OCI - Intermittent Network Drops (Doc ID 2735290.1)

Last updated on AUGUST 17, 2023

Applies to:

Linux OS - Version Oracle Linux 7.0 and later
Information in this document applies to any platform.
x86_64

OCI Instance shows intermittent network drop.
Existing connections are fine and working on full bandwidth.
When the issue is surface, it will not connect to new connection intermittently.
For example, a new ssh session or a new iperf session etc.
The only work around at that time is to reboot the instance

Setup tcpdump on the instance which got the issue, run the same tcpdump on hypervisor where this guest is hosted and one on the good machine
Start iperf in server mode on the host with this issue, and run iperf client from the good machine.
When issue hits new connection to the iperf server will hung and will not connect intermittently.
At that time, the tcpdump till the Hypervisor will show the packets and after that there won't be any information.
It will appear as the packets are getting dropped between Hypervisor and the Guest.
Same way the " # ip -s -s -s -d link "on the affected guest will not show any drops.
But # netstat -s | grep -i pfmem on affected machine shows increase in counted when there is an issue happening.