Comware

Hi, 

Seeing this type of syslog message in the logbuffer of several HPE-5140-Hi and HP-5140-EI switches and stacks

%%10DRVPLAT/4/SOFTCAR DROP: -DevIP=172.27.7.13;  PktType=ARP, SrcMAC=303f-bb35-d759, Dropped from interface=Ten-GigabitEthernet1/0/49 at Stage=0, StageCnt=144, TotalCnt=538, MaxRateInterface=Ten-GigabitEthernet1/0/49.

Trying to understand what the message is telling us and what is triggering it 

I suspect it has something to do with a spanning-tree topology change notification , because we generally see these stp TCN messages in the syslog buffer around the same time

10STP/6/STP_DETECTED_TC Instance 0's port GigabitEthernet2/0/4 detected a topology change.

Reason we're investigating the syslogs is because clients connected to HPE-5140 stacks experienced a network outage recently and we could not determine the root cause. The network outage was resolved by rebooting the HPE-5140 stack 

Any help or pointers would be appreciated 

The HPE-5140-stacks are on the latest recommended firmware  

Hi, do the 5140 HI and the 5140 EI on their Comware levels provide the display packet-drop interface (specifying an interface like the GigabitEthernet 1/0/49, as example) and the display packet-drop summary (for all interfaces) commands to help you investigate further any possible relationship with traffic congestion or with the STP?

Notes:
Packets dropped due to full GBP or insufficient bandwidth = Packets that are dropped because the buffer is used up or the bandwidth is insufficient.
Packets dropped due to Fast Filter Processor (FFP) = Packets that are filtered out.
Packets dropped due to STP non-forwarding state = Packets that are dropped because STP is in the non-forwarding state.

Hi, 

Thanks a lot for reading my post and replying. Your explanation is very good. When I run those commands on the 5140-Stack , it says "The operation is not supported"  ? 

[MPD-69-ECCLES-5140-STACK]
[MPD-69-ECCLES-5140-STACK]display packet-drop interface Ten-GigabitEthernet 1/0/49
The operation is not supported.
[MPD-69-ECCLES-5140-STACK]
[MPD-69-ECCLES-5140-STACK]
[MPD-69-ECCLES-5140-STACK]display packet-drop summary 
The operation is not supported.
[MPD-69-ECCLES-5140-STACK]

I think it's highly likely that the dropped packet message is due to STP going non-forwarding on the Ten-gig 1/0/49, which is one of the 2 X 1GB fibre uplinks in a bridge-aggregation group. None of the interfaces are overutilized, most of the graphs tell us they rarely go over 50MB bandwidth  

Whenever we see that 10DRVPLAT/4/SOFTCAR DROP: in the logbuffer, there is generally a STP TCN (topology change notification message) around that time. 

The LAN has a 5900 CORE-Switch that is configured as the rstp root bridge (priority 0) and all the switches in the infrastructure run rstp 

Whenever an uplink between CORE-Sw and another access-stack goes down/up, that generates an RSTP TCN sent throughout the LAN infrastructure. 

My hope was that these occaisonal rstp TCNs do not cause the network to stop forwarding ?? 

Packets dropped due to STP non-forwarding state = Packets that are dropped because STP is in the non-forwarding state.