Top Google Network Engineer Interview Questions

. How do TFTP and FTP application layer protocols differ?

A local host can download files from a distant host using the trivial file transfer protocol (TFTP), but it lacks security and reliability. It uses UDP's basic packet delivery functions. The usual method offered by TCP/IP for copying a file from one host to another is the File Transfer Protocol (FTP). It is dependable and secure because it uses TCP's services. It creates two links (virtual circuits) between the hosts, one for informational control and the other for data transport.

What are the functions of a network administrator?

A network administrator has many responsibilities that can be summarized into 3 key functions: installation of a network, a configuration of network settings, and maintenance/troubleshooting of networks.

What do you mean by a network?

A network can be considered as a set of devices of systems that are connected. They can communicate and share information. Devices such as computers, laptops, servers, and printers can be connected through networks like LAN (Local Area Network) and WAN (Wide Area Network).

What do you mean by a node?

A node is a point where two or more devices connect within a network. A node is where data is received, stored, sent and created within the network. Nodes can be an endpoint for transmitting data or a redistribution point. Any device connected to another device inside a network is a node itself. Common examples of nodes are switches, routers, bridges, and servers, which may be connected or other devices through the internet.

What is a node?

A node refers to a point or joint where a connection takes place. It can be a computer or device that is part of a network. Two or more nodes are needed to form a network connection.

What do you mean by a point to point link?

A point to point link is a connection between two dedicated networking devices. The complete bandwidth of the link is utilized for the transmission of data between two devices. There may be multiple connections between devices. Using a PPP link, two different networks can be connected, where one network will work as the endpoint for another. These days PPP links are created using modems and PSTN (Public Switched Telephone Networks). An example of a PPP link is a telephone call between two people.

What is a proxy server?

A proxy server conducts the heavy lifting of accessing and retrieving for users similar to how a DNS server caches the addresses of accessed websites. Additionally, proxy servers maintain a list of websites, whether they are whitelisted or banned, to protect consumers from easily avoidable viruses. These days, most big enterprises and institutions use proxies to enhance network performance.

What is a router?

A router is a physical device that is used for receiving, storing, analyzing and forwarding data packets to other nodes inside or outside the network. Routers can connect to devices such as a modem, optic fiber and a cable to connect and share information between devices. Routers contain firmware and software. Firewalls are installed in routers for securing the network. Moreover, routers use forwarding tables and headers for determining the best path for transferring the data packets.

What is the difference between a straight-through and crossover cable?

A straight-through cable is used to connect computers to a switch, hub, or router. A crossover cable is used to connect two similar devices, such as a PC to PC or Hub, to the Hub.

Which LAN cable types are commonly used? What is a cross cable?

"Cat 5" and "Cat 6" are the LAN cable types most often used. The speed limits for "Cat 5" and "Cat 6" are 100 Mbps and 1 Gbps, respectively. A cross table connects same-type devices for interaction without needing a switch or hub.

Define subnet mask

A subnet mask is a number that specifies the range of IP addresses that are available in a network. A subnet mask puts a limit on the number of valid IP addresses. This is the 32-bit number that is used for masking the IP address. Subnet mask divides the IP address into a host address and network address. Two or more systems within the same subnet can communicate with each other. If a system is connected to a network, its subnet mask can be determined by accessing the Network Control Panel.

Give some examples of private network addresses.

10.0.0.0 with a subnet mask of 255.0.0.0172.16.0.0 with subnet mask of 255.240.0.0192.168.0.0 with subnet mask of 255.255.0.0

What are Ethernet LANs 10base2, 10base5, and 10baset?

10Base2: A contiguous cable segment length of 100 meters and a maximum of 2 segments are required for 10Base2: An Ethernet term that refers to a maximum transmission rate of 10 Megabits per second using baseband signaling. 10Base5: 10Base5 is an Ethernet phrase that refers to 5 continuous segments with a maximum distance of 100 meters between them and a maximum transfer rate of 10 Megabits per second using baseband signaling. 10BaseT: An acronym for Ethernet that refers to twisted-pair wiring and a top transfer rate of 10 Megabits per second.

What is a subnet mask?

A subnet mask is combined with an IP address to identify two parts: the extended network address and the host address. Like an IP address, a subnet mask is made up of 32 bits.

What is a firewall?

A firewall is a network security device that supervises traffic entering and leaving a network. Its primary purpose is to create a barrier between the internal network and external sources to avoid malicious traffic, like viruses or malware.

What sets apart Arp from Rarp?

A host or router can utilize the address resolution protocol (ARP), which determines the physical address of another host on its network by sending an ARP query packet with the recipient's IP address. When a host just knows its physical address, the reverse address resolution protocol (RARP) enables it to find its Internet address.

Can you state the differences between a switch, router, and a hub?

A switch is used for forwarding the data packets in a network. It facilitates error checking for the data packets and send error-free packets to the destined ports properly. A router is a networking device that transfers data packets after analyzing their contents. The correct destination, correctness and IP address of the data packets are checked by the router. They make use of a routing table for finding out the best path for transmission. A hub is a connection point for networking devices. Different segments of a LAN are connected using a LAN. It also has several ports for communication. If a packet arrives at a hub port, it is copied to the other ports so that it is visible to the other segments of the LAN. But as they are unable to filter data, it sends the data packets to all the connected devices.

