Thursday, March 31, 2011

Set up Virtual Mail Server using Postfix in Ubuntu Hardy

These are few things which need to be taken care of cautiously:
1. In postfix's main.cf file - ensure 'mydestinations' parameter is set to blank. Otherwise the domain folder and user mail dir will not be created in the server (although it shows in the mysql tables). The IMAP server testing in test_config page of Roundcube will show error message "no file/directory is found/created".
2. If Posfixadmin is intended to be installed as mail manager for setup virtual domain/user, let the postfixadmin do the table creation. The database and super user account can be created earlier.
3. Roundcube web mail; if the user needs to login to his/her account at the first time, make sure '$rcmail_config['auto_create_user'] value is set to 'true'. Other wise it keep displaying the login page.


Thursday, February 17, 2011

Gloomy Day!

What a pathetic! I am so bored with my current job. Gonna start thinking 'bout job hunting. Preferably in server or database administration. Doesn't matter if the pay was unattractive. But I need to buckle up my life! Despair...

Wednesday, February 16, 2011

Active Directory/Domain Controller Recovery Plan

Recently the domain controller (PDC) in my workplace which holds authentication,security,global policy,FSMO roles and operates as DNS server was inevitably crash down. Hence, no replication service on AD objects between PDC and another DC was implemented and set up. The reason we never set up this is because our network was small with less than 200 clients (terrible thinking, what a mistake).

  1. Modification on Default Global policy in order to stop W32.Conficker-A from spreading and threatens company's domain (as a matter of fact, I did this registry mess up to curb with the virus).Network services I.e RPC,Net Logon Workstation,Server had failed to start normally after server reboot.

  2. Constant threat by Virus/malware I.e Conficker on timely basis.

    Impact on Affected Area

    -File and printer sharing across the domain were blocked.

    -Users can't log on into the domain as normal.

    -Temporarily halted the database backup and report viewing thru BI tools (except for SQL database users setting).

Symptoms

  1. Receieved error message: Domain Controller for this domain could not be contacted.

  2. Run dcdiag.exe produced below error message:

Warning: DcGetDcName(TIME_SERVER) call failed, error 1355
A Time Server could not be located.
The server holding the PDC role is down.
Warning: DcGetDcName(GOOD_TIME_SERVER_PREFERRED) call failed, error 1355
A Good Time Server could not be located.
Warning: DcGetDcName(KDC_REQUIRED) call failed, error 1355
A KDC could not be located - All the KDCs are down.
......................... hospitalmetro.com failed test FsmoCheck

  1. Error message when opening GPO,ADSAS, ADUC snap-in where no domain controller was found in the list.

  2. Network services e.g Net Logon,RPC,Workstation,Server etc could not be started.

  3. The NetLogon and SYSVOL share were missing (not shared).

  4. Clients could not use file and printing sharing services across domain.

    Applying Recovery Plan Solution

    Several methods have been identified to curb with Failed Domain Controller. These selected methods significantly relevant to particular symptoms only and do not suitable fo every recovery actions.

    Method 1

    1. Run dcdiag.exe /s:locahost.

    2. Received error message as above.

    3. Try restore the Group Policy Object using dcgpofix.exe /target:[both|domain|dc]

    4. Failed. Result produced error message “dcgpofix could not open AD object LDAP://rootDSE

    5. The cause of the error was caused by the network servcies I.e Net Logon, RPC etc could not being started using Services.msc snap-in or via command prompt.

    Method 2

    1. Restore AD objects using Non-Authoritative or Normal Restore method

    2. This method reinstates AD data to the state before the backup for single domain controller.

    3. Reboot the DC and press F8 to enter into Safe Mode environment.

    4. On the Boot Menu section, select Directory Services Restore Mode

    5. Open NTBackup.exe and perform restore to Original Location.

    6. Restart the server to the Normal Mode.

    7. The NTBackup utility will restore the System State data back to previous setting prior to server crash.

    8. To produce the System State backup, use NTBackup.exe utility and select System State checkbox as what to backup.

    Conclusion

    1. Schedule backup on DC's System State on timely fashion.

    2. Best practice stipulates that the Default Domain and Default DC Group Policy Object should not be modified. Instead, create new GPOs and link them to relevant containers I.e Computers,Users,DC,OU, MSH etc.

    3. Compulsory to have another DC (BDC) (replication services) or create another standby DC with DNS service.

Sunday, February 13, 2011

MYKAD .Net Software Development SDK Package

~ Unlimited used of Dynamic Link Library (DLL) file with source codes.
~Developed guna vb .net 2005 express edition (free download)
~Compiled using .Net Framework 2.0 atau ke atas.
~Sample program with source code juga diberi.
~ Tested on standard USB mykad reader.
~ Sesuai utk student dan novice coders understand COM/DLL development.

Aku bagi sekali dengan utiliti e.g package installer,Smartcard tools etc. Smaple code ni boleh retrieve basic info and photo dari mykad. Berminat? Aku jual dgn harga RM50. delivery akan dibuat guna Email. Sebarang pertanyaan, boleh komen di bawah. TQ

Thursday, February 10, 2011

Setting Mail Server in Ubuntu Server 8.04 using Postfix

~For three days, I have been doing in-depth testing on Ubuntu 8.04's Linux Server to deploy a Mail Server runs on Postfix as SMTP agent, integrates with Courier to provide POP3 and IMAP services, where these services are equipped with authentication packages. This mail service runs on MySQL backend with virtual domain and virtual users creation.
~ To conclude, I managed to deploy it for the client access using web-based email i.e Roundcube.
~ Initially, I have installed LAMP,Bind9 for DNS setup and phpMyAdmin.
~ Finally I managed to send email using Outlook Express which carried more than 20MB in size to other users. (This will also be explained in my next blog later).
~I will explain the installation later on my next writing. See ya!