No relevant resource is found in the selected language.

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Read our privacy policy>

Reminder

To have a better experience, please upgrade your IE browser.

upgrade

Services on OLT Are Interrupted During Cutover for Optical Link on a Member Interface of Eth-Trunk in Static LACP Mode

Publication Date:  2013-09-03 Views:  20 Downloads:  0
Issue Description

1. ME60 version:
V600R002C02SPC700+V600R002SPC031

2. Networking:
ME60-1 connects to OLT1 through Eth-Trunk 17 (member interfaces g10/7 and g2/0/7).
ME60-2 connects to OLT2 through Eth-Trunk 16 (member interfaces g10/7 and g2/0/7).
The Eth-Trunks work in static LACP mode.
http://3ms.huawei.com/icase/servlet/download?dlType=HtmlAreaImage&imageId=20512

3. Symptom:
1. Remove the optical fiber from g2/0/7 on ME60-1. A member down alarm is generated on Eth-Trunk 17 is Down, indicating that 18/0 on OLT1 is Down.
2. Remove the optical fiber from g2/0/7 on ME60-2. A member down alarm is generated on Eth-Trunk 16 is Down, indicating that 18/0 on OLT2 is Down.
3. Mistakenly connect 18/0 on OLT1 to g2/0/1 on ME60-2 through an optical fiber.
4. Eth-Trunk 17 on ME60-1 is disconnected and services on OLT1 are interrupted. Eth-Trunk 16 on ME60-2 is normal and services on OLT2 are normal
http://3ms.huawei.com/icase/servlet/download?dlType=HtmlAreaImage&imageId=20513

2012/7/20 15:33:18 Remove the optical fiber from g2/0/7 on ME60-1. A member down alarm is generated on Eth-Trunk 17, indicating that 18/0 on OLT1 is Down.
"ZJWZ-MC-CMNET-RT007-YJ_ME60_1 %%01PHY/4/PHY_STATUS_UP2DOWN(l)[1325264]:Slot=2;GigabitEthernet2/0/7 change status to down.
ZJWZ-MC-CMNET-RT007-YJ_ME60_1 %%01Trunk/5/MEMBER_DOWN(l)[1325265]:Slot=2;The status of the trunk member went Down. (TrunkName=Eth-Trunk17, PortName=GigabitEthernet2/0/7)"


2012/7/20 15:35:02 Remove the optical fiber from g2/0/7 on ME60-2. A member down alarm is generated on Eth-Trunk 16, indicating that 18/0 on OLT2 is Down.
"ZJWZ-MC-CMNET-RT008-YJ_ME60_2 %%01PHY/4/PHY_STATUS_UP2DOWN(l)[1233419]:Slot=2;GigabitEthernet2/0/7 change status to down.
ZJWZ-MC-CMNET-RT008-YJ_ME60_2 %%01Trunk/5/MEMBER_DOWN(l)[1233409]:The status of the trunk member went Down. (TrunkName=Eth-Trunk16, PortName=GigabitEthernet2/0/7)"

2012/7/20 15:49:43 Mistakenly connect 18/0 on OLT1 to g2/0/7 on ME60-2. The ports go Up.
"ZJWZ-MC-CMNET-RT008-YJ_ME60_2 Slot=2;GigabitEthernet2/0/7 change status to up."

2012/7/20 15:49:53 Eth-Trunk 16 on ME60-1 is disconnected and OLT1 gets offline. OLT2 is not faulty.
"ZJWZ-MC-CMNET-RT007-YJ_ME60_1 The status of interface Eth-Trunk17 turns Down.
Handling Process

Log in to ME60-1 and check status of Eth-Trunk 17. Eth-Trunk 17 is in Unselected state, the physical status of g1/0/7 is Up, and the physical status of g2/0/7 is Down.
The customer has replaced the fiber jumper because the original optical link was faulty on g2/0/7 of ME60-1.
Check the optical link onsite and remotely. The result shows that the optical fiber to g2/0/7 on ME60-1 was mistakenly connected to g2/0/7 on ME60-2, leading to service interruption on OLT1.  

