IT Technical Interview Questions
How would you analyze connection between a local host and a server?
A "TRACERT" command is used to accomplish this test. Trace Route can provide detailed path information taken through switches, servers, computers in reaching final destination.
Explain what Group Policy is.
A Group Policy is used to control user's desktops, computer configurations and permissions by creating a template for specific groups of members. This makes it easier to control and process large groups of users. For example; Tech Support may have different security permissions compared to regular computer users.
What is a Network Switch?
A Network Switch is used to create or control a network at physical layer in which multiple devices are connected and share data. This is accomplished by receiving, processing and forwarding of data in form of data packets.
What is PTR (Pointer Record)?
A PTR record resole an IP address to a full domain name. PTR records are used to check a server's association with the IP address from where the connection was initiated. PTR is often known as Reverse DNS because PTR associates and an IP with a domain name, opposite to DNS which points domains to IP addresses
What is a Subnet Mask?
A Subnet Mask holds the information about network and hosts addresses under a subnet. In order for TCP/IP protocol to figure out this information it looks at the 32bit subnet mask number. Typical example is 255.255.255.0
How does a VPN work?
A VPN builds a private network over a public network with extra encryption to connect users to the private network's resources. A VPN masks the original IP address, identity, and location of the originator of a web request
What is VPN?
A Virtual Private Network allows users to create a secure connection over public network such as internet. This is commonly used by mobile workers in order to access company's network from a remote location.
What is a domain?
A computer network that has user accounts, computer, printers and group policies. All the computers on the network are connected to the domain and it's centralized to each of those components.
What is a Cross Cable?
A cross table is used to connect two devices of the same type. It is usually used when we need to connect two devices in the absence of an intermediary device, such as a switch.
What is the difference between incremental backup and differential backup?
A differential backup only copies those files that were changed since the last full backup. For example, if I take a differential backup of my files today, the backup will copy everything that was changed since the last full backup. The full backup copies all data. An incremental backup copies everything that chnaged since the lst backup. The last backup does not necessarily have to be a full backup.
What is the difference between a forest and a domain?
A domain is a logic based group of computers, users and devices within Active Directory. A tree is a collection of domains; in case there are multiple trees formed a forest is created.
What is a Logical Drive?
A logical drive is virtual storage unit that exists on a physical hard drive but acts as an independent storage drive.
What is a Default Gateway?
A path for the computer to access other networks which you can have access by the ipconfig /all
What is the difference between serial and parallel ports?
A serial port transmits data one bit at a time in serial order, while a parallel port transmits 8 bits at a time.
What is Active Directory?
A service of Windows Server OS, Active Directory is used for user and computer authentication within a Domain. It can also enforce security policies with use of GPOs which can also be used to push software installs across domain.
How do you back up Active Directory?
Active Directory can be backed up by using NTBACKUP tool that comes with 2003 server. With 2008 server a command prompt is used to perform backup: type "wbadmin start systemstatebackup -backuptarget:e:" You can also perform a full server backup through Server Manager (OS 2012+).
What is Active Directory?
Active Directory is a service by MS that is used to manage, organize and run networks. Active Directory makes it easier for system administrators to find and use information related to all the users and objects in a network. An example would be using active directory to assign new policies to a specific group of users, restricting access to a printer for a specific user, or removing users from a network. Active Directory consists of different objects, like forests, domains, contacts, groups, sites, printers and subnets. It is a feature in Windows Server Operating System. Its used for host accounts, host name, and group policies. The user accounts are used to login to connect to this domain. The group policies are used to apply permission to the user or the domain.
A user is finding it difficult to configure a printer on their computer. How can you help them?
