Update IP addresses at dynamic DNS services Using ddclient

ເດືອນກໍລະກົດ 22, 2008

If you are using zoneedit.com or dyndns.org for your DNS service so that you can access your server using a URL, then you might have to update your DNS record at the service periodically whenever the IP address of your computer changes.Now here is simple solution for this ddclient.

Update IP addresses at dynamic DNS services.A perl based client to update your dynamic IP address at DynDNS.com (or other dynamic DNS services such as Hammernode, Zoneedit or EasyDNS), thus allowing you and others to use a fixed hostname (myhost.dyndns.org) to access your machine. This client supports both the dynamic and (near) static services, MX setting, and alternative host. It caches the address, and only attempts the update if the address actually changes.

Install ddclient in ubuntu

sudo aptitude install ddclient

This will complete the installation

Configuring ddclient

If you want to reconfigure you seetings use the following command

dpkg-reconfigure ddclient

You want to make sure it runs as a service and monitors changes in ppp–something that the install wizard doesn’t cover.

Edit the configuration file /etc/ddclient.conf

sudo gedit /etc/ddclient.conf

# Configuration file for ddclient generated by debconf
# /etc/ddclient.conf

If you can’t find the public IP address, then you can have ddclient check your public IP address from the web by editing /etc/ddclient.conf and making it use the web by saying



use=web, web=checkip.dyndns.org/, web-skip=’IP Address’

Save and exit the file

Restart ddclient service using the following command

sudo /etc/init.d/ddclient restart

Ubuntu Networking Configuration Using Command Line

ເດືອນກໍລະກົດ 22, 2008

The basics for any network based on *nix hosts is the Transport Control Protocol/ Internet Protocol (TCP/IP) combination of three protocols. This combination consists of the Internet Protocol (IP),Transport Control Protocol (TCP), and Universal Datagram Protocol (UDP).

By Default most of the users configure their network card during the installation of Ubuntu. You can however, use the ifconfig command at the shell prompt or Ubuntu’s graphical network configuration tools, such as network-admin, to edit your system’s network device information or to add or remove network devices on your system

Configure Network Interface Using Command-Line

You can configure a network interface from the command line using the networking utilities. You configure your network client hosts with the command line by using commands to change your current settings or by editing a number of system files.

Configuring DHCP address for your network card

If you want to configure DHCP address you need to edit the /etc/network/interfaces and you need to enter the following lines replace eth0 with your network interface card

sudo vi /etc/network/interfaces

# The primary network interface – use DHCP to find our address
auto eth0
iface eth0 inet dhcp

Configuring Static IP address for your network card

If you want to configure Static IP address you need to edit the /etc/network/interfaces and you need to enter the following lines replace eth0 with your network interface card

sudo vi /etc/network/interfaces

# The primary network interface
auto eth0
iface eth0 inet static

After entering all the details you need to restart networking services using the following command

sudo /etc/init.d/networking restart

Setting up Second IP address or Virtual IP address in Ubuntu

If you are a server system administrator or normal user some time you need to assign a second ipaddress to your Ubuntu machine.For this you need to edit the /etc/network/interfaces file and you need to add the following syntax.Below one is the only example you need to chnage according to your ip address settings

sudo vi /etc/network/interfaces

auto eth0:1
iface eth0:1 inet static
network x.x.x.x
broadcast x.x.x.x
gateway x.x.x.x

You need to enter all the details like address,netmask,network,broadcast and gateways values after entering all the values save this file and you need to restart networking services in debian using the following command to take effect of our new ipaddress.

After entering all the details you need to restart networking services using the following command

sudo /etc/init.d/networking restart

Setting your ubuntu stytem hostname

Setting up your hostname upon a ubuntu installation is very straightforward. You can directly query, or set, the hostname with the hostname command.

As an user you can see your current hostname with

sudo /bin/hostname


To set the hostname directly you can become root and run

sudo /bin/hostname newname

When your system boots it will automatically read the hostname from the file /etc/hostname

If you want to know more about how to setup host name check here

Setting up DNS

When it comes to DNS setup Ubuntu doesn’t differ from other distributions. You can add hostname and IP addresses to the file /etc/hosts for static lookups.

To cause your machine to consult with a particular server for name lookups you simply add their addresses to /etc/resolv.conf.

For example a machine which should perform lookups from the DNS server at IP address would have a resolv.conf file looking like this

sudo vi /etc/resolv.conf

enter the following details

search test.com

XML Introduction

ເດືອນກໍລະກົດ 21, 2008

What is XML?

