vCenter looses network

[rimvydukas]

Hi,

I have very mystical problem, maybe someone will help me. Here is my situation. I have vCenter 5.5 U3 server on 2008 R2 VM. vCenter's SQL database is on physical server. Recently I noticed that vSpehe windows client started to loose connection with vcenter server for a few minutes then it was able to reconnect to vcenter server again. I started to troubleshoot and found very interesting thing - when connection with vcenter is lost I still can work with the windows server itself via RDP, but only ping works from this server to the outside. I can see that vcenter is communicating with SQL via wireshark, but telnet to 1433 port doesn't work:/ What is more - no telnet communications to other servers and to any port, even in the same subnet, work:/ When vsphere client is able to reconnect to vcenter server - telnet connections start to work:/ So I need some advice where to search for a problem. It seems that this problem is like some kind of tcp connections limit to me:/

[IT_pilot]

Question with the updates of Windows are excluded? All checked?

[rimvydukas]

I do not understand the question. Could you clarify?

[IT_pilot]

Very often the Windows operating system does not work correctly with updates.

For example, when updates are waiting for the installation. Or when updates are not installed correctly. Or the problem is in the updates themselves.

Often you have to roll back the updates to restore functionality. Therefore, for any problems in the operation of applications, it is necessary to check whether they are connected with patches.

[rimvydukas]

Yes, the server is connected with internal WSUS, but I strongly doubt that the problem is related to updates. As I said before - when I have problems with vcenter only ping works from this windows machine to different servers. But I can't access any other ports on remote servers even if these servers are in the same subnet:/ After one minute everything starts to work again and I'm able to access remote ports on remote servers via telnet. So I don't know where to dig:/ windows server logs are clear from errors. It has no update installed recently.

[rimvydukas]

And it seems that the problem is somehow related to guest introspection machine which is running on the same ESXi. I use it only for vshield endpoint functionality but it seems that guest introspection somehow mess my VM network:/ I stopped guest introspection machine and now I'm not able to see network problems on the problematic VM. Now I need to find a reason of these problems.