TCP reassembly queue overflows lead to poor performance and possible application disruption in versions of ONTAP 9.3, 9.4 and 9.5
Applies to
- ONTAP 9.5
- ONTAP 9.4
- ONTAP 9.3
Issue
A security vulnerability fix in the ONTAP networking stack causes Transmission Control Protocol (TCP) performance to unexpectedly degrade.
Signature
- On an applicable version (ONTAP 9.3P9-P11, 9.4P3-P6, 9.5-9.5P2)
- Refer to KB TCP Reassembly Queue Overflows Lead to Poor Performance and Possible Application Disruption on 8.2.5P2 7-mode or ONTAP 9.1P16, if on 7-mode 8.2.5P2 or ONTAP 9.1P16
- TCP slowness
- Network is not lossless
- Indications that the TCP reassembly is being overran can be seen via ‘
netstat -s -p tcp’
Command: node run -node <node> netstat -s -p tcp
Counter: <no. packets> discarded due to memory problems