What are the differences between a switch and a hub?

A hub and a switch are both networking devices that help you connect to various devices. The hub is the layer 1 device, i.e., it works at the physical layer and sends the signal to the port. Meanwhile, the switch is a layer 2 device that routes and transmits information over a network. The following table highlights the key differences between a hub and a switch:

What is a Hybrid Network?

A hybrid network is a network setup that makes use of both client-server and peer-to-peer architecture.

What is a hybrid routing protocol?

A hybrid, or both the Distance Vector and Link State Routing protocol methods, offer these benefits: Traditional Distance Vector updates are sent. Routing tables between neighbors are synchronized upon startup and deliver particular updates in response to changes in the network topology.

When troubleshooting computer network problems, what common hardware-related problems can occur?

A large percentage of a network is made up of hardware. Problems in these areas can range from malfunctioning hard drives, broken NICs, and even hardware startups. Incorrect hardware configuration is also one of those culprits to look into.

What is a layer?

A layer divides the PDU (protocol data unit) process entirely logically. They specify the method by which data is sent through a network from one machine to another.

What are the different technologies involved in establishing WAN links?

Analog connections - using conventional telephone lines Digital connections - using digital-grade telephone lines Switched connections - using multiple sets of links between the sender and receiver to move data.

What is anonymous FTP?

Anonymous FTP is a way of granting user access to files in public servers. Users that are allowed access to data in these servers do not need to identify themselves, but instead, log in as an anonymous guest.

. What Is BSOD? How can you fix your computer if it has a blue screen?

BSOD stands for "Blue Screen of Death." A blue screen with a code appears when a hardware or OS issue prevents the Windows operating system from functioning. The best solution is to boot from the "Last Known Good Configuration" on the PC. Boot the machine in safe mode. And if that doesn't work, it could signify issues with the devices or driver.

What is the advantage of address sharing?

By using address translation instead of routing, address sharing provides an inherent security benefit. That's because host PCs on the Internet can only see the public IP address of the external interface on the computer. Instead, it provides address translation and not the private IP addresses on the internal network.

What is routing?

Routing chooses the traffic path across multiple networks, between two networks or within a network. Different types of networks, such as computer networks and circuit-switching networks, support routing. Routing entails making decisions to direct data packets from the source to the destination.

What is SLIP?

SLIP, or Serial Line Interface Protocol, is an old protocol developed during the early UNIX days. This is one of the protocols that are used for remote access.

What is SMTP?

SMTP is short for Simple Mail Transfer Protocol. This protocol deals with all internal mail and provides the necessary mail delivery services on the TCP/IP protocol stack.

What is SMTP?

SMTP stands for Simple Mail Transfer Protocol. This protocol is used for delivering emails over a network from one system to another. It is a part of the TCP/IP application layer protocol that uses a method called "store and forward". This is used for sending emails across the networks with the help of a Mail Transfer Agent. SMPTP can send messages to one or more clients within or outside the network. These messages can include text, voice, images or graphics.

What is SSH?

SSH, or Secure Shell, is most popular among Linux users but has a wide range of applications. Systems, switches, thermostats, or toasters, may all be connected securely over a tunnel, thanks to SSH. SSH also offers the unique ability to act as a tunnel for other programs, which is conceptually comparable to a VPN. If configured properly, even insecure programs or programs operating via insecure connections can be used in a secure state.

Mention the different types of LAN cables used in networking. What do you mean by a cross cable?

Some of the common types of LAN cables that are used in networking are CAT 5 and CAT 6. CAT 5 provides 100 Mbps of speed and CAT 6 offers 1 Gbps of speed. However, the three major types of network cables are coaxial, fiber optic and twisted pair. A cross cable is also called a crossover cable that is used for connecting two similar devices for communication without the help of a hub or a switch.

What is the job of the Network Layer under the OSI reference model?

The Network layer is responsible for data routing, packet switching, and control of network congestion. Routers operate under this layer.

Can you define the OSI model?

The OSI (Open System Interconnection) is a reference model that has the necessary protocols and standards for communicating over a network. The model was made by the International Organization for Standardization (ISO) in 1984. It consists of seven layers, where each layer has a different function. These layers are Physical Layer, Data Link Layer, Network Layer, Transport Layer, Session Layer, Presentation Layer, and Application Layer.

What is the TCP IP model in networking?

The TCP IP (Transmission Control Protocol and Internet Protocol) model is a more precise representation of the OSI model. The current architecture of the internet is based on the TCP IP model. It was developed by the Department of Defence's Project Research Agency as a part of their project for communication within systems and remote machines. It has 4 layers that have protocols required for communication between devices of a network. They are as follows: Application Layer (Process layer) Transport Layer (Host-to-Host layer) Internet Layer Link Layer (Network Access)

What is the equivalent layer or layers of the TCP/IP Application layer in terms of the OSI reference model?

The TCP/IP Application layer has three counterparts on the OSI model: 1) Session Layer, 2) Presentation Layer, and 3) Application Layer.

What Is the IP address for APIPA? When the DHCP server is unavailable, what IP address is sent to the computer?

The Windows client machine automatically assigns itself an IP address known as an APIPA when a DHCP server is unavailable, to communicate with other network computers.

