Bridge Parameters

In this interface, you can modify and query bridge parameters.

Navigation Path

In the NE Explorer, select the board and choose Configuration > Layer-2 Switching Management > Multiple Spanning Tree, click the Bridge Parameters tab. Click Bridge Parameters in the lower pane.

Parameters

**Table 1** Descriptions of the parameters for Bridge Parameters
Field	Value	Description
VBID	Example: 2	Displays the ID of the Virtual Bridge.
MST Domain Name	Character string of 32 bytes	Displays and sets the MST domain name. Modification of the MST domain name causes change of the network topology. Two switches belong to the same MST domain only when the MST domains configured on the two switches have the same name, when all VLAN mapping tables corresponding to the spanning tree instances in the MST domains are the same, and when redaction levels of the MST domains are the same and the two MST domains are directly connected.
Redaction Level	0-65535	Displays and sets the redaction level. Modification of the redaction level causes change of the network topology.
Mapping List	1-300	Sets the mapping list. Modification of the mapping list causes change of the network topology.
MST Domain Max Hop Count	1-40	Displays the maximum count of hops in an MST domain. The scope of an MST domain depends on the maximum count.
Network Diameter	2-7	Displays and sets the network diameter. The network diameter is the length of the trail with the most switches in the network. The count of switches on the trail indicates the network diameter. The network diameter is one parameter of the network scope, which increases with the network diameter. The network diameter is valid only for CIST but for MIST. When the user configures the network diameter of a switch, the MSTP performs calculation and sets Hello Time, Forward Delay and Max Age to reasonable values.
Hello Time (s)	1 to 10	Displays and sets the hello time. A switch uses this parameter to check whether the link is faulty. The switch sends hello packets to surrounding switches every hello time to check whether there are link faults. NOTE: The parameters of the bridge time are recommended to be optimized through the configuration of the network diameter, instead of the configuration of the Forward Delay, Hello Time, and Max Age bridge time parameters. When the bridge time parameters are configured, the value of the diameter of the switching network is invalid. For the Forward Delay, Hello Time, and Max Age bridge, the following constraints should be met: 2(hellotime+1) ≤ maxage ≤ 2(forwarddelay-1).
Max Age (s)	6 to 40	Displays and sets the maximum age. This parameter is used to judge whether the configuration message expires. The switch will discard the expired configuration message.
Forward Delay (s)	4 to 30	Displays and sets the forward delay. The forward delay time is used during the bridge state transition. The link fault results in the recalculation of the spanning tree and then the structure of the spanning tree is changed. The new configuration message cannot be transmitted over the entire network immediately. If the new root port and designated port forward the data immediately, a temporary loop may occur. Therefore, a state transition mechanism is adopted. That is, the root port and the designated port must stay in a transition state before they can forward data. The transition state turns into the forwarding state upon Forward Delay. This delay guarantees that the new configuration message has spread throughout the entire network.