Daily Archives: April 19, 2016

Why Broadcast Packets Cannot Be Transmitted Successfully on Several HMSTP Data Boards?

Keywords: OptiX OSN 3500/7500/7500 II, ELAN, LAG, PW, UNI, MSTP

Summary:

When a physical port on a SSN1PEG8, SSN1PEX2, SSN2PEX1, TNN1EG8, TNN1EG16, or TNN1EX2 board

of the OptiX OSN 3500/7500/7500 II in a link aggregation group (LAG) is configured in an ELAN, and the

board has only one UNI and one PW interface in the ELAN, some broadcast packets cannot be transmitted

successfully in the ELAN.

 

[Problem Description]

Trigger conditions:

This fault occurs if the following three conditions are all met:

l The versions of SSN1PEG8, SSN1PEX2, SSN2PEX1, TNN1EG8, TNN1EG16, TNN1EX2 boards of OptiX

OSN 3500/7500/7500 II are involved in this pre-warning.

l A port of these data boards in a LAG is configured in an ELAN, and each board has only one UNI and one

PW interface in the ELAN.

l There are broadcast packets in the ELAN.

Fault symptoms:

Broadcast packets cannot be transmitted from the UNI to the PW interface, whereas unicast packets can be

transmitted from the UNI to the PW interface.

  • Identification method: Check whether the versions of the equipment are involved in this pre-warning.

 

OSN 3500

OSN 3500

 

  • Check for LAG configurations.

 

OSN 3500

OSN 3500

 

  •  Check whether the board in a LAG has only one UNI and one PW interface in one ELAN.

 

Note:

Network management personnel can check configurations of UNI interfaces and PW interfaces as shown

in the following figure.

 

 

OSN 3500

OSN 3500

  • Check whether broadcast packets cannot be transmitted from the UNI to the PW interface, whereas
  • unicast packets can be transmitted successfully from the UNI to the PW interface.

If the preceding four verifications are met, the board is faulty.

 

[Root Cause]

Due to software bugs of the SD8850 chips used in the OptiX OSN3500/7500/7500 II, when a port of these

data boards in a LAG is configured in an ELAN, the upstream broadcast packets from a UNI cannot be copied

to the board. Therefore if a PW interface and a UNI are on the same board, broadcast packets cannot be

transmitted from the UNI to the PW interface.

 

[Impact and Risk]

When the trigger conditions are met, broadcast packets cannot be transmitted successfully from the UNI to

the PW interface.

 

[Measure and Solutions]

Recovery measure:

Modify configurations so that the UNI and the PW interface are not on the same board.

Preventive measure:

Plan networking so that the UNI and the PW interface are not on the same board.

Solution:

Upgrade to V200R0013C00SPC100 or a later version.

 

[Inspector Applicable or Not]

Inspection case name:

Broadcast packets cannot be transmitted successfully on several HMSTP data boards

 

[Rectification Scope and Time Requirement]

N/A

 

[Rectification Instruction]

N/A

TwitterLinkedInGoogle+FacebookPinterestTumblrStumbleUponRedditShare