1. LACP comparison
a. Compare the system priority of the devices on the network. If their system priorities are the same, compare their MAC addresses.
b. The device with the highest priority selects a port for preferential LACP negotiation.
c. If the ports have the same priorities, the port is selected based on port numbers.
A small value indicates a higher priority.
Check the Eth-Trunk status on ME60 devices. The system priorities of the four devices are all 32768. ME60-2 with the smallest MAC address has the highest LACP priority. Therefore, link aggregation on the Eth-Trunk in LACP mode is preferentially performed on ME60-2.

<ZJWZ-MC-CMNET-RT007-YJ_ ME60_1>display eth-trunk 17
Eth-Trunk17's state information is:

Local:
LAG ID: 17                  WorkingMode: STATIC                              
Preempt Delay:
Disabled     Hash arithmetic: According to flow                
System Priority:
32768      System ID: 286e-d4ac-aec8                        
Least Active-linknumber:
1  Max Active-linknumber: 17                        
Operate status:
up          Number Of Up Port In Trunk: 2                    
--------------------------------------------------------------------------------
ActorPortName          Status   PortType PortPri PortNo PortKey PortState Weight
GigabitEthernet1/0/7   Selected 1GE      32768   263    4145    11111100  1    
GigabitEthernet2/0/7   Selected 1GE      32768   519    4145    11111100  1    

Partner:

--------------------------------------------------------------------------------
ActorPortName          SysPri    SystemID  PortPri PortNo  PortKey   PortState
GigabitEthernet1/0/7   32768  781d-ba7b-16dc  16384  97    1         11111100
GigabitEthernet2/0/7   32768  781d-ba7b-16dc  16384  99    1         11111100

<ZJWZ-MC-CMNET-RT008-YJ_ ME60_2>display  eth-trunk  16
Eth-Trunk16's state information is:

Local:
LAG ID: 16                 WorkingMode: STATIC                              
Preempt Delay:
Disabled     Hash arithmetic: According to flow                
System Priority:
32768      System ID: 0025-9ebc-6799                        
Least Active-linknumber:
1  Max Active-linknumber: 16                        
Operate status:
up          Number Of Up Port In Trunk: 2                    
--------------------------------------------------------------------------------
ActorPortName          Status   PortType PortPri PortNo PortKey PortState Weight
GigabitEthernet2/0/7   Selected 1GE      32768   519    4401    11111100  1    
GigabitEthernet1/0/7   Selected 1GE      32768   263    4401    11111100  1    

Partner:

--------------------------------------------------------------------------------
ActorPortName          SysPri    SystemID  PortPri PortNo  PortKey   PortState
GigabitEthernet2/0/7   32768  781d-bab0-5306  16384  99    1         11111100
GigabitEthernet1/0/7   32768  781d-bab0-5306  16384  97    1         11111100

2. LACP negotiation upon incorrect optical fiber connections
a. Two member interfaces exist on ME60-2. The port for LACP negotiation is selected based on port numbers. g1/0/7 with the smallest port number has the highest priority.
The member interface g1/0/7 on ME60-2 is selected for LACP negotiation and succeeds in negotiating with 17/0 on OLT2. Therefore, services on OLT2 are normal.
2. System ID in LACP packets received on g2/0/7 of ME60-2 is different from that on g1/0/7, so g2/0/7 is not selected.
Therefore, the link between g2/0/7 on ME60-2 and OLT1 is not selected.
3. When the member interfaces on OLT1 receive LACP packets from ME60-1 and ME60-2, OLT1 preferentially initiates negotiation with ME60-2 because ME60-2 has the higher system priority. The link between OLT1 and ME60-1 fails to be successfully negotiated, leading to service interruption on OLT1.
Root Cause
Fiber jumpers are incorrectly connected.
Solution
Correctly connect fiber jumpers. Services on OLT1 are recovered.
Suggestions
1 Summary
LACP is flexible. OLT1 is incorrectly connected to g2/0/7 of ME60-2. In this case, LACP uses ME60-2 for negotiation, but g1/0/7 of ME60-2 is used for negotiation.
The only method is to change the system and interface priorities. However, we cannot determine which link is faulty.

2 Precaution measure
1. Before performing operations for fiber jumpers, correctly perform LACP negotiation on the link where operations for fiber jumpers are not required by adjusting the system and interface priorities.
2. Correctly connect fiber jumpers.

3 Solution
1. Adjust system and interface priorities so that devices perform LACP negotiation through the link in Up state to restore services.
2. Correctly change the positions of fiber jumpers.

END