CIST Running Information

In this user interface, you can query the CIST running information.

Navigation Path

In the NE Explorer, select the target NE and choose Configuration > Packet Configuration > Ethernet Protocol Configuration > MSTP Configuration from the Function Tree. Then, select the CIST Running Information tab.

Parameters

Field	Value	Description
Port Group ID	Example: 5	Display the port group ID. Only the ID that is automatically allocated can be used.
Protocol Running Mode	MSTP, STP	Display the running mode of the protocol.
Bridge Priority	0 to 61440, in increments of 4096 Default: 32768	Display the bridge priority. The bridge priority determines whether the switch can be used as the root bridge of the spanning tree. Set a low priority to specify a switch as the root of the spanning tree. In the case of different spanning tree instances, one switch that supports the MSTP protocol may be of different priorities.
Bridge MAC Address	Example: 1A-2B-3C-4D-5E-6F	Display the MAC address of the bridge.
Root Bridge Priority	0 to 61440, in increments of 4096 Default: 32768	Display the priority of the root bridge.
Root Bridge MAC Address	Example: 1A-2B-3C-4D-5E-6F	Display the MAC address of the root bridge.
External Path Cost ERPC	Example: 0	Display the external path cost (ERPC). The ERPC refers to the accumulated path cost from the MST domain that the switch belongs to to the CIST root switch.
Domain Root Bridge Priority	0 to 61440, in increments of 4096 Default: 32768	Display the priority of the domain root bridge.
Domain Root Bridge MAC Address	Example: 1A-2B-3C-4D-5E-6F	Display the MAC address of the domain root bridge.
Internal Path Cost IRPC	Example: 0	Display the internal path cost (IRPC). The internal root path cost (IRPC) refers to the accumulated path costs from the port to the IST master switch.
Root Port	Example: Slot-Board Name-Port (Port No.)	Display the priority of the root port.
Root Port Priority	0 to 240, in increments of 16 Default: 128	Display the root port.
Topology Change Identifier	Example: 0	Display the identifier of the topology change.
Last Topology Change Time (s)	Example: 1211	Display the last topology change time.
Topology Change Count	Example: 0	Display the count of the topology change.
Enabled Protocol	Disabled, Enabled Default: Disabled	Display the enable status of the protocol. Enabling the spanning tree protocol causes rearrangement of the topology and service interruption.
Port Role	Root, Designated, Alternate, Backup, Master, Disabled	Display the role of the port. In the case of a non-root switch, the root port refers to the port that is nearest to the root switch. The designated port of a switch refers to the port that forwards the BPDU to the switch on an upstream switch. The alternate port refers to the backup port of the root port. If the root port is blocked, the alternate port becomes the new root port. When the two ports of a switch are connected, a ring exists. Then, the switch blocks one port that is the backup port. The master port refers to the port on the shortest trail that connects the MST domain and the root. It is the port on the switch that connects the MST domain to the root. When the parameter is set to disabled, the port role is disabled.
Port Status	Discarding, Learning, Forwarding	Display the port status. In the discarding status, the port only receives packets of the bridge protocol data (BPDU). In the learning status, the port only receives and transmit the BPDU packets instead of forwarding the user flow. In the forwarding status, the port forward the user flow, and receives and transmit the BPDU packets.
Priority	0 to 240, in increments of 16 Default: 128	Display the port priority. During calculation of the spanning tree, the role of a port basically depends on the port priority. In the case of different spanning tree instances, one port on the switch that supports the MSTP protocol is of different priorities. Hence, one port plays different roles in different spanning tree instances. In this way, the data of different VLANs is transported along different physical paths and the load is shared per VLAN.
Path Cost	1 to 200000000 Default: 20000	Display and set the trail path cost. The path cost depends on the rate of the link connected to the port. In the case of the different spanning tree instances, one port on the switch that supports the MSTP protocol may have different path costs. Set proper path costs to forward the traffic of different VLANs along different physical links. In this way, the load is shared per VLAN.
Designated Port	Example: Slot-Board Name-Port (Port No.)	Display the designated port.
Designated Port Priority	0 to 240, in increments of 16 Default: 0	Display the priority of the designated port.
Remain Hop	Example: 5	Display the remaining hops in the MST domain.
MST Domain Max Hop Count	1 to 40 Default: 20	Display the maximum hop count in the MST domain. The scope of an MST domain depends on the maximum count.
Hello Time (s)	Example: 2	Display and set the hello time. The hello time indicates the period for transmitting the BPDU.
Max Age (s)	Example: 20	Display and set the maximum age time. The maximum age time indicates the maximum aging time of the message.
Message Age	Example: 20	Display and set the message age. This parameter indicates the aging of the message.
Forward Delay (s)	Example: 15	Display and set the forward delay. The forward delay indicates the delay of forwarding.
Port	Example: Slot-Board Name-Port (Port No.)	Display the port.
Edge Port Attribute	Disabled, Enabled Default: Disabled	Display the attribute of the edge port. The edge port indicates the port that is neither directly connected to any switch nor indirectly connected to any switch through the network in connection to the port. If the port specified as the edge port transfers from the congestion status to the forwarding status, the edge port can quickly transfer without the wait of the delay. The user can specify the port connected to the terminal as the edge port.
Actual Port Attribute	Disabled	Display the attribute of the actual edge port.
Point to Point	auto, false, true Default: auto	Display the point-to-point attribute. auto: point-to-point link attributes or non-point-to-point link attributes, as detected false: non-point-to-point link attributes false: point-to-point link attributes The point-to-point link is the direct link between two switches. If a port is connected to a point-to-point link or any other link, the connection of this port is set accordingly on all spanning tree instances. If the physical link connected to a port is not a point-to-point link, incorrect configuration of the link as a point-to-point link may introduce temporary path loop.
Actual Point To Point	false, true	Display the actual point-to-point attributes.
Max Count of Transmitting Message	1 to 255 Default: 3	Display the maximum count of transmitted packets. This parameter indicates the maximum number of MSTP packets that can be transmitted within a hello-time period. In the case of an Ethernet port, the maximum number depends on the network structure and physical state of the port. Set this parameter according to the network. If this parameter is set to an excessively large value, a great number of MSTP packets are transmitted within each hello-time period. As a result, these packets occupy many network resources.