Severe latency due to Unicast Probe & VDR Hold Queue Issue
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Article ID: 317182
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Updated On:
Products
VMware NSX
Issue/Introduction
Users experience severe latency when browsing.
Pick a couple of hosts that have Server and Client VMs deployed and execute the below command
net-vdr -I -l
In the output look for the value with the arrow next to it. If it's 1000, use this host for running tests.
Example output
== [root@localhost:~] net-vdr -I -l DR Instance Information : --------------------------- DR UUID: 2478a1e5-####-####-####-6ea3a0176f84 DR Id: 0x00000002 Number of Lifs: 3 Number of Routes: 4 Number of Hold Pkts: 1 <======== State: Enabled Num unique nexthops: 1 Number of ARP Entries: 18 Max number of ARP Entries: 50000 Generation Number: 0 Edge Active: No Pmac: 00:00:00:00:00:00 Dynamic resource pool tag: 65535 Multicast Routing: Disabled ==
Execute the below command to find out LIF that has more Nascent ARPs. Note the UUID from the last column in the output.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ created a vdr-neighbor-entries.txt file for all hosts with the 1000 Hold Packets (with the hostname in front) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Confirm the issue by identifying the hostnames with the 1000 Hold Packets less vdr-neighbor-entries.txt after running above command or net-vdr -N -l <DR-UUID>
Environment
VMware NSX-T Data Center 3.x
Cause
‘Number of Hold Packets’ counter never decrements. Unicast ND probe not working.
Resolution
This issue is resolved in VMware NSX 3.2.0, available at Broadcom downloads.