What is HTTPS, and what port does it use?

The big brother of HTTP, HTTPS stands for Secure HTTP (not to be confused with HTTPS, a separate protocol). HTTPS, which was created for identity verification, uses SSL certificates to confirm the server you are connected to is authentic. Although HTTPS has certain encryption capabilities, they are typically judged insufficient, and additional encryption methods are preferred whenever practical. TCP port 443 is used for HTTPS transmission.

What is a Decoder?

The decoder is a type of circuit that converts the encoded data to its original format. It also converts the digital signal into an analog signal.

What protocols fall under the Application layer of the TCP/IP stack?

The following are the protocols under the TCP/IP Application layer: FTP, TFTP, Telnet, and SMTP.

Can you differentiate between the internet, intranet, and extranet?

The internet is a global network that connects thousands of computers. Information can be accessed and shared from any location that has access to the internet. An intranet is a network that is unique to a firm where data is accessed and shared among the computers within that network only. An extranet is a network where only specific members are allowed access. These may include vendors, customers, suppliers, and other officials who are associated with a company. The extranet handles the secure part of the website that is accessed through IDs and passwords.

How would you define CSMA/ CD?

CSMA/ CD stands for Carrier-sense multiple access Collision Detection. This protocol defines the way two devices interact when a data collision occurs. The protocol has rules of how long the devices in a network must wait when a collision happens. It analyses if the communication channel is busy or not, and controls the transmission accordingly. If it detects a collision, the transmission of the station is stopped. It then sends a jam signal and waits for some time before transmitting again.

What is the difference between CSMA/CD and CSMA/CA?

CSMA/CD, or Collision Detect, retransmits data frames whenever a collision occurred. CSMA/CA, or Collision Avoidance, will first broadcast intent to send prior to data transmission.

What happens when you use cables longer than the prescribed length?

Cables that are too long would result in signal loss. It means that data transmission and reception would be affected because the signal degrades over length.

What is ICMP?

ICMP is an Internet Control Message Protocol. It provides messaging and communication for protocols within the TCP/IP stack. This is also the protocol that manages error messages that are used by network tools such as PING.

What is ICMP?

ICMP stands for Internet Control Message Protocol. Its main function is to inform systems when they attempt a remote connection whether the other end is accessible.

What is the role of the IEEE in computer networking?

IEEE, or the Institute of Electrical and Electronics Engineers, is an organization composed of engineers that issues and manages standards for electrical and electronic devices. This includes networking devices, network interfaces, cablings, and connectors.

How are IP addresses arranged and displayed?

IP addresses are displayed as a series of four decimal numbers that are separated by period or dots. Another term for this arrangement is the dotted-decimal format. An example is 192.168.101.2

What is IPX?

IPX, or Internetwork Packet Exchange, was a fairly lightweight protocol, which was advantageous given the limitations of computers at the time. It is a TCP/IP rival that performs admirably in small networks, has little to no configuration, and does not require components like DHCP. However, it does not scale effectively for applications like the Internet. As a result, it was abandoned and is no longer a necessary protocol for the majority of pieces.

What is IPv6?

IPv6, or Internet Protocol version 6, was developed to replace IPv4. At present, IPv4 is being used to control internet traffic but is expected to get saturated in the near future. IPv6 was designed to overcome this limitation.

What are some drawbacks of implementing a ring topology?

In case one workstation on the network suffers a malfunction, it can bring down the entire network. Another drawback is that when there are adjustments and reconfigurations needed to be performed on a particular network, the entire network must be temporarily brought down.

How does dynamic host configuration protocol aid in network administration?

Instead of having to visit each client computer to configure a static IP address, the network administrator can apply dynamic host configuration protocol to create a pool of IP addresses known as scopes that can be dynamically assigned to clients.

How do you define a Mac address?

It is the LAN card's 48-bit hardware address. The network adapter card typically keeps the MAC address in ROM, and it is distinct.

What is a point to point link?

It refers to a direct connection between two computers on a network. A point to point connection does not need any other network devices other than connecting a cable to the NIC cards of both computers.

What is a LAN?

LAN stands for Local Area Network. It refers to the connection between computers and other network devices that are located within a small physical location.

What are MAC addresses?

MAC, or Media Access Control, uniquely identifies a device on the network. It is also known as a physical address or an Ethernet address. A MAC address is made up of 6-byte parts.

What is the standard color sequence of a straight-through cable?

Orange/white, orange, green/white, blue, blue/white, green, brown/white, brown.

What is peer to peer?

Peer to peer (P2P) are networks that do not rely on a server. All PCs on this network act as individual workstations.

Explain profile in terms of networking concepts

Profiles are the configuration settings made for each user. A profile may be created that puts a user in a group, for example.

You need to connect two computers for file sharing. Is it possible to do this without using a hub or a router?

Yes, you can connect two computers, using only one cable. A crossover type cable can be used in this scenario. In this setup, the data transmit pin of one cable is connected to the data receive pin of the other cable, and vice versa.

. How can you recover data if a virus infects your system?

You can set up a different system and install the most recent versions of the OS and antivirus software. Then, connect the infected HDD to the system as a secondary disc. After that, wipe and scan the backup HDD. Now, you can transfer the files to the new system.

How can you make a machine become a router?

