ora -01012 not logged on

[MUSTAFA ELSHIEKH]

Hi all,
I already read about this error, but i have a different situation, I am a DBA in a site that is already running fine and smooth, the next day this error is shown on 40% of the computers in the site, thinking it might be from thr TNS names but its not, and i checked the NLS_LANG and still not, i even thought it might be from the clients so i made image for getting sure from it, but still no solution. What is the possibility of having a virus in here, or if someone faced it before i will be thankfull for your helf.
Mustafa El-Shiekh.

[Mark Spritzler]

Have any users or passwords changed? Has anyone changed the URL mapping. Like for instance the server name. What do you call that, there is a file that maps IP addresses to server names so that it can be resolve. I don't remember the name of the file, but maybe someone changed that. Although you say only 40% of the machines have this problem, which would count those possibilities out, as everyone would have problems with them.
Maybe there are network connection problems for those users, like a switch or hub link down.
Hope that gives you some ideas.
Mark