[Fix]-ORA-12170 error occurred-connection problem
ORA-12170 connection timeout occurred.
Connecting to oracle 10g db through TOAD installed on another machine.
This could be due to DNS resolution problems. Try the command dnslookup <hostname> to check for DNS resolution status.
The listener port is different than that of the configured. Standard port value is 1521.
Sometime the firewall can block from accessing the database. Try performing the connections with TOAD on the same machine and if it works, adjust the firewall.
Check for the database listener and activate it.