Your device will be configured as a router if it has at least two additional interfaces in addition to lo0, or if it has at least one point-to-point interface. Solaris 2.x: When the computer has two or more interfaces, the IP layer typically behaves as a router (forwarding datagrams that are not addressed to it, among other things). By setting the /dev/ip variable ip forwarding with ndd(1M), you can override this behavior. 0 indicates do not proceed, and the number 1 indicates proceed.

How do domains work?

When we install Active Directory, a domain is formed. It's a security barrier that controls computers inside of it. Using a domain, you can centrally manage computers and control them with group policies.

What is the importance of implementing a Fault Tolerance System?

A fault tolerance system ensures continuous data availability. This is done by eliminating a single point of failure.

What is a MAC address?

A MAC (Media Access Control) address is used for uniquely identifying a device on a network. Also called the physical address or ethernet address, MAC addresses are 48-bit numbers that are present in the NIC of the devices. This is an address given by the manufacturer of the device. The MAC sub-layer of the data link layer makes use of the MAC addresses. They are 12-digit hexadecimal numbers, where the first 6 digits identify the manufacturer.

What is one basic requirement for establishing VLANs?

A VLAN is required because at the switch level. There is only one broadcast domain. It means whenever a new user is connected to switch. This information is spread throughout the network. VLAN on switch helps to create a separate broadcast domain at the switch level. It is used for security purposes.

What is a backbone network?

A backbone network is a centralized infrastructure created to provide several networks with varied routes and data. It also manages channel and bandwidth control.

What is the backbone network?

A backbone network is a centralized infrastructure that is designed to distribute different routes and data to various networks. It also handles the management of bandwidth and multiple channels.

What do you mean by a backbone network?

A backbone network is a network that has the connectivity infrastructure that is the main link for the various parts of a network. It has the capability of supporting networks spread over vast geographical areas. It can connect different networks within the same area or building, or different buildings within an area. Typically, a backbone network comprises routers, bridges, gateways, and switches.

How can you fix signal attenuation problems?

A common way of dealing with such a problem is to use repeaters and hubs because it will help regenerate the signal and therefore prevent signal loss. Checking if cables are properly terminated is also a must.

What is a link?

A connection between two or more devices is called a link. A link defines different protocols that help a device to connect with another device within a network.

What safeguards do you put in a network design to limit data loss?

A: Data loss can cause systems to stop and productivity to grind to a halt. This risk is a common one that the network engineer should be prepared for. Look for an answer that goes into detail on the type of safeguards they use and why they have selected them.What to look for: Selection process Understanding of data loss risk Experience with this situation Example: "I build disaster recovery resources into the network plan and focus on high availability. Company data is safeguarded in several ways, such as regularly scheduled backups and distributed network storage locations."

Q: Can you draw a network topography you worked on before and explain the design to me?

A: One of the primary duties of a network engineer is creating the network blueprints for your organization. The applicant should be able to quickly sketch out a diagram and explain their decision-making process behind that topography.What to look for: Well-illustrated design Easy to understand explanation Solid network design Example: "This network topography is what I implemented at a mid-size financial organization. I needed to keep security and availability at the forefront of the design, which is why I used this particular configuration to serve their needs."

What is the importance of APIPA in networking?

APIPA stands for Automatic Private IP Addressing. This is an important feature of Windows systems that allow the device to assign an IP address to itself when there is no DHCP. This IP address has a range of 169.254.0.1 through 169.254.255.254. Any client system can use this APIPA address until the DHCP server is available. This facility is commonly used for small organizations having about 25 clients.

What is the main disadvantage of a peer to peer network?

Accessing the resources that are shared by one of the workstations on the network takes a performance hit.

What is active directory?

An active directory provides ways to handle the relationships and identities within a network. It allows the network administrator to manage domains, objects, and users in a network. The admin can create a user group and assign special access privileges to them for accessing specific directories on the server. The 3 main components of the active directory structure are Domain Trees Forests

Where is the best place to install an Anti-virus program?

An anti-virus program must be installed on all servers and workstations to ensure protection. That's because individual users can access any workstation and introduce a computer virus. You can plug in their removable hard drives or flash drives.

Describe networking.

Networking refers to the interconnection between computers and peripherals for data communication. Networking can be done using wired cabling or through a wireless link.

Explain the importance of authentication.

Authentication is the process of verifying a user's credentials before he can log into the network. It is normally performed using a username and password. This provides a secure means of limiting access from unwanted intruders on the network.

What is a client/server?

Clients and servers collaborate as different logical entities to complete a network task.

Explain clustering support

Clustering support refers to the ability of a network operating system to connect multiple servers in a fault-tolerant group. The main purpose of this is the if one server fails, all processing will continue with the next server in the cluster.

. How do cross cables differ from regular LAN cables? What is the LAN cable's maximum possible length?

Cross cable and standard LAN cables differ in the manner that the paired wires are joined to the connector (RJ45). The theoretical length is 100 meters, however, after you pass 80 meters, the signal loss may cause your speed to decline.

Have you coordinated with development teams and other stakeholders while deploying network resources?

Cross-collaboration between teams and departments is a common trend in the business world. The available network resources can significantly impact an organization's software development and other projects. The applicant should provide an answer that makes you feel confident in their ability to communicate and work with multiple people. What to look for: Strong communication skills Ability to coordinate Experience working with other teams

What is DHCP?

