High packet loss verification on IvS
Article ID: 392251
Updated On:
Products
Issue/Introduction
Industrial vSwitch (IvS) can forward realtime application traffic with low latency. In addition to low latency, it is important to monitor packet loss, because high packet loss could cause application issues.
This article describes how to check the packet loss status on IvS.
Environment
4.2.x
Resolution
If you run the prp node command with an Dual Attached Device (DAN) node MAC address, it can show the detailed counters information related to PRP communication for LAN A and LAN B.
- Get the MAC address of the DAN that is connected Profinet network
- Login to the ESXi Host via SSH
- Run the command and find the DvsPortset name for the MAC address
net-stats -l
- Run the command and find Switch ID (swID) for the DvsPortset
nsxcli -c get ens switch list
- Run the command and show the PRP related packet counters
nsxcli -c get ens prp node <swID> <VLAN ID> <MAC ADDRESS>
[root@localhost:~] nsxcli -c get ens prp node <swID> <VLAN ID> <DAN MAC ADDRESS>
Fri Feb 21 2025 UTC 20:41:26.018
NodeIndex ######
Node MAC <DAN MAC ADDRESS>
Node VLANID <VLAN ID>
Node Type DAN
Associated vDAN MAC <vDAN MAC ADDRESS>
Red Box MAX <RedBox MAC ADDRESS>
Operation mode Duplicate_Discard
Last supervision seq from LANA 13287
Last supervision seq from LANB 13287
Last received seq from LANA 4339
Last received seq from LANB 4339
Number of Lcore move 0
Number vDAN change 0
Number of VLAN change 0
Current LcoreID 1
Last LANA supervision frame age(s) 1
Last LANB supervision frame age(s) 1
Last LANA received frame age(ms) 0
Last LANB received frame age(ms) 0
LANA
prpRxPkts 32772339
nonPRPRxPkts 0
rxBytes 2162975918
dupDrops 4982025
outOfOrderDrops 0
wrongLANDrops 0
supRxPkts 32927
LANB
prpRxPkts 32772339
nonPRPRxPkts 0
rxBytes 2162975918
dupDrops 27790314
outOfOrderDrops 0
wrongLANDrops 0
supRxPkts 32927
Node creation time Fri Feb 21 06:03:13 2025From this output, you can compare the prpRxPkts counters for LAN A with LAN B. If there is packets loss in LAN A or LAN B, it will show the different number, and you can understand which LAN is having packet loss issue.
If the outOfOrderDrops is increasing, it means that IvS is receiving packets in wrong order. This could be caused by the LAN A or LAN B network. Check switches/routers and links are desinged and configured correctly.
If the wrongLANDrops is incresing, DAN or RedBox is sending packets with wrong LAN name. It is recommeded to check the configurations on DAN/RedBox devices.
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