XML is a markup language for documents containing structured information.

Structured information contains both content (words, pictures, etc.) and some indication of what role that content plays (for example, content in a section heading has a different meaning from content in a footnote, which means something different than content in a figure caption or content in a database table, etc.). Almost all documents have some structure.

A markup language is a mechanism to identify structures in a document. The XML specification defines a standard way to add markup to documents.

What’s a Document?

The number of applications currently being developed that are based on, or make use of, XML documents is truly amazing (particularly when you consider that XML is not yet a year old)! For our purposes, the word “document” refers not only to traditional documents, like this one, but also to the myriad of other XML “data formats”. These include vector graphics, e-commerce transactions, mathematical equations, object meta-data, server APIs, and a thousand other kinds of structured information.

So XML is Just Like HTML?

No. In HTML, both the tag semantics and the tag set are fixed. An <h1> is always a first level heading and the tag <ati.product.code> is meaningless. The W3C, in conjunction with browser vendors and the WWW community, is constantly working to extend the definition of HTML to allow new tags to keep pace with changing technology and to bring variations in presentation (stylesheets) to the Web. However, these changes are always rigidly confined by what the browser vendors have implemented and by the fact that backward compatibility is paramount. And for people who want to disseminate information widely, features supported by only the latest releases of Netscape and Internet Explorer are not useful.

XML specifies neither semantics nor a tag set. In fact XML is really a meta-language for describing markup languages. In other words, XML provides a facility to define tags and the structural relationships between them. Since there’s no predefined tag set, there can’t be any preconceived semantics. All of the semantics of an XML document will either be defined by the applications that process them or by stylesheets.

So XML Is Just Like SGML?

No. Well, yes, sort of. XML is defined as an application profile of SGML. SGML is the Standard Generalized Markup Language defined by ISO 8879. SGML has been the standard, vendor-independent way to maintain repositories of structured documentation for more than a decade, but it is not well suited to serving documents over the web (for a number of technical reasons beyond the scope of this article). Defining XML as an application profile of SGML means that any fully conformant SGML system will be able to read XML documents. However, using and understanding XML documents does not require a system that is capable of understanding the full generality of SGML. XML is, roughly speaking, a restricted form of SGML.

For technical purists, it’s important to note that there may also be subtle differences between documents as understood by XML systems and those same documents as understood by SGML systems. In particular, treatment of white space immediately adjacent to tags may be different.

Why XML?

In order to appreciate XML, it is important to understand why it was created. XML was created so that richly structured documents could be used over the web. The only viable alternatives, HTML and SGML, are not practical for this purpose.

HTML, as we’ve already discussed, comes bound with a set of semantics and does not provide arbitrary structure.

SGML provides arbitrary structure, but is too difficult to implement just for a web browser. Full SGML systems solve large, complex problems that justify their expense. Viewing structured documents sent over the web rarely carries such justification.

This is not to say that XML can be expected to completely replace SGML. While XML is being designed to deliver structured content over the web, some of the very features it lacks to make this practical, make SGML a more satisfactory solution for the creation and long-time storage of complex documents. In many organizations, filtering SGML to XML will be the standard procedure for web delivery.

XML Development Goals

The XML specification sets out the following goals for XML: [Section 1.1] (In this article, citations of the form [Section 1.1], these are references to the W3C Recommendation Extensible Markup Language (XML) 1.0. If you are interested in more technical detail about a particular topic, please consult the specification)

