Domain,Tree,Forest & Domain Controller

Domain: Domain is a logical grouping present in the network, in which one or more systems can access one or more shared resources and there is a centralized database.
              All the systems are depend upon the Server carrying the Database.
              Once we created Domain, it logically creates Domain,Tree and Forest 
Tree: Tree is a set of one or more Domains with contiguous names or Collection of multiple Domains.
Root Domain: The first Domain created is the "Root Domain" of the first tree.The first domain that you create in your Active Directoryforest is automatically designated as the forest root domain     
Child Domain: Other Domains in the same domain tree is called Child Domain.
Parent Domain: A Domain immediately above another domain in the same domain tree is it Parent Domain 

Forest: Forest is a collection of multiple Trees.

Domain Controller: The system which maintain Active Directory Service(ADS) is called Domain
Controller.
ADDS: In Windows Server 2008 the Active Directory Service(ADS) is called Active Directory Domain
Service(ADDS).                                

smtp mail test in windows with Telnet

Testing with Telnet: Sent a mail using command line
You can also use TELNET to test your SMTP service. SMTP uses port number 25,so in order to use telnet to open an SMTP session with the command
telnet abc.test.com  25 or telnet 192.168.10.17  (EX:IP of smtp server space and port number)
If the connection is successful, we should see a banner and a command line interface.We then need to follow RFC 821 for the accepted SMTP commands, which are quite simple(as the name says...)
220 abc.test.com Microsoft ESMTP MAIL Service, Version: 5.0.2195.5329 ready at Mon,25
Nov 2002 02:51:06 +0200
helo abc.test.com or helo 192.168.10.17 (EX:ip address of smpt or name)
250 abc.test.com Hello [192.168.0.100]
mail from:admin@gmail.com or mail form zyz (Ex:can specify mail id or name)
250 2.1.0 admin@gmail.com....Sender OK
rcpt to:testmailid@gmail.com  (mail id to whom you want to send)
250 2.1.5 testmailid@gmail.com
data
354 Start mail input; end with .(Means once you done with matter then press enter and .(dot) to finish)
subject: this is a test
Hi John
I'm trying to test this connection from Telnet.
Let me know if you get this message.
. (this dot will end of your mail matter)

=========================
options to send mail
=========================
telnet [-a][-e escape char][-f log file][-l user][-t term][host [port]]
 -a      Attempt automatic logon. Same as -l option except uses
         the currently logged on user's name.
 -e      Escape character to enter telnet client prompt.
 -f      File name for client side logging
 -l      Specifies the user name to log in with on the remote system.
         Requires that the remote system support the TELNET ENVIRON option.
 -t      Specifies terminal type.
         Supported term types are vt100, vt52, ansi and vtnt only.
 host    Specifies the hostname or IP address of the remote computer
         to connect to.
 port    Specifies a port number or service name.

Virtualization

Virtualization:Industry moving from concept of buying to leasing
    Software as a Service  ( SaaS)
    Platform as a Service  (PaaS)
    Hardware as a Service  ( HaaS)

Virtualization is the creation of a virtual (rather than actual) version of something, such as an operating system,  a server, a storage device or network resources.
Allows to create multiple virtual machines on a single physical server
Allows to run multiple operating System environment in a single Physical server.
Better utilization of Hardware resources  -  CPU, Memory
Reduces the need for huge no of  Physical servers