After making sure that the printer is powered on, and the computer is connected to the printer, I will open the "Add Printer" wizard in Windows and select the required printer from the list of available printers. I will use the "Add a Network, Wireless or Bluetooth" printer option if we are operating in a networked environment. I will also install and update printer drivers if necessary If the user's computer normally fails to detect their network printer, I will enable "Network Discovery" and "File and Printer Sharing" options in the Network and Sharing Center in Control Panel
A user is unable to log in their computer even when they are typing their password correctly. How can you solve this problem?
After making sure that the user is entering the right username and password, ill check the network cables and connectivity to ensure that the user is connected tot the network. I will also check whether the user is added in the domain. I can also use the "Manage User Account" option by signing in as an administrator to change the password of the problematic account and try signing in again. Running a system file check using the SFC command also helps in fixing this problem. Sometimes corrupt files hamper the sign-in process. Starting the computer in safe mode and trying to sing in with a local account, and doing a system restore or a complete reset of Windows can also help to solve this problem.
What is SSH and Port used?
Also known as Secure Shell; is used to establish a secure connection between devices which can be anything from computers to switches. For example; you can use SSH at a café and connect to any device anywhere; by establishing a configured Secure Shell tunnel between two devices. Thus, making the connection secure.
How many golf balls can you fit into a school bus?
Asses to think on your feet logically The volume of the golf balls The volume of the bus minus 20% of the seats
Tell me how future technology advances might impact your job?
Assessing your understanding of what is happening in your industry, it also assessing your reaction to it.
What is boot.ini and when do you use it?
Boot.ini is an initialization file usually found on older windows NT, XP, and 2000. This file contains boot options for computers with BIOS firmware. It is located in the root directory of the primary hard disk drive partition.
Which types of network cables are used in networking?
Cat-5 runs at 100Mb/s maximum, Cat-5e can run up to 1Gb/s, and Cat-6 can run up to 1OGb/s. Speeds are rated at 100 meters maximum distance.
You receive a trouble ticket that the monitor is not working. What is the first thing you should check?
Check the cables, make sure everything is plugged in and make sure the monitor is receiving power. If its still not working, then it mostly likely be the cable.
Explain Cookies
Cookies are small text files used to track a user's movement on a website. They are used to save the user's progress, remember their credentials, preferences and other data items. Cookies are stored on the user's computer.
What is DHCP?
DHCP stands for Dynamic Host Configuration Protocol. DHCP assigns unique IP addresses to hosts. We use DHCP to automate the process of IP address assignments, so that we have don't have to manually assign IP addresses to computers or devices in large networks.
What is DHCP?
DHCP stands for Dynamic Host Configuration Protocol. The main function of DHCP is to handle distribution of IP address on a network. Typically, IP address assigned by DHCP server are "Dynamic", meaning that they are leased and released dynamically (except static). To explain it further, if you connect a PC to a network it will get a leased IP address and if you disconnected or move the PC it will be assigned a new IP address.
How many queries does DNS perform and which ones?
DNS can perform two types of queries; Iterative and Recursive.
What is DNS and which port does it use?
DNS stands for Domain Name System and it's mostly used to interpret Domain names in to numeric IP address. For example; domain name CosmicNovo.com it's IP address is 130.211.160.109. DNS uses port 53 TCP or UDP.
You talked about DNS earlier in the interview. Can you explain what is DNS?
DNS translates domain names to IP addresses so that browsers can load internet and network resources for end users.
Active Directory database is located where?
Database is under the file name NTDS.DIT; and it is located in the %SystemRoot%\ntds folder of the server.
A user is unable to complete a training via ADLS (Videos will not load)
Driver problem Computer management Delete cookies and cache Web browser
What is the difference between FAT32 and NTFS?
FAT stands for file allocation table. It's relatively older file system that stores data in chunks of 32 bits. Its file size is extremely limited. NTFS stands for New Technology File System. It's a modern file system that supports large file sizes, recovery features, file permissions and hard links
What is FTP and Port used?
FTP is a File Transfer Protocol used to transfer large files between computers with built in ability to pause transfer of data. Ports used by FTP are 20 and 21.