  1. It shall be straightforward to use XML over the Internet. Users must be able to view XML documents as quickly and easily as HTML documents. In practice, this will only be possible when XML browsers are as robust and widely available as HTML browsers, but the principle remains.
  2. XML shall support a wide variety of applications. XML should be beneficial to a wide variety of diverse applications: authoring, browsing, content analysis, etc. Although the initial focus is on serving structured documents over the web, it is not meant to narrowly define XML.
  3. XML shall be compatible with SGML. Most of the people involved in the XML effort come from organizations that have a large, in some cases staggering, amount of material in SGML. XML was designed pragmatically, to be compatible with existing standards while solving the relatively new problem of sending richly structured documents over the web.
  4. It shall be easy to write programs that process XML documents. The colloquial way of expressing this goal while the spec was being developed was that it ought to take about two weeks for a competent computer science graduate student to build a program that can process XML documents.
  5. The number of optional features in XML is to be kept to an absolute minimum, ideally zero. Optional features inevitably raise compatibility problems when users want to share documents and sometimes lead to confusion and frustration.
  6. XML documents should be human-legible and reasonably clear. If you don’t have an XML browser and you’ve received a hunk of XML from somewhere, you ought to be able to look at it in your favorite text editor and actually figure out what the content means.
  7. The XML design should be prepared quickly. Standards efforts are notoriously slow. XML was needed immediately and was developed as quickly as possible.
  8. The design of XML shall be formal and concise. In many ways a corollary to rule 4, it essentially means that XML must be expressed in EBNF and must be amenable to modern compiler tools and techniques.
    There are a number of technical reasons why the SGML grammar cannot be expressed in EBNF. Writing a proper SGML parser requires handling a variety of rarely used and difficult to parse language features. XML does not.
  9. XML documents shall be easy to create. Although there will eventually be sophisticated editors to create and edit XML content, they won’t appear immediately. In the interim, it must be possible to create XML documents in other ways: directly in a text editor, with simple shell and Perl scripts, etc.
  10. Terseness in XML markup is of minimal importance. Several SGML language features were designed to minimize the amount of typing required to manually key in SGML documents. These features are not supported in XML. From an abstract point of view, these documents are indistinguishable from their more fully specified forms, but supporting these features adds a considerable burden to the SGML parser (or the person writing it, anyway). In addition, most modern editors offer better facilities to define shortcuts when entering text.

How Is XML Defined?

XML is defined by a number of related specifications:

Extensible Markup Language (XML) 1.0
Defines the syntax of XML. The XML specification is the primary focus of this article.
XML Pointer Language (XPointer) and XML Linking Language (XLink)
Defines a standard way to represent links between resources. In addition to simple links, like HTML’s <A> tag, XML has mechanisms for links between multiple resources and links between read-only resources. XPointer describes how to address a resource, XLink describes how to associate two or more resources.
Extensible Style Language (XSL)
Defines the standard stylesheet language for XML.

As time goes on, additional requirements will be addressed by other specifications. Currently (Sep, 1998), namespaces (dealing with tags from multiple tag sets), a query language (finding out what’s in a document or a collection of documents), and a schema language (describing the relationships between tags, DTDs in XML) are all being actively pursued.

Understanding the Specs

For the most part, reading and understanding the XML specifications does not require extensive knowledge of SGML or any of the related technologies.

One topic that may be new is the use of EBNF to describe the syntax of XML. Please consult the discussion of EBNF in the appendix of this article for a detailed description of how this grammar works.

VB6-Could not find acme setup

ເດືອນກໍລະກົດ 21, 2008


  1. Run> cmd
  2. at Setup folder RUN THIS COMMAND:

SETUP\ACMSETUP.EXE /T VS98Ent.STF /S E:/ \n “” /o “”

LDAP/PDC- Adding Windows and Linux user accounts in Zimbra Admin UI

ເດືອນມີນາ 25, 2008

Zimbra Open Source Linux and Mac Server

Zimbra Server is the core of Zimbra Collaboration Suite; it is designed with an extremely stable and modular architecture using proven open source technologies. Zimbra Server provides tremendous flexibility because it contains all of the components necessary to run your Linux or Mac based email and calendar messaging infrastructure out of the box; it also connects to just about every popular end-user client through the many standard protocols it supports.

Key benefits of the Zimbra Server:

  • Fast, easy install – all dependent components are packaged together in one simple installer
  • Proven open source – built with Linux, Apache Tomcat, Postfix, MySQL, OpenLDAP, Lucene
  • Uses industry standard open protocols – SMTP, LMTP, SOAP, XML, IMAP, POP, iCal, CalDAV
  • Efficiency and horizontal scalability – Zimbra server is 3-5x faster than comparable systems, plus each server has its own data store, message store, and set mailbox accounts. To scale simply add more servers.
  • Software as a Service (SaaS) ready – Multi-tenancy, delegated admin, runs on commodity hardware
  • Easy to administer and maintain – familiar open source components, robust migration tools, key feature advantages like real-time backup and restore; intuitive Ajax-based web Admin Console

Ref.: http://www.zimbra.com/products/zimbra_linux_mac_server.html

Sabaidee All

ເດືອນມີນາ 19, 2008

Welcome to my Blog !

My name is Kheuangkham Phothisan, my blog are going to provide information about technical works in many areas:-

  • System Design and Architecture
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  • and etc.

Hello world!

ເດືອນມີນາ 19, 2008

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