Moved to Software Defined Networking and seeing dropped connections from Master to VM clients
Good Afternoon All,
A little background our Virtual infrastructure and backup environment are in SDN (CISCO Application Centric Infrastucture, Software defined Networking). We have a development and corporate VM's. The Network admins have noticed that there are thousands of dropped connections to the development from the master server attempting to connect to 1556 and 13724. This has puzzled me as all of these clients are backed up using VIP's none of them have the NetBackup client installed on them. Is this behavior by design or is this something I can turn off. Sadly ACI drops the packets silently with this in mind we are at the mercy of TCP connections timing out gracefully using the OS default timeouts. This is compounded by the fact that the development environment has a circa 2000 clients. The development environment is segregated from the rest of the network and we are only allowed to get to them through the Virtual Centers. We do not see this behavior for the corporate servers, they are VM's too but some VM's have NetBackup clients installed on a case by case basis and the ACI contracts allow these ports to the clients. Any advice will be greatly received.
I suspect what you are seeing is a known issue with OpsCenter which is looking to intererogate all known clients via the master server. If this is the case there is a EEB available for this - log a support call and reference ET3983346 (assuming you are on 8.1.2, or ET3980658 for 8.2).
You should be able to test this theory by disabling OpsCenter for a period and observe whether you see the suprious connections. If you don't have OpsCenter installed and monitoring the environment, then I'm not sure what it could be.
I first saw this back in Dec 2019 with a new NetBackup customer (predominantly VMware) who was wondering exactly the same as you.
Hope this helps
David