What is a firewall?
Firewall is a filter between two or multiple computer sources; it blocks any incoming or outgoing traffic. Firewalls can be in software or hardware forms.
What is Reverse DNS Lookup and Forward DNS Lookup?
Forward DNS lookup converts domain names to IP addresses, while reverse DNS lookup converts IP addresses to domain names.
Do you know what Garbage Collection is?
Garbage Collection is a process designed to free space inside Active Directory. This is performed by default every 12 hours (defrag).
Can you explain the difference between HTTP and HTTPS?
HTTP stands for HyperText Transfer Protocol used by majority of websites as means of transmitting website data and it allows for use of hyperlinks. This Protocol mostly uses TCP port 80. HTTPS is a secure version of HTTP that allows for identity verification and low level encryption using TCP port 443.
How do you handle tight deadlines whilst working on technical-based projects?
I assess if there are any difficulties in accomplishing it and II would allocate additional time outside of normal working hours to get the project finished just in case we run into difficulties.
How do your technical knowledge up to date?
I like to keep up to date with technology, so I read material and follow a few online forums like BLANK and BLANK at least two times a week. This is great for emerging trends and it gives me an insight into what is happening now and what is likely to happen over the next few years in my sector. I also make sure I undertake some form of technical development online course via the website Udemy.com at lease once every quarter. For example, I recently completed an online SQL course to brush up my skills in this area and it only too me three days to complete. [Ask for script books] I take my professional development seriously and I will always make sure that is maintained moving forward.
How will you make sure that a system is not infected with a virus?
I will use a good anti-virus software to scan the computer for any viruses or malware. I will also look for signs of virus-related problems, including unexplained slow speed, endless pop-ups, spam, functioning of executable files, potientially unwanted programs, unfamiliar programs and unintended events.
What is IMAP?
IMAP is an email protocol. IMAP stands for Internet Message Access Protocol. It manages emails directly on the email server instead of downloading them on the end user device. All modern email clients and servers support IMAP.
What is an IP Address and how to find it?
IP address is a number assigned to your computer to identify its location on a network. Meaning that DHCP server will assign a number to each computer connected to a network as part of identification. You can find your IP address by using command prompt
Can you give an example of DNS issue.
If a host cannot be reached by it's name over the network but can be reached using an ip address indicates a problem with DNS.
What is a Lingering Object?
If an Object is deleted from Active Directory while Domain controller is offline it can create a lingering object. When object is deleted from Active Directory a Tomb Stone (which is temporary) is created which then has to be replicated by Domain Controller before it expires.
What is Safe Mode, how do you get to it, and what is it used for?
In order to reach Safe Mode, computer must be restarted and by pressing F8 key before the OS load you will arrive at the selection screen at which you will scroll up to select "Safe Mode". Safe Mode is used to troubleshoot driver issues, hardware issues and remove viruses or unwanted software. In Windows 10, the combination key is "Shift + Restart"
User is unable to open encrypted emails
Install 7zip to extract file Require to login to deencrypt then able to download the file
A user calls in and is unable to send/ receive emails.
Internet in the computer Account locked out Restart the computer The inbox is full Restart the outlook profile -> Test with the user -> apologize for doing things
What is ipconfig command used for?
Ipconfig command is used to determine TCP/lP settings, DHCP configuration, DNS, Default Gateway, and Subnet Mask. It can also be used to change Local DHCP settings; for example ipconfig /release and /renew.
What is DHCP (Dynamic Host Configuration Protocol)?
It is used to allocate IP addresses for every computer that is connected to the network
User is only able to access (.mil) sites. All other sites are providing an 'Access Denied' error
May require to install an certificate The website is fully blocked Network issue
Network Address Translation (NAT).
Most hosts on private networks are not configured with IP addresses that can communicate directly to the Internet. Instead, when clients on the local network connect via a router, the router converts the client's private IP address into a valid public address using Network Address Translation (NAT).
