Starting Oracle Database Enterprise Manager

1. Switch user to root
    su root
     or
    sudo su

2. Set ORACLE_SID
    ORACLE_SID = ORCL
    export ORACLE_SID

3. Set ORACLE_HOSTNAME
    ORACLE_HOSTNAME= localhost
    export ORACLE_HOSTNAME

4. emctl start dbconsole

    emctl is available in bin folder in Oracle  installation folder
    oracle/product/11.2.0/dbhome_1/bin

5. Access oracle enterprise manager using the URL: https://localhost:1158/em

Upgrade Firmware of Router With DD-WRT for Super Performance

1. Upgrading Firmware of  a Cisco Linksys Router WRT160N V3

All the digital devices come with firmware that power their functionality. Similarly, our routers come with a firmware provided by the manufacturer which promises a standard performance. This may not be satisfactory for most of us. The router can be upgraded with open-source firmware to unleash its hidden power and features.  DD-WRT is an open-source alternative firmware for routers. Its software unlocks features and settings that aren’t accessible normally. Here are the steps to upgrade Cisco Linksys Router WRT160N V3 with DD-WRT firmware:

1. Find the make and model of your router

    Make : The manufacturer and the router name. Here the manufacturer is "Cisco" and Router name is "Linksys".

    Model : It is found at the bottom panel of the router. Here the model number is "WRT160N V3".

   See the technical specification of the router to find the flash size which is 4MB.

2. Search for the model WRT160N  in DD-WRT database and select the revision V3. This confirms that the  router is supported by DD-WRT.

3. Download the firmware "NEWD K2.6 Mini Generic".

 
 
   Note:  To download the most recent build, use ftp://dd-wrt.com/others/eko/V24-K26/.  Download the file with wrt160nv3 in the file name. 

4. Perform 30/30/30 reset of the router using following steps
    a) Reset button is at the back of the router along with the ethernet cable ports and the power point.
    b) Press the resent button for 30 seconds with the power cord plugged in.
    c) With the resent button still pressed, remove the power cord, and  keep the reset button pressed  for 30 more seconds.
    d) With the resent button still pressed, plug in the power cord. Led lights on the front panel of the router blinks. Keep the reset button pressed till all the lights blink for the second time. Just after the blink, release the reset button. Let the router reboot. Once the router is rebooted, we can see the wireless light glowing.
5. Switch off the wireless adapter of your laptop and all other laptops connected to the router.
6. Connect your router with the laptop using an ethernet cable.
7. Navigate to http://192.168.1.1/ in a browser. Use username: admin and password: admin or username: root and password : admin to get the basic-setup page of Cisco Linksys.
8. Navigate to Management tab -> Upgrade Firmware tab.
9. Choose the firmware file and upload it.
10. Upon successful completion of the upload, we will redirected to a page with the message that the upgrade is successful. Keep the page as it is.
11. Again reset the router as in step 4.
12. Go to the page in step 10 and click continue. We should be at a new page "dd-wrt.com control panel".

Note: If it does not work, again navigate to http://192.168.1.1/ in a browser. We should be able to see the new "dd-wrt.com control panel".
13. Navigate to Wireless tab -> Basic Settings tab, and configure the wireless.  Save and apply the settings. Given a name to the wireless in "Wireless Network Name (SSID)".

14. Navigate to Wireless tab -> Wireless Security tab, and configure the wireless security. Use the following values for the settings
      a)  Security Mode : WPA2 Personal
      b)  WPA Algorithms : AES
      c)  Provide the shared key.
      d)  Save and apply the settings.

Reference

1. DD-WRT website
2. Upgrading WRT160N V3
3. Flashing with DD-WRT
4. Recovering from a Bad Flash
5. DD-WRT Forum