Wednesday, October 19, 2011

Common Windows System / Network Administrator Questions With Answers


What is DHCP’s purpose?
DHCP’s purpose is to enable individual computers on an IP network to extract their configurations from a server (the ‘DHCP server’) or servers, in particular, servers that have no exact information about the individual computers until they request the information. The overall purpose of this is to reduce the work necessary to administer a large IP network. The most significant piece of information distributed in this manner is the IP address.
What protocol and port does DHCP use?
DHCP, like BOOTP runs over UDP, utilizing ports 67 and 68.
What is Global Catalog? The Global Catalog authenticates network user logons and fields inquiries about objects across a forest or tree. Every domain has at least one GC that is hosted on a domain controller. In Windows 2000, there was typically one GC on every site in order to prevent user logon failures across the network.
What is Stub Zone in DNS Server?
A stub zone is a copy of a zone that contains only those resource records necessary to identify the authoritative Domain Name System (DNS) servers for that zone. A stub zone is used to resolve names between separate DNS namespaces. This type of resolution may be necessary when a corporate merger requires that the DNS servers for two separate DNS namespaces resolve names for clients in both namespaces.
A stub zone consists of:
  • The start of authority (SOA) resource record, name server (NS) resource records, and the glue A resource records for the delegated zone.
  • The IP address of one or more master servers that can be used to update the stub zone.
The master servers for a stub zone are one or more DNS servers authoritative for the child zone, usually the DNS server hosting the primary zone for the delegated domain name.
Where is the file of Active Directory data file stored?
Active Directory data store in %SystemRoot%\ntds\NTDS.DIT. The ntds.dit file is the heart of Active Directory including user accounts
What are the types of records in DNS?
To see the records of DNS Server checks this path - DNS Records
What is DHCP and at which port DHCP work?
Dynamic Host Configuration Protocol (DHCP) is a network protocol that enables a server to automatically assign an IP address to a computer from a defined range of numbers (i.e., a scope) configured for a given network. DHCP assigns an IP address when a system is started
DHCP client uses port 67 and the DHCP server uses port 68.
What is DORA process in DHCP and How it works?
DHCP (D)iscover
DHCP (O)ffer
DHCP (R)equest
DHCP (A)cknowledge
1) Client makes a UDP Broadcast to the server about the DHCP discovery.
2) DHCP offers to the client.
3) In response to the offer Client requests the server.
4) Server responds all the Ip Add/mask/gty/dns/wins info along with the acknowledgement packet.
What is Super Scope in DHCP?
A superscope allows a DHCP server to provide leases from more than one scope to clients on a single physical network. Before you can create a superscope, you must use DHCP Manager to define all scopes to be included in the superscope. Scopes added to a superscope are called member scopes. Superscopes can resolve DHCP service issues in several different ways; these issues include situations in which:
  • Support is needed for DHCP clients on a single physical network segment—such as a single Ethernet LAN segment—where multiple logical IP networks are used. When more than one logical IP network is used on a physical network, these configurations are also known as multinets.
  • The available address pool for a currently active scope is nearly depleted and more computers need to be added to the physical network segment.
  • Clients need to be migrated to a new scope.
  • Support is needed for DHCP clients on the other side of BOOTP relay agents, where the network on the other side of the relay agent has multiple logical subnets on one physical network. For more information, see “Supporting BOOTP Clients” later in this chapter.
  • A standard network with one DHCP server on a single physical subnet is limited to leasing addresses to clients on the physical subnet.
What is Stub zone DNS?
A stub zone is a copy of a zone that contains only those resource records necessary to identify the authoritative Domain Name System (DNS) servers for that zone. A stub zone is used to resolve names between separate DNS namespaces. This type of resolution may be necessary when a corporate merger requires that the DNS servers for two separate DNS namespaces resolve names for clients in both namespaces.
A stub zone consists of:
  • The start of authority (SOA) resource record, name server (NS) resource records, and the glue A resource records for the delegated zone.
  • The IP address of one or more master servers that can be used to update the stub zone.
The master servers for a stub zone are one or more DNS servers authoritative for the child zone, usually the DNS server hosting the primary zone for the delegated domain name
What is Active Directory? Active Directory is a network-based object store and service that locates and manages resources, and makes these resources available to authorized users and groups. An underlying principle of the Active Directory is that everything is considered an object—people, servers, workstations, printers, documents, and devices. Each object has certain attributes and its own security access control list (ACL).
What’s the difference between forward lookup zone and reverse lookup zone in DNS?
Forward lookup is name-to-IP address; the reverse lookup is IP address-to-name.
How to transfer roles in Active Directory?
Using Ntdsutil.exe we can transfer roles in Active Directory. To know more regarding role transfer click this link.
How to backup Active Directory and which main file you take in backing of Active Directory?
We can take backup with Ntbackup utility.
Active Directory is backed up as part of system state, a collection of system components that depend on each other. You must backup and restore system state components together.
Components that comprise the system state on a domain controller include:
  • System Start-up Files (boot files). These are the files required for Windows 2000 Server to start.
  • System registry.
  • Class registration database of Component Services. The Component Object Model (COM) is a binary standard for writing component software in a distributed systems environment.
  • SYSVOL. The system volume provides a default Active Directory location for files that must be shared for common access throughout a domain. The SYSVOL folder on a domain controller contains:
    • NETLOGON shared folders. These usually host user logon scripts and Group Policy objects (GPOs) for non-Windows 2000based network clients.
    • User logon scripts for Windows 2000 Professionalbased clients and clients that are running Windows 95, Windows 98, or Windows NT 4.0.
    • Windows 2000 GPOs.
    • File system junctions.
    • File Replication service (FRS) staging directories and files that are required to be available and synchronized between domain controllers.
  • Active Directory. Active Directory includes:
    • Ntds.dit: The Active Directory database.
    • Edb.chk: The checkpoint file.
    • Edb*.log: The transaction logs, each 10 megabytes (MB) in size.
    • Res1.log and Res2.log: Reserved transaction logs.

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