge ports or P2P ports ignore this setting and skip the listening step
altogether because it becomes unnecessary and increases the convergence time.
Maximum age
When the STP root transmits a BPDU, the information contained in it is forwarded from bridge to bridge. At
each retransmission, a bridge adds 1 to a counter in the data. When this counter exceeds the "Max Age"
value, the BPDU is not forwarded.
Note 1 : This acts like the TTL in IP packets.
Note 2 : This value must be large enough for the network. Each device must be able to receive the BPDUs
from the root, even if it is located a lot of devices away. For example, for a ring with 20 devices, you must
have "Max Age" greater than 20. Otherwise strange problems like erratic behavior, very long convergence
time, or no convergence at all will occur.
Age increment
Increment value of age counter when going through the bridge.
Summary of Contents for XLAN+ Series
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