Issue Description：
Ring topology stack mode doesn't work between 3 CE6810 switches 
Alarm Information：
HUAWEI> system-view
[~HUAWEI] sysname SwitchA
[*HUAWEI] commit
[~SwitchA] stack
[~SwitchA-stack] stack member 1 priority 150
[*SwitchA-stack] stack member 1 domain 10
[*SwitchA-stack] quit
[*SwitchA] commit
<HUAWEI> system-view
[~HUAWEI] sysname SwitchB
[*HUAWEI] commit
[~SwitchB] stack
[~SwitchB-stack] stack member 1 priority 120
[*SwitchB-stack] stack member 1 domain 10
[*SwitchB-stack] stack member 1 renumber 2 inherit-config
Warning: The stack configuration of member ID 1 will be inherited to member ID 2 after the device resets. Continue? [Y/N]: y
[*SwitchB-stack] quit
[*SwitchB] commit
<HUAWEI> system-view
[~HUAWEI] sysname SwitchC
[*HUAWEI] commit
[~SwitchC] stack
[~SwitchC-stack] stack member 1 priority 90
[*SwitchC-stack] stack member 1 domain 10
[*SwitchC-stack] stack member 1 renumber 3 inherit-config
Warning: The stack configuration of member ID 1 will be inherited to member ID 3 after the device resets. Continue? [Y/N]: y
[*SwitchC-stack] quit
[*SwitchC] commit
[~SwitchA] interface stack-port 1/1
[*SwitchA-Stack-Port1/1] port member-group interface 10ge 1/0/1 to 1/0/2
Warning: After the configuration is complete,
1.The interface(s) (10GE1/0/1-1/0/4) will be converted to stack mode and be configured with the port crc-statistics trigger error-down command if the configuration does not exist.
2.The interface(s) may go Error-Down (crc-statistics) because there is no shutdown configuration on the interfaces.Continue? [Y/N]: y
[*SwitchA-Stack-Port1/1] quit
[*SwitchA] interface stack-port 1/2
[*SwitchA-Stack-Port1/2] port member-group interface 10ge 1/0/3 to 1/0/4
[*SwitchA-Stack-Port1/2] quit
[*SwitchA] commit
[~SwitchA] quit
[~SwitchB] interface stack-port 1/1
[*SwitchB-Stack-Port1/1] port member-group interface 10ge 1/0/1 to 1/0/2
Warning: After the configuration is complete,
1.The interface(s) (10GE1/0/1-1/0/4) will be converted to stack mode and be configured with the port crc-statistics trigger error-down command if the configuration does not exist.
2.The interface(s) may go Error-Down (crc-statistics) because there is no shutdown configuration on the interfaces.Continue? [Y/N]: y
[*SwitchB-Stack-Port1/1] quit
[*SwitchB] interface stack-port 1/2
[*SwitchB-Stack-Port1/2] port member-group interface 10ge 1/0/3 to 1/0/4
[*SwitchB-Stack-Port1/2] quit
[*SwitchB] commit
[~SwitchB] quit
[~SwitchC] interface stack-port 1/1
[*SwitchC-Stack-Port1/1] port member-group interface 10ge 1/0/1 to 1/0/2
Warning: After the configuration is complete,
1.The interface(s) (10GE1/0/1-1/0/4) will be converted to stack mode and be configured with the port crc-statistics trigger error-down command if the configuration does not exist.
2.The interface(s) may go Error-Down (crc-statistics) because there is no shutdown configuration on the interfaces.Continue? [Y/N]: y
[*SwitchC-Stack-Port1/1] quit
[*SwitchC] interface stack-port 1/2
[*SwitchC-Stack-Port1/2] port member-group interface 10ge 1/0/3 to 1/0/4
[*SwitchC-Stack-Port1/2] quit
[*SwitchC] commit
[~SwitchC] quit
Handling Process：
1. check customer provide diagnose information , we can found the stack configuration wrong .
display stack topology
===============================================================================
Stack Topology:
----------------------------------------------
Stack-Port 1 Stack-Port 2
MemberID Status Neighbor Status Neighbor
----------------------------------------------
1 up 2 -- --
2 up 1 -- --
----------------------------------------------
Stack Link:
----------------------------------------------------------------------------
Stack-Port Port Status PeerPort PeerStatus
----------------------------------------------------------------------------
Stack-Port1/1 40GE1/0/1 up 40GE2/0/1 up
Stack-Port1/1 40GE1/0/2 down -- --
Stack-Port2/1 40GE2/0/1 up 40GE1/0/1 up
Stack-Port2/1 40GE2/0/2 down -- --
#
interface 40GE1/0/2
port mode stack
stack-port 1/1
port crc-statistics trigger error-down
device transceiver 40GBASE-COPPER
#
interface 40GE2/0/2
port mode stack
stack-port 2/1
port crc-statistics trigger error-down
device transceiver 40GBASE-COPPER
Please note below information .
2. Customer refer to the example used two link added to one Stack-port , but actually customer’s Stack topology connected to each other use one 40G port , so it need to change the configuration .
[~SwitchA] interface stack-port 1/1
[*SwitchA-Stack-Port1/1] port member-group interface 40ge 1/0/1
Warning: After the configuration is complete,
1.The interface(s) (10GE1/0/1-1/0/4) will be converted to stack mode and be configured with the port crc-statistics trigger error-down command if the configuration does not exist.
2.The interface(s) may go Error-Down (crc-statistics) because there is no shutdown configuration on the interfaces.Continue? [Y/N]: y
[*SwitchA-Stack-Port1/1] quit
[*SwitchA] interface stack-port 1/2
[*SwitchA-Stack-Port1/2] port member-group interface 40ge 1/0/2
[*SwitchA-Stack-Port1/2] quit
[*SwitchA] commit
[~SwitchA] quit
[~SwitchB] interface stack-port 1/1
[*SwitchB-Stack-Port1/1] port member-group interface 40ge 1/0/1
Warning: After the configuration is complete,
1.The interface(s) (10GE1/0/1-1/0/4) will be converted to stack mode and be configured with the port crc-statistics trigger error-down command if the configuration does not exist.
2.The interface(s) may go Error-Down (crc-statistics) because there is no shutdown configuration on the interfaces.Continue? [Y/N]: y
[*SwitchB-Stack-Port1/1] quit
[*SwitchB] interface stack-port 1/2
[*SwitchB-Stack-Port1/2] port member-group interface 40ge 1/0/2
[*SwitchB-Stack-Port1/2] quit
[*SwitchB] commit
[~SwitchB] quit
[~SwitchC] interface stack-port 1/1
[*SwitchC-Stack-Port1/1] port member-group interface 40ge 1/0/1
Warning: After the configuration is complete,
1.The interface(s) (10GE1/0/1-1/0/4) will be converted to stack mode and be configured with the port crc-statistics trigger error-down command if the configuration does not exist.
2.The interface(s) may go Error-Down (crc-statistics) because there is no shutdown configuration on the interfaces.Continue? [Y/N]: y
[*SwitchC-Stack-Port1/1] quit
[*SwitchC] interface stack-port 1/2
[*SwitchC-Stack-Port1/2] port member-group interface 40ge 1/0/2
[*SwitchC-Stack-Port1/2] quit
[*SwitchC] commit
[~SwitchC] quit
Root Cause：
Customer want to use Ring Stack Topology , but added all connnected Stack interface to one Stack-Port .
Solution：
Change the 40GE 1/0/2 to stack -port 1/2 , then commit the configuration and reboot the device from Master and backup and Slave .
Note : For ring topology stack , one port connect each other is not strong , if one link flapping , the whole Stack topology will recalculation .
