Hey there,
This case mainly talks about how to change LPU connection mode stack to MPU connection mode stack on the CE12800.
Problem
Based on the connection mode of the stack management link, the connection modes of stack members are classified into the following types:
MPU connection mode: also called out-of-band stacking. In this mode, stack management links are connected through dedicated SIP interfaces on MPUs to isolate management links from forwarding links, improving reliability. As shown in the following figure, the stack management link is the SIP port on the MPU, and the data forwarding link is the service port added to the stack port.


LPU connection mode: This mode is also called in-band stacking. In this mode, service ports are directly added to stack-ports through stack management links, and data forwarding links are integrated. Dedicated ports on MPUs are not required, simplifying network deployment and maintenance. As shown in the following figure, the management link and data forwarding link are service interfaces added to the stack port.

The reliability and service continuity of MPU connection mode stack are much higher than those of LPU connection mode stack. How to change LPU connection mode stack to MPU connection mode stack?
Solution
Resolution Summary
Change the stack mode to MPU connection mode stack, connect cables to SIP ports on MPUs, save the configuration, and restart the switch.
Resolution Details
1. Run the "undo stack member 1 link-type linecard-direct" and "undo stack member 2 link-type linecard-direct" command in the stack view to delete the LPU connection mode stack configuration.

2. Run the "display dual-active" command to query the stack DAD detection interface. If the stack DAD detection is configured, delete the interface. Enter the DAD detection interface view and run the "undo dual-active detect mode direct" command.
interface Stack-Port1/1
undo dual-active detect mode direct
interface Stack-Port2/1
undo dual-active detect mode direct

3. Connect the SIP ports of the two control boards according to the following figure. Assume that the control boards are 1/9 and 2/9.
Connecting the interface Sip1/9/0/0 to the interface Sip2/9/0/0
Connecting the interface Sip1/9/0/1 to the interface Sip2/10/0/0
Connecting the interface Sip1/10/0/0 to the interface Sip2/9/0/1
Connecting the interface Sip1/10/0/1 to the interface Sip2/10/0/1

If a network cable is used, use the port in the red box in the following figure. If an optical port is used, use the port in the blue box in the following figure.

4. Save the current configuration file and reboot the system.
This is the case of changing stack mode, hope it is of help to you.


