Cisco Cisco Aironet 340 Ethernet Bridges Mode D'Emploi
Using the Spanning-Tree Protocol 8 - 13
Setting the Hello Message Interval Time (Hello_Time)
The hello_time option is used to set the interval time, in seconds,
between the transmission of configuration messages. This value is only
used if the local bridge becomes the spanning tree root bridge. If not,
the value in received configuration messages transmitted from the root
bridge is used.
between the transmission of configuration messages. This value is only
used if the local bridge becomes the spanning tree root bridge. If not,
the value in received configuration messages transmitted from the root
bridge is used.
If the interval time is set too high, the infrastructure will respond slowly
in resolving any conflict problems. However, if set too low, the infra-
structure will be crowded with hello message traffic. The interval time
values range between 1 and 10 with a default value of 2.
in resolving any conflict problems. However, if set too low, the infra-
structure will be crowded with hello message traffic. The interval time
values range between 1 and 10 with a default value of 2.
Setting the Forwarding Delay Time (Forward_Delay)
The forward_delay option is used to set the delay time, in seconds, that
the ports will spend in the listening and learning states. This value is
only used if the local bridge becomes the spanning tree root bridge. If
not, the value in received configuration messages transmitted from the
root bridge is used.
the ports will spend in the listening and learning states. This value is
only used if the local bridge becomes the spanning tree root bridge. If
not, the value in received configuration messages transmitted from the
root bridge is used.
This option is also the timeout period used to age learned addresses
whenever the spanning tree topology is changed. The value should be at
least twice the transit time of a packet sent from one end of the infra-
structure to the other. This allows for news of a topology change to
reach all nodes and allows all ports to be blocked before new ports enter
the forwarding state.
whenever the spanning tree topology is changed. The value should be at
least twice the transit time of a packet sent from one end of the infra-
structure to the other. This allows for news of a topology change to
reach all nodes and allows all ports to be blocked before new ports enter
the forwarding state.
If the interval time is set too low, then temporary loops could be formed.
However, if set too high, it will take longer for the infrastructure to
become active after a spanning tree topology change has been made. The
delay time values range between 4 and 30 with a default value of 15.
However, if set too high, it will take longer for the infrastructure to
become active after a spanning tree topology change has been made. The
delay time values range between 4 and 30 with a default value of 15.
Setting the Receive Hello Message Timeout (Msg_age_timeout)
The msg_age_timeout option is used to set the timeout period, in sec-
onds, a blocked or root port watches for configuration messages from
the infrastructure’s designated port. This value is only used if the local
bridge becomes the spanning tree bridge. If not, the value received in
configuration messages transmitted from the root bridge is used.
onds, a blocked or root port watches for configuration messages from
the infrastructure’s designated port. This value is only used if the local
bridge becomes the spanning tree bridge. If not, the value received in
configuration messages transmitted from the root bridge is used.
Each time a configuration message is received, the timer is started. If
the timer expires, the root bridge is assumed to have failed and the span-
ning tree infrastructure will be reconfigured.
the timer expires, the root bridge is assumed to have failed and the span-
ning tree infrastructure will be reconfigured.