DHCP is short for Dynamic Host Configuration Protocol. Its main task is to assign an IP address to devices across the network automatically. It first checks for the next available address not yet taken by any device, then assigns this to a network device.

What do you understand by DHCP?

DHCP stands for Dynamic Host Configuration Protocol. This protocol assigns IP addresses and network configuration parameters to devices within a network. It helps the devices to communicate with each other and reduces the problems caused due to the allocation of IP addresses manually. DHCP allocates addresses from its pool of IP addresses to network devices. The protocol initially checks whether the next available address is assigned to a device. If not, it allocates a device to this IP address.

What is a DNS?

DNS stands for domain name system. Websites are accessed by their domain names such as google.com and yahoo.com. But these names are not understood by the computer. The DNS translates these names into IP addresses so that the browsers can load them for the users. DNS converts the hostname of the website into an IP address that is readable by the computer. The converting of hostnames into IP addresses is called forward lookup. Converting or resolving IP addresses into hostnames is called backward lookup.

What is data encapsulation?

Data encapsulation is the process of breaking down information into smaller, manageable chunks before it is transmitted across the network. In this process that the source and destination addresses are attached to the headers, along with parity checks.

What is the use of a default gateway?

Default gateways provide means for the local networks to connect to the external network. The default gateway for connecting to the external network is usually the address of the external router port.

What is DoS?

DoS, or Denial-of-Service attack, is an attempt to prevent users from being able to access the Internet or any other network services. Such attacks may come in different forms and are done by a group of perpetrators. One common method of doing this is to overload the system server so it cannot anymore process legitimate traffic and will be forced to reset.

What is DNS, and why is it employed? What do A and MX records mean?

Domain Naming Service, or DNS, is used to translate between names and IP addresses. While we can easily recall names, the computer can only understand numbers. Therefore, we give computers and websites names. When we use these names (such as yahoo.com), the computer converts the request to an IP address (a number) via DNS. "A" record: This is a host record and maps a name to an IP address. It uses the DNS record of the Domain Name System (DNS) to obtain a name's IP address. "MX" Record: MX, or mail exchanger records are required to identify the network's mail servers.

What do understand by domain and workgroup?

Domain is a group of computers in a network, which are connected. The members of a domain consist of users, workstations and database servers. Devices within the same domain are administered using the same protocols and rules. When an active directory is installed, a domain is created. Domains can be used for administering computers centrally, which is not possible in a workgroup. A workgroup is a set of connected computers that share resources. Here, all the computers are peers and they do not have control over one another. All peers must be on the same LAN and subnet.

. What is DHCP, and why is it employed? What are superscopes and scopes?

Dynamic Host Configuration Protocol (DHCP): In a network setting, DHCP distributes IP addresses to many PCs, simplifying IP address management. Scope: A scope is a collection of IP addresses a client can use to communicate with other network PCs. Gateway IP, Subnet masks, DNS server IP, and exclusion range are included in IP addresses.

What is IP?

Each device (such as a computer or printer) in a computer network that uses Internet Protocol (IP) is assigned a numerical label known as an Internet Protocol address (IP address). The IP of your system or device uniquely identifies it from a large network of computers.

What is the importance of Encryption on a network?

Encryption is the process of translating information into a code that is unreadable by the user. It is then translated back or decrypted back to its normal readable format using a secret key or password. Encryption ensures that information that is intercepted halfway would remain unreadable because the user must have the correct password or key for it.

Describe Ethernet

Ethernet is one of the popular networking technologies used these days. It was developed during the early 1970s and is based on specifications, as stated in the IEEE. Ethernet is used in local area networks.

What is the distinction between an "extended" and "standard" ACI (Access Control List)?

Extended ACLs are source- and destination-based. Standard ACLs are source-based.

Define anonymous FTP.

FTP stands for File Transfer Protocol, which is a communication protocol for exchanging files between computer systems over a network. A user can access files on public servers using anonymous FTP.

What is FTP and anonymous FTP?

FTP stands for file transfer protocol. This is used by the TCP/IP model for transferring files from a host system to another host system. It is used for downloading files from the server to a computer and transferring web pages very efficiently. Anonymous FTP is a method of providing access to certain public servers. Users who have been granted access to these servers do not need identification, instead, they can just log in as guests.

What are firewalls?

Firewalls serve to protect an internal network from external attacks. These external threats can be hackers who want to steal data or computer viruses that can wipe out data in an instant. It also prevents other users from external networks from gaining access to the private network.

What are the maximum networks and hosts in class A, B, and C network?

For Class A, there are 126 possible networks and 16,777,214 hosts. For Class B, there are 16,384 possible networks and 65,534 hosts. For Class C, there are 2,097,152 possible networks and 254 hosts

What is the number of network IDs in a Class C network?

For a Class C network, the number of usable Network ID bits is 21. The number of possible network IDs is 2 raised to 21 or 2,097,152. The number of host IDs per network ID is 2 raised to 8 minus 2, or 254.

Differentiate between "forward lookup" and "reverse lookup" in DNS.

Forward lookup converts names to IP addresses, while reverse lookup translates IP addresses to names.

What do fully qualified and partially qualified domain names mean?