There are several different forms of virtualization that need to be understood as a basis for making the right technology choice.
 * Network virtualization is a method of combining the available resources in a network by splitting up the available bandwidth into channels, each of which is independent from the others, and each of which can be assigned (or reassigned) to a particular server or device in real time. The idea is that virtualization disguises the true complexity of the network by separating it into manageable parts, much like your partitioned hard drive makes it easier to manage your files.
    * Storage virtualization is the pooling of physical storage from multiple network storage devices into what appears to be a single storage device that is managed from a central console. Storage virtualization is commonly used in storage area networks (SANs).
    * Server virtualization is the masking of server resources (including the number and identity of individual physical servers, processors, and operating systems) from server users. The intention is to spare the user from having to understand and manage complicated details of server resources while increasing resource sharing and utilization and maintaining the capacity to expand later.
    * Server Hardware Virtualization. Also known as a hypervisor, Server Hardware Virtualization runs a very lightweight core operating system. The hypervisor can host independent virtual machines (VMs). This form of virtualization requires hardware that has embedded virtualization awareness capabilities. Since the hypervisor is very lightweight, there is little overhead in the system, which allows for more scalability in the virtual machines.
    * Server Software Virtualization: An operating system, such as Windows Server® 2003 or Windows Server 2008, runs an application that is able to host virtual machines. Each virtual machine runs a completely separate operating system and application set.
    * Presentation Virtualization: Centralized systems host multiple user sessions, and all processing is done on those host systems. The user sessions are isolated from each other. Only the presentation information, such as keyboard and mouse inputs, and video updates are sent between the client and the host system. The client can be a full Windows-based workstation or a Windows-based terminal device.
    * Application Virtualization: An application is isolated from the underlying operating system by means of wrapper software that encapsulates it. This allows multiple applications that may have conflicting dynamic link libraries (DLLs) or other incompatibilities to run on the same machine without affecting each other.
    * Desktop Virtualization: This is similar to Server Software Virtualization, but it runs on client systems such as Windows Vista®. The client operating system runs a virtualization application that hosts virtual machines. This is often used when a specific person needs to run one or a limited number of legacy applications on a legacy operating system.
Virtualization products
Linux
Linux virtualization users have two free, open source hypervisors to choose from: Xen and KVM.
VMware
VMware workstation
VMware Fusion ( MAC os)
VMware server  ( GSX Server)
VMware ESX Server 4.0/4.0i & Vsphere
Microsoft
Microsoft Virtual PC
Microsoft Virtual Server
Hyper-V  (This feature available only on Microsoft Windows Server 2008 )
Citrix
XEN Server
Virtualization environment
Host Machine -  Physical server/Machine where Virtualization software deployed
Virtualization software  :  Software that allows to create, manage virtual machines & Virtual environment
Guest operating system :  Operating system installed into virtual machine 
Virtual Machine or VM :A machine is made up of Software files, provides Virtual hardware created by Virtualization software.A Virtual Machine will have Virtual Devices like Processor, Disk, Ethernet, Motherboard, VGA, etc..

properties of user in linux

To check the user properties grep for a user name. 
root# grep user-name | /etc/passwd
user-name:x:500:500: :/home/user-name:/bin/bash # this line contains 7 information of a user.

{user-name}:{x}:{500}:{500}:{ }:{/home/user-name}:{/bin/bash} # I have divided each part with a bracket.

1.{user-name}                    = User name 
2.{x}                                   =Encrypted password
3.{500}                               =UID
4.{500}                               =GID
5.{ }                                    =Comment
6.{/home/user-name}         =User's default or home directory
7.{/bin/bash}                      =Default Shell of Linux

Users in Linux

In Linux platform their are 2 types of user such as System User and Normal User
System User : The user which are created default by Operating System are called system users.The function of this user to access or manange system services which cannot be utilized by normal user. The system services are Ex:shutdown,restart and application service like mail services and apache services etc..
The system users can also be recognized with the help of an UID(Unique Identifier) which starts from 0(zero) and  reserved up-to 499 by default.

Normal User: The user which are created manually by an administrator or by a system user to access system objects and resources are called normal users. Normal user can be recognized with the help of an UID(Unique Identifier) which starts from 500 and reserved up-to 60,000 by default.

Authentication Protocol in Windows

NTLM(New Technology Lan Manager)
It is used authenticating user credentials in a work-group model.In a work-group model SAM(Security Account Manager) database used to store and retrieve user credentials.

Kerberos
It is used to authenticating user credentials in a Domain environment. In a Domain environment NTDS.DIT database is used to store and retrieve user credentials.

Configure Static IP for OpenSolaris

Configure Static IP for OpenSolaris
Follow step below:
   1. svcadm disable network/physical:nwam (Execute in terminal)
   2. svcadm enable network/physical:default (Execute in terminal)
   3. cp /etc/nsswitch.dns /etc/nsswitch.conf
   4. Put DNS in /etc/resolv.conf ( eg: nameserver 172.16.17.x, this should be your dns server ip)
   5. Put the default router(gateway) ip into /etc/defaultrouter (eg:172.16.17.11)
   6. #dladm show-phys or ifconfig -a (Check the Enternet Interface of your system.
   7. If your Ethernet interface name is e1000g0, create /etc/hostname.e1000g0, and add below two lines as
       eg: line 1: 172.16.17.x (the static IP you wuold like to assign)
            line 2: netmask 255.255.255.0 broadcast + up
   8. Restart Machine (Some time reoot is not required, for confirmation reboot and check if you are getting
    static ip)

Outher OpenSolaris commands
cat /etc/nwam/llp ( to check the ip )
#svcadm restart network/physical:nwam (Restart nwam:)
Add your new IP and hostname into /etc/hosts following the same format as already exists
#svcadm enable network/physical:default
#svcadm restart network/routing-setup (To add just the ip address of your default router to /etc/defaultrouter)
#dladm show-phys or ifconfig -a (Check the Enternet Interface of your system.
LINK         MEDIA               STATE      SPEED  DUPLEX    DEVICE
yge0            Ethernet               unknown    0           unknown      yge0
e1000g0      Ethernet               up              1000      full              e1000g0
e1000g1      Ethernet               unknown    0            half             e1000g1
ath0             Wifi                     up              1000      full              ath0