Configuration of grid control agent 11g

Question

Hello guys,
I have problem with configuration of Grid control agent 11g. Root cause of the problem is that target machine is in DMZ Zone. So there is lack of ports enabled. Other agents I've been installed works properlly.
The one I am talking is able to upload data, but in case of configration I get error message: "Error occurred while getting information for the specified target. Possible reasons include: the target doesn't exist; connection to the target failed."
Here you are output from emctl status agent
Oracle Enterprise Manager 11g Release 1 Grid Control 11.1.0.1.0
Copyright (c) 1996, 2010 Oracle Corporation. All rights reserved.
Agent Version : 11.1.0.1.0
OMS Version : 11.1.0.1.0
Protocol Version : 11.1.0.0.0
Agent Home : /orahome/agent11g
Agent binaries : /orahome/agent11g
Agent Process ID : 3011
Parent Process ID : 2985
Agent URL : https://demodb:1830/emd/main/
Repository URL : https://admin:4900/em/upload
Started at : 2011-02-11 10:23:43
Started by user : oracle
Last Reload : 2011-02-11 10:39:40
Last successful upload : 2011-02-11 17:04:08
Total Megabytes of XML files uploaded so far : 20.98
Number of XML files pending upload : 0
Size of XML files pending upload(MB) : 0.00
Available disk space on upload filesystem : 14.21%
Last successful heartbeat to OMS : 2011-02-11 17:13:05
Agent is Running and Ready
emctl status oms -details
Oracle Enterprise Manager 11g Release 1 Grid Control
Copyright (c) 1996, 2010 Oracle Corporation. All rights reserved.
Enter Enterprise Manager Root (SYSMAN) Password :
Console Server Host : admin
HTTP Console Port : 7788
HTTPS Console Port : 7799
HTTP Upload Port : 4889
HTTPS Upload Port : 4900
OMS is not configured with SLB or virtual hostname
Agent Upload is locked.
OMS Console is locked.
Active CA ID: 1
Enabled ports:
from admin to demodb -1830
from demodb to admin - 4900, 4889
What else ports neeeds to be enabled? 1521..?
Thanks in advance!
Have a nice day

Answer 1

Thanks Lubiez Jean-Valentin! I think the point is here.
Configuring the Firewall to Allow Incoming Communication From the Management Service
While the Management Agents in your environment must upload data from your managed hosts to the Management Service, the Management Service must also communicate with the Management Agents. As a result, if the Management Agent is protected by a firewall, the Management Service must be able to contact the Management Agent through the firewall on the Management Agent port.
By default, the Enterprise Manager installation procedure assigns port 1830 to the Management Agent. However, if that port is occupied, the installation may assign an alternate port number.
After you determine the port number assigned to the Management Agent, you must then configure the firewall to allow incoming HTTP or HTTPS traffic (depending upon whether or not you have enabled Enterprise Manager Framework Security) on that port.
As I said already port 1830 was enabled. I did it because I saw that agent status - attached also here.
In case anybody know please tell me who to determine the port assigned to the Mangement Agent...