Fully Qualified Domain Name A fully qualified domain name (FQDN) ends with a null or empty string (FQDN). Partially Qualified Domain Name A partially qualified domain name does not end with a null string (PQDN). A PQDN does not finish at the root; rather, it begins at a node.

What are gateways?

Gateways provide connectivity between two or more network segments. It is usually a computer that runs the gateway software and provides translation services. This translation is key in allowing different systems to communicate on the network.

What are manageable and unmanageable switches?

Manageable switches are customizable, configurable, and controllable. Unmanageable switches don't have any customizable or configurable settings.

What is mesh topology?

Mesh topology is a setup wherein each device is connected directly to every other device on the network. Consequently, it requires that each device has at least two network connections.

What is multicast routing?

Multicast routing is a targeted form of broadcasting that sends a message to a selected group of the user instead of sending it to all users on a subnet.

How does a network topology affect your decision to set a network?

Network topology dictates what media you must use to interconnect devices. It also serves as a basis on what materials, connectors, and terminations that is applicable for the setup.

Briefly describe NAT

NAT is Network Address Translation. This is a protocol that provides a way for multiple computers on a common network to share a single connection to the Internet.

Can you define NAT?

NAT stands for Network Address Translation. This is for IP networks that are using unregistered IP addresses. NAT enables them to connect to the internet. In this process, a public address is assigned to a system within a private network. NAT operates using a router and converts the private addresses into legal addresses. It is also used for securing networks by limiting the number of IP addresses a company can use within a network.

What do you mean by NIC?

NIC stands for Network Interface Card, also called an Ethernet card or a network adapter. This is a hardware component that is essential for connecting the computer to a network. NIC is a card that is installed in a system for connecting to the internet. This is important for wireless, wired and LAN communication. It has a unique MAC address that will help in identifying the computer within a network.

What is NIC?

NIC stands for network interface controller — a piece of computer hardware also known as a network card or network adapter. An NIC enables computer communication over a computer network.

What is NOS?

NOS, or Network Operating System, is specialized software. The main task of this software is to provide network connectivity to a computer in order to communicate with other computers and connected devices.

What is netstat?

Netstat is a command-line utility program. It provides useful information about the current TCP/IP settings of a connection.

What is Netstat?

Netstat stands for network statistics. It is a network utility of the command line. This command is used for displaying information about the TCP/IP settings, incoming and outgoing connections, network protocol statistics and routing tables. The command is used on Windows and Unix operating systems. Netstat is useful for determining the network traffic and problems in the network. On a Windows system, the command netstat can be entered in the command line. You will see a list of all active network connections.

Describe Network Topology

Network Topology refers to the layout of a computer network. It shows how devices and cables are physically laid out, as well as how they connect.

You'll likely need to explain complex technical ideas to coworkers and clients without the same level of technical knowledge as you. How will you ensure they understand what you're saying?

Network engineers must perform technical work and effectively communicate with internal and external stakeholders. The network engineer you hire should be able to handle technical tasks and clearly explain what's happening while doing so. Your candidate's answer should be easy to understand and provide concrete strategies for communication. Look for these qualities in your candidate's answer: Uses layman's terms Provides communication strategies Understands the importance of communication in the role A quality candidate answer might reflect this example: Example: "Whenever I'm tasked with explaining a technical concept to a coworker or client, I do my best to ensure they understand. I do this by avoiding technical jargon whenever possible and using layman's terms to explain the devices and processes. I also try to use analogies or metaphors to explain what's going on inside the devices. If possible, I draw diagrams of the devices themselves so the person can better visualize how the system works. I think it's important to empower people with knowledge, so they take more ownership in their network system."

What is OSI, and what role does it play in computer networks?

OSI (Open Systems Interconnect) serves as a reference model for data communication. It is made up of 7 layers, with each layer defining a particular aspect of how network devices connect and communicate with one another. One layer may deal with the physical media used, while another layer dictates how data is transmitted across the network.

Can you define OSPF?

OSPF stands for Open Shortest Path First. This is a link-state routing protocol that is used for identifying the best path for transferring data packets. This protocol is useful as it makes use of the network bandwidth efficiently.

What is the main purpose of OSPF?

OSPF, or Open Shortest Path First, is a link-state routing protocol that uses routing tables to determine the best possible path for data exchange.

What advantages does fiber optics have over other media?

One major advantage of fiber optics is that it is less susceptible to electrical interference. It also supports higher bandwidth, meaning more data can be transmitted and received. Signal degrading is also very minimal over long distances.

What is the disadvantage of a star topology?

One major disadvantage of star topology is that once the central Hub or switch gets damaged, the entire network becomes unusable.

What does FTP mean?

One of the big legacy protocols that ought to be phased out is FTP or File Transfer Protocol. FTP may resume downloads if they are paused and are primarily intended for massive file transfers. There are two methods for gaining access to an FTP server: Anonymous access and Standard Login. The main difference between the two is that while a Standard Login requires an active user login, Anonymous access does not. The user's credentials are delivered in cleartext using FTP, which makes it exceedingly easy for anyone listening on the wire to sniff the credentials. This is where the main issue with FTP resides.

What is Ping?

Ping is a utility program that allows you to check connectivity between network devices on the network. You can ping a device by using its IP address or device name, such as a computer name.