What is the job of network layer?
Network Layer deals with routing, switching and transmitting of data from one point to another, but this layer is also responsible for error handling and packet sequencing.
What is a PST file and why is it important?
PST stands for personal storage table. A pst table file is a file format built by Microsoft that is commonly used to store copies of emails, messages, calendar events, and other data items for applications like MS Outlook. The biggest advantage of a PST file is that it provides you with the portability to transfer your important outlook data from one computer to the next.
Describe a situation where you had an angry client or user
Patient and willing to listen no matter how angry they are Empathize with the client
What is a phishing attack?
Phishing is a type of cyberattack usually masquerading as web links, emails, and forums. When a user clicks on the malicious link, the attack initiates or the user is asked to enter sensitive information like cred card data, passwords, or social security numbers Example: a user recieves a link to sign up for a Bitcoin newsletter. When clicked, the link opens a registration form asking for the user's Gmail ID and password. The user enters the credentials, giving away their secret information to the hackers. As a result, the user's Gmal account is compromised.
How many streetlights are there in this country?
Population How many houses per streetlight How many people per house.
What is a proxy or proxy server?
Proxy deals with filtering network traffic in a sense of preventing access to certain websites and can even monitor user web activity. It can block certain website from being accessed but it can also act as a measure of hiding the true origin at point of access.
You receive a trouble ticket that states: My printer is not working properly; it prints out a weird pattern on the paper. Please assist.
Reinstall a proper printer driver in order to resolve this printing issue.
How does a router work?
Routers manage the flow of data to multiple connected network devices. If a packet has to go from Network A to Network D. The router connection the Network A devices will f irst identify the best possible path for the packet to get to Network D, or the closest network to the final destination. It does this by using a routing table to determine the best path based on the number of hops to the destination. In simple words, a router sends IP packets to other networks using the best possible path which identifie usng routing tables.
What is SCSI?
SCSI stands for Small Computer System Interface. It's a type of fast, parallel bus that is used to connect seeral devices within the computer, including hard disks, scanners, CD-ROM, and tape drivers.
What is VPN (Virtual Private Network)?
Secured to the businesses network
What is RAID?
Stands for Redundant Array of Independent Disks and is used to provide data redundancy (mirroring) across multiple hard disks. It can also be utilized to improve read/write performance across the server by using striping configuration. For example RAID 1; two or more disks with identical data stored (redundancy). RAID 0; two or more disks, data distributed evenly to improve performance (no redundancy).
Do you know what SYSVOL folder is?
System Volume folder is a directory that houses a copy of domain files found on a local hard drive within Domain Controller. This data is shared for purpose of replication across domain; for example user logon scripts and Windows Group Policy.
What is TCP/IP?
TCP is a Transmission Control Protocol that deals with establishing a connection between computers before any data is being sent; in other words it acts as the highway for data packets being sent back and forth used by various Protocols. For example; HTTP or FTP. TCP also controls and sorts out data packet receive order.
What is a ping command and its use?
Test the connection between two points in the network
What is an IP address and how do I find it?
The address is assigned to the computer on the network. In order to find the IP Address, through the command-line prompt, ipconfig /all
How you can you backup Outlook emails?
The best option is to use PST files to take Outlook backups We can use the export option in Outlook to get a PST file for Outlook data.
User is unable to log into a computer
The computer is not on The account is locked out The password is changed The computer fell off the domain
What is the loop-back IP address?
The loopback IP address is 127.0.0.1. As part of troubleshooting network connections issues; it is used to test Network lnterface Card for functionality. If you ping this IP address and it completes successfully it means your hardware is okay.
What is the maximum length of UTP cable allowed?
The maximum length of UTP is 90 to 100 meters for a single segment connection. If you have a switch or a repeater it can compensate for this limitation.
A user complains that their computer clock resets every time they restart their PC. How would you solve this problem?
