Fundamental solution to the problem that dbconsole cannot be started (EM cannot be used) after the IP address is changed (zz)

The fundamental solution (original) to the problem that the dbconsole service cannot be started (the EM cannot be used) after the IP address is changed)

I am a beginner in Oracle. I found a problem after installing Oracle a few days ago: I disconnected Oracle installed on the network cable and can be used normally, however, when I plug in the network cable, I find that the Oracle dbconsole service cannot be started. Enter
Set oracle_sid = orcl
Emctl start dbconsole
The following message is displayed: *
The reason is:
During installation, the directory oc4j_dbconsole_127.0.0.20.orcl is in the D: \ oracle \ product10.2.0 \ db_1/Solaris/J2EE/directory, but the IP address is 192.168.1.101 after the network cable is plugged in. Therefore, the file cannot be found. Run the command
Set oracle_hostname = 127.0.0.1
Emctl start dbconsole
It can be started slowly, but when it is started, it prompts that "service-specific error occurs: 2" cannot be started. I read some methods on the internet, basically there are some methods as follows:
1 (Classic) reconstruction em
SC Delete oracledbconsoleepcit
Emca-repos drop
Emca-repos create
Emca-config dbcontrol DB
Emctl start dbconsole
After the configuration, the problem should be solved. It is a bit esoteric for beginners. After the configuration, you may need to configure the listener address and so on. In fact, an oc4j_dbconsole_192.168.1.101_orcl folder is added.
2 (skill type)
If the folder cannot be found, copy an oc4j_dbconsole_127.0.0.20.orcl folder and change it to the oc4j_dbconsole_192.168.1.101_orcl folder. Note: You need to change the folder to either of the following.
This can also solve the problem.
3. Miscellaneous
However
The above methods are only temporary solutions. For example, after you configure em, you can plug in the network cable, but the disconnection is broken, and a prompt will be displayed.
Oc4j_dbconsole_127.0.0.20.orcl cannot be found. If a notebook is often taken to another place, you need to change the IP address frequently. Do you need to change the IP address frequently?
The method has the following hidden risks:
For example, when the IP address is a, I connect to Em through the folder and start some operations. Some changes may be made to the parameter file in the folder, and then
When the IP address is B, it is started through the B folder. In the past, when the IP address is a, the parameter is gone, because when the IP address is a and the IP address is B, two folders are set according to your method, when one of the operations is used, the corresponding file must be changed.
Without changing the other, you may not understand what you are talking about.
After a long time of searching and asking, I finally found the problem: Dynamic IP address and static IP address.

There will be a prerequisite check during Oracle installation, and the NIC option fails to pass the check (The problem may occur if the problem exists)// Indeed, this added by zhangjun

At that time, I did not take the case seriously. I just took the next step,
In fact, Microsoft loopback adapter is prompted during installation.
Configured as the primary network adapter of the system. After installation, the EM address becomes http: // 127.0.0.1: 1158/em.
, 127.0.0.1 is the default IP address of the computer. If the IP address changes, an error occurs. If Microsoft loopback adapter is installed
After installation, the EM address should be http: // host name: 1158/EM, so that the dbconsole service cannot be started because of IP changes,
The Microsoft loopback adapter installation process is as follows:
1. Control Panel -- add hardware -- select "yes, I have connected to this hardware. -- the last item is "Add new hardware device" -- "Install the hardware I manually selected from the class table" -- "network adapter" -- select the vendor as Microsoft mircosoft loopback adapter -- continue and complete
2. Modify the properties of the loopback adapter created in the network connection, set TCP/IP, and add an IP address, for example, 10.0.0.1, mask: 255.255.255.0, and leave the remaining value blank.
5. Recreate the EM Console

Run: emca. Bat-repos recreate
6. Start em Console

Run: emctl. bat start dbconsole
you may need to modify the listener address
so that your EM address will change to http: // host name: Port/EM, it will not change as the IP address changes.
if you can, install the Mircosoft loopback adapter and reinstall Oracle (note the following prerequisites) . You do not need to configure anything, otherwise, it will be messy, especially for a beginner.
// indeed, this added by zhangjun at
the whole process may not be quite clear. Check more information and hope it will be useful to you.