What is a private IP address?

Private IP addresses are assigned for use on intranets. These addresses are used for internal networks and are not routable on external public networks. These ensure that no conflicts are present among internal networks. At the same time, the same range of private IP addresses is reusable for multiple intranets since they do not "see" each other.

What is the use of a proxy server?

Proxy servers are used for securing a network from external users who might want to intrude into the network. It makes a computer system virtually invisible to others. A proxy server has a list of harmful websites so that the main network is protected. When it receives a request, it collects the data from the target web server and processes it. The response is then forwarded to the user.

What are proxy servers, and how do they protect computer networks?

Proxy servers primarily prevent external users who are identifying the IP addresses of an internal network. Without knowledge of the correct IP address, even the physical location of the network cannot be identified. Proxy servers can make a network virtually invisible to external users.

What is RAS?

RAS, or remote access services, connects remote access to resources that might normally reside on a network of IT devices.

What is RIP?

RIP, short for Routing Information Protocol is used by routers to send data from one network to another. It efficiently manages routing data by broadcasting its routing table to all other routers within the network. It determines the network distance in units of hops.

10. What Is RIS? What is imaging/ghosting?

RIS stands for Remote Installation Services. Once the installed image has been saved to a Windows server, RIS can set up the new hardware. It can be used to deploy server and client operating systems. Ghosting, also known as imaging, accomplishes the same task by capturing an installed image and later installing it on new hardware. Because installing an OS from a CD every time might be time-consuming, we choose either RISE or imaging/ghosting.

What is the RSA algorithm?

RSA is short for the Rivest-Shamir-Adleman algorithm. It is the most commonly used public-key encryption algorithm in use today.

When it comes to networking, what are rights?

Rights refer to the authorized permission to perform specific actions on the network. Each user on the network can be assigned individual rights, depending on what must be allowed for that user.

What are routers?

Routers can connect two or more network segments. These are intelligent network devices that store information in its routing tables, such as paths, hops, and bottlenecks. With this info, they can determine the best path for data transfer. Routers operate at the OSI Network Layer.

How can you manage a network using a router?

Routers have a built-in console that lets you configure different settings, like security and data logging. You can assign restrictions to computers, such as what resources it is allowed access or what particular time of the day, they can browse the Internet. You can even put restrictions on what websites are not viewable across the entire network.

What common software problems can lead to network defects?

Software related problems can be any or a combination of the following: Client-server problems Application conflicts Error in configuration Protocol mismatch Security issues User policy and rights issues

Describe star topology

Star topology consists of a central hub that connects to nodes. This is one of the easiest to set up and maintain. Advantages: Here are pros/benefits of start topology: Easy to troubleshoot, set up, and modify. Only those nodes are affected, that has failed. Other nodes still work. Fast performance with few nodes and very low network traffic. In Star topology, addition, deletion, and moving of the devices are easy. Disadvantages: Here are cons/drawbacks of using Star: If the Hub or concentrator fails, attached nodes are disabled. The cost of installation of star topology is costly. Heavy network traffic can sometimes slow the bus considerably. Performance depends on the Hub's capacity A damaged cable or lack of proper termination may bring the network down.

What is TCP/IP?

TCP is the Transmission Control Protocol and IP is the Internet Protocol.

What does 10Base-T mean?

The 10 refers to the data transfer rate. In this case, it is 10Mbps. The word Base refers to baseband, as opposed to broadband.

What is the active directory?

The Active Directory is a directory service that manages network environments' identities and connections. It is a collection of processes and services that help users leverage network resources to accomplish their tasks.

What is 127.0.0.1?

The IP address 127.0.0.1 is a reserved address that is used for localhost connections. It is a special IPv4 address that is also called a loopback address. It is not a real IP address but all systems have this address which means "this computer". During any connection issues, the server is pinged to check whether it is responding with the help of this address. The address is only used by the computer you are currently working on.

6. What Is the command Ipconfig and why is it employed?

The IPCONFIG command displays IP information assigned to a computer. We can determine the computer's assigned IP address, DNS IP address, and gateway IP address from the output.

What is the difference between ipconfig and ifconfig commands?

The ipconfig command stands for Internet protocol configuration that is used for configuring networking devices on Windows machines. All the TCP/IP network summary data can be displayed through this command using the command line. It is also used for refreshing the settings of Dynamic Host Configuration Protocol (DHCP) and Domain Name System (DNS). The ifconfig stands for interface configuration. The command is used for configuring and managing the network interface parameters on the TCP/IP network. The network interface IP addresses can be viewed with the help of this command. The command is used on MAC, LINUX and Unix operating systems.

What is the main job of the ARP?

The main task of the ARP or Address Resolution Protocol is to map a known IP address to a MAC layer address.

what is the maximum segment length of a 100Base-FX network?

The maximum allowable length for a network segment using 100Base-FX is 412 meters. The maximum length for the entire network is 5 kilometers.

Explain Mesh Topology

The mesh topology has a unique network design in which each computer on the network connects to every other. It is developing a P2P (point-to-point) connection between all the devices of the network. It offers a high level of redundancy, so even if one network cable fails, data still has an alternative path to reach its destination.

What is the importance of the OSI Physical Layer?

