This topic describes how to troubleshoot the fault when Huawei OLT fails to interconnect
with the switch of another vendor due to incorrect Link Aggregation Control Protocol (LACP)
configuration on the switch.
Fault Description
The OLT is connected to a certain type of switch of another vendor in the lacp-static aggregation
mode in the upstream direction. After lacp-static is configured, an alarm is generated, and the
related service is unavailable.
Alarm Information
The alarm generated on the OLT is as follows:
huawei(config)#link-aggregation 0/17 0-1 egress-ingress workmode lacp-static huawei(config)# ! EVENT MAJOR 2008-07-15 13:42:03 ALARM NAME :Port is forbidden to transfer the service packets PARAMETERS :FrameID: 0, SlotID: 17, PortID: 0 huawei(config)# ! EVENT MAJOR 2008-07-15 13:42:03 ALARM NAME :Port is forbidden to transfer the service packets PARAMETERS :FrameID: 0, SlotID: 17, PortID: 1
Cause Analysis
- The upstream optical path of the OLT is faulty.
- The data configuration of the upstream port on the OLT is incorrect.
- The LACP configuration is incorrect.
- The configuration of the peer switch of this vendor is incorrect.
Procedure
Check the configuration of the upstream board on the OLT and the configuration of
the switch. It is found that the interconnected optical ports on the OLT and the
switch are configured as forced 1000 Mbit/s and full duplex, and are in the up state.
Therefore, it can be determined that the fault is not caused by the optical path.
Disable the aggregation function. It is found that the upstream service of a single
link is normal. Therefore, it can be determined that the data configuration of the
upstream port on the OLT is correct.Configure the aggregation manually, and do
not run the LACP protocol. It is found that the services are normal. Therefore,
it can be determined that the fault is caused by the LACP interconnection.
NOTE:
- The systems at both ends of the link of the static LACP aggregation group run the
LACP protocol; however, systems at both ends of the link of the manual aggregation
group do not run the LACP protocol.
2. The switch of this vendor supports both the Port Aggregation Control Protocol (PAgP)
and LACP, and uses PAgP by default. It is preliminarily suspected that the default protocol
PAgP runs on the switch, which causes interconnection failure. After check, however, it is
found that LACP runs on the switch.
3. Configure the switch to be in the active LACP mode. The fault then is rectified.
Suggestion and Summary
The switch of this vendor supports the following two LACP modes:
Passive LACP mode (default mode): In this mode, the port is in the passive state, and does
not initiate an LACP negotiation.
Active LACP mode: In this mode, the port is in the active state, and initiates an LACP negotiation.
In this case, the LACP mode is configured on the switch, but an active negotiation is not initiated,
which causes the failure to interconnect with Huawei OLT.
Suggestion: When the LACP mode of the Huawei OLT is set to active LACP (default mode) and the
OLT is connected to the switch of another vendor in the upstream direction after link aggregation:
If the switch of another vendor does not comply with the LACP, this switch must be configured with
the active LACP mode.
If the switch of another vendor complies with the LACP, the LACP negotiation can be initiated regardless
of whether this switch is configured with passive LACP mode or active LACP mode.
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