The most common cause of this problem is a faulty CMOS battery which provides power to Complementary Metal Oxide Semiconductor (CMOS) chip. This chip stores key information like data and time. Replacing the CMOS battery solves this problem.
A user complains that their system is running very slow. How would you solve this problem?
The primary reason behind a slow computer is usually lack of sufficient memory. I will start by removing temporary files from the Windows folder. I will also, with the user's permission, delete any unused files and program that are taking up significant space on the hard disk. I will also run defragmentation tools to optimize space on the hard disk. If the user is facing slow performance while using the internet, I will delete cache from the browser. As a last resort, I'll explore the possibility of upgrading the hard disk to SSD, increasing RAM, or installing a more powerful processor.
What is the purpose of a logical drive?
The purpose of a logical drive is to optimize storage performance by making contiguous storage units, allow them to interact optimally without intervening with irrelevant or unrelated physical units. Logical drives add abstraction in storage, making it easier for the operating system to read from memory.
What are the layers of OSI model and how many?
There are 7 layers of OSI model: Physical Layer, Data Link, Network, Transport, Session, Presentation and Application.
You are asked by the company CEO to make sure that no employee in the company is able to open Facebook. How will you implement this policy?
There are several ways to do this, but the best one is to implement the restriction using the company's router. First, I will find out the IP address of the main router by using the IPconfig command. I will type the IP address in my browser to open the router's settings. I will then open the content filter section. I will add the facebook URL to the content filter option. This will block facebook for all users.
Which commands would you use in CMD to test network connectivity?
To test network connectivity ping, tracert or ipconfig commands can be used.
Can you explain what UDP is?
UDP stands for User Datagram Protocol. Unlike TCP, UDP is constantly broadcasting a connection signal which can allow for faster connection speeds-with TCP you have to wait for connection confirmation which takes time. UDP sends out data without consideration of what is receiving it; sort of like Radio signal.
VLAN
Virtual Local Area Network . The switches on an enterprise network can provide thousands of ports. it is inefficient to have that many connections to the same logical network. The ports are divided into groups using a feature of manages switches called VLAN. Each VLAN is associated with a different logical subnet address. Communications between different VLANS therefore have to go through a router. As well as improving performance, this is a security benefit too. traffic passing between VLANs can be easily filtered and monitored to ensure it meets security policies.
Do you know what Virtual Machine is?
Virtual Machine is an emulation version of Operating System. For example; you can have multiple copies of Windows running on a single computer.
How do you get the MAC address for a specific NIC?
We can also find it using ipconfig /all command.
What happens behind the scenes when you type "google.com" in the browser and hit enter?
When enter is pressed, the browser checks the cache of the browser, operating system, router, and ISP for the DNS record to find the corresponding IP address of www.google.com If the IP address of Google is not found in these caches, the ISP's DNS server will initiate a request to other DNS servers on the internet to find the IP address of google.com When my browser receives the appropriate IP address, it establishes a connection, usually a TCP connection. Once the connection is established, the data transfer process will start The browser will send a GET request asking for the google.com web page. The sever on the other end receives the request and the request handler (usually, a program written in common web languages like PHP, ASP, or RUBY) reads the request to identify what exactly is being requested and starts to assemble a response in the required format. The server response contains the require web page and other details like compression type. Cache format, cookie transformation, and more. The browser will render HTML and send more GET requests, if necessary, based on the HTML tags. Complete rendering will take place, which includes CSS, JavaScript files, images, and more. The google.com webpage will then appear on the browser.
What is Safe Mode, how do you get to it, and what is it used for?
While the computer is booting up, press and hold F8 and click on Safe Mode. Troubleshoot issues with hardware like hard drives. Safe Mode also allows to remove any viruses. Some files will be hidden unless I am login into Safe Mode.
What is Windows Domain?
Windows Domain provides access to user accounts, computers, printers and security features as part of database controlled by a domain controller.
