ERROR:ORA-12560: TNS:protocol adapter error + vmware linux issue

ERROR:ORA-12560: TNS: protocol adapter error


Senario:-

I have installed oracle in vmware RHEL-4 linux.I am able to ping the server but not able to login through command prompt.
I checked my tnsnames.ora and sqlnet.ora file was absolute fine.Even i create a oracle database in local machine and i was

able to connect to my local database,but i am not able to connect to that remote vmware machine database.

solution:-

open  the port 1521.As this port is disabled.I enable the port by entering below details.So that oracle able to connect.

vi /etc/sysconfig/iptables

-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 1521 -j ACCEPT

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