Hi Pupul, today I found the answer for this problem but it is a little bit strange. At first: this both servers are a high critical system. I avoid it to reboot one of them outside the official maintenance hours if I can. Yesterday in the afternoon I detected that the server adserv196 has strange errors while I tried to install the new diag software. I decided that a reboot was the only clean way to clear this. I have done this today in the morning. What then happens was following: The server could not start because it was not able to initialize the iDRAC. Shut off and on of the server don't helped. I must pull the power cables to make the complete machine powerless for 10 sec to reset the iDRAC. After this the server started without errors. The iDRAC is online again. And the error with the NLB-MAC disappears. Now OME can discover and initialize both servers again. It seems that the hanging iDRAC causes the problem. I had hanging iDRACs before but never seen such problem. And why this became visible only after the discovery after loading a new catalog stays a secret. Thank you for your effort. I hope this can help somebody with a similar problem. Greetings Barbara 
I use OME 2.1.0.2635. Since two days I have a problem with the discovery and inventory of two servers which are an NLB cluster. OME detects the MAC of the NLB as MAC of the servers and interpret this so that there is one server where the name changed. See attachment. It is not possible to mange both servers with OME. The Servers are 2008 R2 Std. with OMSA 8.2.0. The NLB has dedicated NICs so I don't understand how an why OME detect the NLB instead the servers itself. I configure the discovery range with the IP addresses of the servers so there should be no hint for OME that there is more than this. This configuration function several month. The update to OMSA 8.2 was made before some weeks. Greetings Barbara 
2 Nodes of NLB Cluster will detected as 1 Server