Explain the role of Windows Server.
Windows OS Server acts as a centralized computer that provides specific functions and predetermined rules for computers, users and components connected to a network.
Can you tell me the difference between a workgroup and a domain?
With a Workgroup you have a collection of systems that are connected to the same network but have their own set of rules and permission set at local level. With a Domain you have a group of systems that are bound by the rules of a Domain Controller.
Ok. Can you tell me, in a bit more detail, how DHCP works?
Yes. A computer runs the DHCP client and sends a broadcast message requesting an IP address. The DHCP server sends an IP address to the computer. The computer accepts the IP address by sending a message back to the server. The server send an ACK message along with subnet masks, default gateway and other network details
Can you name different types of email servers and ports used?
You can have two types of email servers: Incoming Mail Server (POP3 port 110, IMAP 143, HTTP 80) Outgoing Mail Server (SMTP port 25)
What is a Default Gateway?
You can see what the Default Gateway is by performing an ipconfig /all command through CMD. Defualt Gateway serves as a path to reach other networks. For example, in order to reach the internet outside of your business or home; you need a gateway that will open the way for you. Default Gateway in a business environment is typically a proxy server.
What is the Blue Screen of Death (BSOD)?
You have the blue screen with a count down, which this indicates it is a software or hardware conflict or both. I would conduct a full diagnostic of the hardware and I would use the most up to date hardware. Clean the computer if necessary. The Blue Screen of Death is a critical error that occurs when the operating system cannot function, and it crashes. Mostly, BSoD problems are related to hardware, kernel, or drivers. Blue Screen of Death errors often show an error code or stop code which we can be used to find out the cause of the problem. To solve this problem, I will first restart the computer. If the computer restarts successfully, I will update all drivers. If the problem persists, I will disconnect all unnecessary hardware to rule out the external causes. I will also boot the computer in safe mode to see if the problem occurs in this basic state as well. Other fixes I can try include, checking the hard disk for bad sectors, system restore, installing updates if available, checking hard disk cables, and using the startup repair option from the boot menu.
Whats the difference between a router and a switch?
a router is responsible for moving data around a network of networks, known internet. While a switch forwards frames using hardware (MAC) addresses within a single network segment, a router forwards packets around an internetwork using logical network and hosts.
What are some commonly used LAN cables?
capacity Cat5- 100 mbps Cat5e-1Gbps Cat6-1/10Gbps Cat6a-10Gps
A Virtual Private Network (VPN)
connects the components and resources of two (private) networks over another (public) network. The Internet provides a cost effective way of connecting both users to networks and networks to networks. Rather than a user direct-dialing your server, which is private but expensive, the user connects to an ISP, which is cheap, but public.
Transmission Control Protocol
guarantees orderly transmission of packets at the transport layer. TCP can identify and recover from lost or out-of-order packets. This is used by most TCP/IP application protocols as failing to receive a packet or processing it incorrectly can cause serious data errors.
Internet Protocol
provides packet addressing and routing at the network layer. IP provides best effort delivery of an unreliable and connectionless nature. A packet might be lost, delivered out of sequence, duplicated, or delayed.
User Datagram Protocol
provides unreliable, non-guaranteed transfer of packets. UDP is an alternative way of implementing the transport layer to TCP. UDP is faster and comes with less of a transmission overhead because it does not need to send extra information to establish reliable connections. It is used in time- sensitive applications, such as speech or video, where a few missing or out-of-order packets can be tolerated. Rather than causing the application to crash, they would just manifest as a glitch in video or a squeak in audio.
Application Protocol
there are numerous protocols used for network configuration, management, and services. Application protocols use a TCP or UDP port to connect the client and server.
Access Point
works as a bridge, forwarding communications between the wireless stations and the wired network, referred to as a Distributed System. The access point will be joined to the network in much the same way as a host computer via a wall port and cabling to tan Ethernet switch.
