Oracle Database Discussions

Hi,

I am experiencing problems connecting to my local oracle db using the sqlplus command tool.
I have created the necessary settings as described into the documentation and I am able to connect to the db with external tools (sqldeveloper, net manager, net configuration assistant - test) but when I try to do the following:

sqlplus system/password@prem

I receive the following error message:

ORA-12154: TNS:could not resolve the connect identifier specified

My service name is prem.ucb.lan, my connect identifier is prem, I use the TNSNAMES for local naming. I've been struggling for days around this problem now and it seems that there isn't much information on the net regarding how to debug this issue. Everything points to "possible incorrect tnsnames.ora" but I am pretty sure that mine is OK.

Any ideas?