Top 15 Interview Questions with Answers for System Administrators
Q1: What is Active Directory?
Active Directory provides a centralized control for network administration and security. Server computers configured with Active Directory are known as domain controllers. Active Directory stores all information and settings for a deployment in a central database, and allows administrators to assign policies and deploy and update software.
Q2: What is NetBIOS protocol?
NetBIOS (Network Basic Input/Output System) Protocol allows applications on separate computers to communicate over a LAN. It runs over TCP/IP giving each computer in the network a NetBIOS name and IP address. E.g. It can be used for computers running Windows 2000 (or before) to join a computer network running Windows 2000 (or later).
Q3: What are FSMO Roles?
FSMO roles are server roles in a Forest
There are five types of FSMO roles
2-Domain naming master
Q4: What is LMHOSTS file?
It’s a file stored on a host machine that is used to resolve NetBIOS to specific IP addresses.
Q5: What is ARP?
ARP is used to resolve a known IP address to a MAC address. For a host to communicate with another host, it must know the MAC address of the destination host (if they are on the same network) or next-hop router. This is the reason for ARP.
Q6: What is APIPA?
(Automatic Private IP Addressing) The Windows function that provides DHCP auto configuration addressing. APIPA assigns a class B IP address from 169.254.0.0 to 169.254.255.255 to the client when a DHCP server is either permanently or temporarily unavailable. Designed for small non-routable networks, if a DHCP server becomes available later, the APIPA address is replaced with one from the DHCP server. For example, when a Windows Vista machine starts up, it waits only six seconds to find a DHCP server before assigning an IP from the APIPA range. It then continues to look for a DHCP server. Previous versions of Windows looked for a DHCP server for up to three minutes. See DHCP auto configuration addressing, DHCP and private IP address.
Q7: What ports are used by DHCP and the DHCP clients?
Requests are on UDP port 68, Server replies on UDP 67
Q8: DNS zones – describe the differences between the 4 types.
i)Forward Lookup Zones :-
This zone is responsible to resolve host name to ip.
ii)Reverse Lookup Zones :-
This zone is responsible to resolve ip to host name.
iii)Stub Zone :-
Stubzone is read only copy of primary zone.but it contains
only 3 records the SOA for the primary zone, NS record and a Host (A) record.
Q9: DNS record types – describe the most important ones.
Type of Record What it does
A (Host) Classic resource record. Maps hostname to IP(ipv4)
PTR Maps IP to hostname (Reverse of A (Host)
AAAA Maps hostname to ip (ipv6)
Cname Canonical name, in plain English an alias.such as
Web Server,FTP Server, Chat Server
NS Identifies DNS name servers. Important for forwarders
MX Mail servers, particularly for other domains.MX records
Q10: What is Domain Controller?
A domain controller (DC) or network domain controller is a Windows-based computer system that is used for storing user account data in a central database. It is the center point of the Windows Active Directory service that authenticates users, stores user account information and enforces security policy for a Windows domain.
A domain controller allows system administrators to grant or deny users access to system resources, such as printers, documents, folders, network locations, etc., via a single username and password.
Q11: What is Group Policy?
Group Policy allows you to implement specific configurations for users and computers. Group Policy settings are contained in Group Policy objects (GPOs), which are linked to the following Active Directory service containers: sites, domains, or organizational units (OUs).
Q12: What are GPOs (Group Policy Objects)?
A Group Policy Object (GPO) is a collection of settings that control the working environment of user accounts and computer accounts. GPOs define registry-based policies, security options, software installation and maintenance options, script options, and folder redirection options.
Q13: Where is the AD database stored?
The AD database is stored in C:WindowsNTDSNTDS.DIT.
Q14: What is the SYSVOL folder?
The SYSVOL folder stores the server copy of the domain’s public files that must be shared for common access and replication throughout a domain.
All AD databases are stored in a SYSVOL folder and it’s only created in an NTFS partition. The Active Directory Database is stored in the %SYSTEM ROOT%NDTS folder.
Q15: What do Forests, Trees, and Domains mean?
Forests, trees, and domains are the logical divisions in an Active Directory network.
A domain is defined as a logical group of network objects (computers, users, devices) that share the same active directory database.
A tree is a collection of one or more domains and domain trees in a contiguous namespace linked in a transitive trust hierarchy.
At the top of the structure is the forest. A forest is a collection of trees that share a common global catalog, directory schema, logical structure, and directory configuration. The forest represents the security boundary within which users, computers, groups, and other objects are accessible.
Source : Corvit Training