ORA-12170: TNS:Connect timeout occurred

Question

I was trying to connect to the database here in my laptop using Oracle Toad but I kept on having this error:

ORA-12170: TNS:Connect timeout occurred

What are the possible reasons why I kept on having this error?

I accessed the same database yesterday and was able to accessed it.

Answer 1

open sqlnet.ora  

NAMES.DIRECTORY_PATH= (TNSNAMES, EZCONNECT)
SQLNET.INBOUND_CONNECT_TIMEOUT=360
SQLNET.RECV_TIMEOUT=10
SQLNET.SEND_TIMEOUT=10

http://docs.oracle.com/cd/B19306_01/network.102/b14213/sqlnet.htm