The physical layer does the conversion from data bits to the electrical signal, and vice versa. This is where network devices and cable types are considered and setup.

What is the purpose of cables being shielded and having twisted pairs?

The primary purpose of this is to prevent crosstalk. Crosstalk's are electromagnetic interferences or noise that can affect data being transmitted across cables.

What is the proper termination rate for UTP cables?

The proper termination for unshielded twisted pair network cable is 100 ohms.

What resources do you use to stay on top of innovations in the industry?

The technology industry is fast-paced, and new network solutions could significantly improve your infrastructure. The network engineer should have the initiative to continually learn about the latest and greatest technology. You're not looking for any particular resource in the applicant's answer, simply that they do stay on top of things. What to look for: Dedication to learning Reasons for choosing the resources Ability to stay on top of trends

What are the three different types of routing tables?

The three types of routing tables are fixed, dynamic, and fixed central. A fixed table must be manually updated for every change. A dynamic table updates data in response to network activity, minimizing the need for manual maintenance. A fixed central table lessens the need to update the tables on each system. Dynamic tables typically present network administrators with the fewest issues, despite the fact that the table's contents may change without the administrator being aware of the change.

What is a tracert command?

The tracert command is used for displaying information about the path taken by a data packet to reach the destination network from the router. The total number of hops taken by the packet during the transmission is also displayed.

What protocols fall under the TCP/IP Internet Layer?

There are 4 protocols that are being managed by this layer. These are ICMP, IGMP, IP, and ARP.

What are the layers of the OSI reference model?

There are 7 OSI layers: 1) Physical Layer, 2) Data Link Layer, 3) Network Layer, 4) Transport Layer, 5) Session Layer, 6) Presentation Layer, and 7) Application Layer.

How many layers are there under TCP/IP?

There are four layers: 1) The Network Layer, 2) Internet Layer, 3) Transport Layer, and 4) Application Layer.

What are the different ways of securing a computer network?

There are several ways to do this. Install a reliable and updated anti-virus program on all computers. Make sure firewalls are setup and configured correctly. User authentication will also help a lot. All these combined would make a highly secured network.

44. What are the important topologies for networks?

There are three important topologies for networks: BUS topology: Each computer in a BUS architecture connects to a single line of principal network cables. It's affordable and simple to set up, comprehend, and extend. STAR topology: A single hub connects every system, making it easy to troubleshoot and reinstall. RING topology: A single computer connects to two other computers from the rear and front ends. When all computers connect, they form a ring-like structure. This ensures equal access to network resources for all computers and less signal degradation compared to other topologies.

What is meaning by tunnel mode?

This is a mode of data exchange wherein two communicating computers do not use IPsec themselves. Instead, the gateway that is connecting their LANs to the transit network creates a virtual tunnel. So, it uses the IPsec protocol to secure all communication that passes through it.

What is the function of the OSI Session Layer?

This layer provides the protocols and means for two devices on the network to communicate with each other by holding a session. This includes setting up the session, managing information exchange during the session, and tear-down process upon termination of the session.

Can you walk me through your troubleshooting process when you aren't getting the expected performance out of your network configuration?

This question gives you a first-hand look at the way the applicant approaches a complex problem. There are countless ways to approach this issue, and it's valuable to see how the applicant goes about it.What to look for: Analytical thinking Solid process Willingness to ask for help Example: "The first thing I do is eliminate any low-hanging fruit. I'll check for network outages, hardware failures, high network activity and other common causes of poor performance. Once I've ruled those out, I'll use network monitoring and analytics tools to get more information about the cause of the problem. I'll also reach out to network administrators and technicians to speed up the process if I run into problems."

What kinds of transmission media are available?

Two transmission media are available: guided and unguided. Guided Media, such as twisted-pair, coaxial cable, and fiber-optic cable, act as a conduit from one device to another. Any of these media's physical boundaries direct and confine a signal as it travels along them. Metallic materials that accept and transport signals in the form of electrical current are used in twisted-pair and coaxial cables. A glass or plastic cable called an optical fiber accepts and transmits signals in the form of light. Unguided Media is wireless media that transmits electromagnetic waves without a physical conductor. Signals can be sent through the air. Radio communication, satellite communication, and mobile telephony are used for this.

What is UDP?

UDP stands for User Datagram Protocol. It is a communication protocol for computer applications to transmit messages, here known as datagrams, to other hosts on a network that follows the Internet Protocol (IP). It is a connectionless communication protocol.

What is a USB?

USB stands for Universal serial bus, which connects devices like modems, mouses, and keyboards.

What protocol can be applied when you want to transfer files between different platforms, such as UNIX systems and Windows servers?

Use FTP (File Transfer Protocol) for file transfers between such different servers. This is possible because FTP is platform-independent.

What is the use of a VPN?

VPN stands for Virtual Private Network that can be considered as a private Wide Area Network. This network protects anonymity while surfing the internet and accessing certain websites that might be potentially dangerous. It is used in corporate environments where a computer may be connected to a remote server. Traffic on a VPN is sent by creating an encrypted connection over the internet called a tunnel. This provides unauthorized access and eavesdropping over the network.

What is WAN?

WAN stands for Wide Area Network. It is an interconnection of computers and devices that are geographically dispersed. It connects networks that are located in different regions and countries.