Alcatel-Lucent 6850-48 Guida Di Riferimento
Distributed Spanning Tree Commands
OmniSwitch CLI Reference Guide
September 2009
page 15-41
bridge forward delay
Configures the bridge forward delay time for the flat mode Common and Internal Spanning Tree (CIST)
instance or for 1x1 mode VLAN instance. This value is the amount of time, in seconds, that determines
how fast a port changes its Spanning Tree state until it reaches a forwarding state. The forward delay time
specifies how long a port stays in the listening and learning states, which precede the forwarding state.
instance or for 1x1 mode VLAN instance. This value is the amount of time, in seconds, that determines
how fast a port changes its Spanning Tree state until it reaches a forwarding state. The forward delay time
specifies how long a port stays in the listening and learning states, which precede the forwarding state.
bridge [instance] forward delay seconds
Syntax Definitions
instance
The flat mode CIST instance or an existing VLAN ID number (1–4094).
seconds
Forward delay time, in seconds (4–30).
Defaults
By default, the bridge forward delay time value is set to 15 seconds.
Platforms Supported
OmniSwitch 6400, 6850, 6855, 9000, 9000E
Usage Guidelines
• A low forward delay time can cause temporary loops in the network, because data may get forwarded
before the reconfiguration message has reached all nodes on the network.
• The forward delay time is also used to age out all dynamic MAC address entries in the forwarding
table (MAC address table) when a topology change occurs.
• Specifying an instance number with this command when the switch is running in the 1x1 Spanning
Tree mode implies a VLAN ID and configures the forward delay time for the associated VLAN
instance.
instance.
• To configure the forward delay time for the flat mode CIST instance when the switch is running in
either the flat or 1x1 mode, do not specify an instance number. The CIST is the instance configured by
default with this command.
default with this command.
• If the switch is running in the flat mode and STP or RSTP is the active protocol, entering 1 to specify
the CIST instance is optional. If MSTP is the active protocol, however, entering 1 for the instance
number is not accepted.
number is not accepted.
• Note that for Multiple Spanning Tree Instances (MSTI), the forward delay time is inherited from the
CIST instance and is not a configurable parameter.
Examples
-> bridge mode flat
-> bridge forward delay 30
-> bridge mode 1x1
-> bridge 255 forward delay 10
-> bridge forward delay 30