I installed Oracle 10gR2 on Linux machine (CentOS Release 5). This
machine uses DHCP protocol.

I can't use EM from my PC to connect to the database.

I made sure that the Entrprise Manager is up and running on the Linux
machine.

emctl status dbconsole

TZ set to US/Eastern
Oracle Enterprise Manager 10g Database Control Release 10.2.0.1.0
Copyright (c) 1996, 2005 Oracle Corporation. All rights reserved.
Oracle Enterprise Manager 10g is running.

Dropped and recreated EM repository using emca deconfig/config
commands.

Unlocked the syman account.

Edited the entries in emoms.properties for the encrypted password.

Stopped and restarted EM using emctl start/stop dbconsole command.

But still the EM can't connect to the DB.

I understand that this problem could be DHCP related. If so, is there
a work-around?

Also, I can not connect to the DB on the Linux machine using PL/SQL
developer on my PC. I get ORA-12560 TNS Protocol adapter error.

I made sure that the entry in my tnsnames.ora file on the PC is same
as the one in the tnsnames.ora file on the Linux machine. On Linux
machine, I can connect to the DB using SQLPlus.

I stopped and restarted the listener on the linix machine.

What else should I check?

Thanks in advance.

On Jan 31, 10:34*am, Ora_DBA <sanjaydharmadhik... (AT) gmail (DOT) com> wrote:
I also made sure that the ports on the linux machine ( 1158 and 1521 )
are open.

When I use TNSPing command from my PC, it returns an error.

C:\Documents and Settings\sdharmadhik2>tnsping asndb

TNS Ping Utility for 32-bit Windows: Version 10.2.0.1.0 - Production
on 31-JAN-
009 10:52:18

Copyright (c) 1997, 2005, Oracle. All rights reserved.

Used parameter files:
C:\oracle\product\10.2.0\db_1\network\admin\sqlnet .ora


Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST
= EBEST-1.
wbc.csi.com)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED)
(SERVICE_NA
E = asndb)))
TNS-12560: TNSrotocol adapter error

Ora_DBA schreef:
Don't use DHCP, or configure a virtual fixed ip-address on your network
device and install using that address by putting it on top in your
host-file.

Shakespeare

Shakespeare wrote:
Agreed. DHCP is for clients - if you NEED to know where your box is (ie
a server!) - use a static address on your local net. If you are going to
be a decent DBA, you really need to understand all aspects of a system -
that includes the system/cpu/memory usage and configuration, SAN,
network AND database layers. And then - you will need to also understand
(to some degree at least) the application and how it uses the database.

On Jan 31, 8:54*pm, Ora_DBA <sanjaydharmadhik... (AT) gmail (DOT) com> wrote:

if you are sure that the EM server is listening, make sure the clients
can connect to the ports on the server too. use the command: "telnet
<SERVER_IP_OR_NODE_NAME> <PORT_NUMBER> " to see if you are able to
connect from the client. check your sqlnet file to see if there is any
domain name restriction set in your installation. check if the
tnsnames.ora has the correct SID that matches the GLOBAL_DBNAME in the
listener.ora file on the server.

let us know what you find out!

On Feb 1, 3:39*am, yanamandra <venu.yanaman... (AT) gmail (DOT) com> wrote:
Tried to connect to the port using telnet. It failed.

No domain name restrictions in the sqlnet.ora file.

SID in the tnsnames.ora mataches GLOBAL_DBNAME in the listener.ora
file.

Thanks.

On Jan 31, 9:25*pm, Michael Austin <maus... (AT) firstdbasource (DOT) com> wrote:
I will do that.

Thanks.

On Feb 1, 7:20*pm, Ora_DBA <sanjaydharmadhik... (AT) gmail (DOT) com> wrote:
login to the server box and perform the telnet operation there. If it
does not connect then the service is not started. Else, it could be a
firewall (either on the Linux box or the Windows box) that is
preventing this connect operation. to disable the firewall temporarily
on the linux box do this: type "setup" on the command prompt as the
root user. Go to 'firewall configuration' and select disabled. Now,
restart the network on that box using: "service network restart". try
again from the windows box. also, disable the firewall on the windows
box or add the port exception to your firewall.

another good command to help you verify that the port is open or not
is: "netstat -a | grep <PORTNUMBER>" on the server box.

hope this helps.


this way we can be sure that the outside world is able to communicate
to this box.

On Feb 1, 9:47*am, yanamandra <venu.yanaman... (AT) gmail (DOT) com> wrote:
Thanks. I will have to ask Linux Admin to do that. Will let you know
the result.

On Feb 1, 9:47*am, yanamandra <venu.yanaman... (AT) gmail (DOT) com> wrote:
Yes it was due to the firewall. The ports have been opened and EM and
PL/SQL developer can now connect to the DB.

Thank you everybody.