I am getting the following error when effecting consultations saw database link :
SQL> select sysdate from dual@grp3;
select sysdate from dual@grp3
*
ERRO na linha 1:
ORA-12545: Connect failed because target host or object does not exist


SQL> select sysdate from dual@grp3;

SYSDATE
--------
25/07/07

SQL>

I made the two consultations with difference of some seconds. Somebody has a tip?