- What is a Link?
A link refers to the connection between two devices. It includes the type of cable and protocols used for one device to communicate with another.
- What are the layers of the OSI reference model?
There are 7 OSI layers: Physical, Data Link, Network, Transport, Session, Presentation, and Application layers.
- What is a backbone network?
A backbone network is a centralized infrastructure designed to distribute different routes and data to various networks. It also handles bandwidth management and various channels.
- What is a LAN?
LAN is the abbreviation for Local Area Network. It refers to the connection between computers and other network devices located in a small physical area.
- What is a node?
A node is a point where a connection occurs. It can be a computer or a device that is part of a network. Two or more nodes are required to form a network connection.
- What is a router?
A router can connect two or more network segments. These are intelligent network devices that store information in their routing tables, such as paths, hop counts, etc. With this information, they can determine the best path for data transmission. Routers operate at the OSI Network Layer.
- 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 require any other network equipment besides connecting a cable to the NIC cards of the two computers.
- What is anonymous FTP?
Anonymous FTP is a way to grant users access to files on public servers. Users allowed to access data on these servers do not need to identify themselves; they log in as an anonymous guest.
- 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 composed of 32 bits.
- What is the maximum allowed length of a UTP cable?
A single segment of UTP cable has an allowed length of 90 to 100 meters. This limitation can be overcome by using repeaters and switches.
- What is data encapsulation?
Data encapsulation is the process of breaking information down into smaller, manageable blocks before transmitting it over a network. In this process, the source and destination addresses are attached to the header along with parity.
- Describe network topology.
Network topology refers to the layout of a computer network. It shows the physical layout of devices and cables, as well as how they are connected to each other.
- What is a VPN?
VPN stands for Virtual Private Network. This technology allows the creation of a secure channel over a network such as the Internet. For example, a VPN allows you to establish a secure dial-up connection to a remote server.
- What is NAT?
NAT is Network Address Translation. It is a protocol that provides a way for multiple computers on a private network to share a single connection to the Internet.
- What is the function of the network layer under the OSI reference model?
The network layer is responsible for data routing, packet switching, and network congestion control. Routers operate under this layer.
- How does network topology affect your decisions when setting up a network?
Network topology determines what medium must be used for interconnected devices. It also serves as the basis for the materials, connectors, and terminations suitable for the setup.
- What is RIP?
RIP, short for Routing Information Protocol, is used by routers to send data from one network to another. It effectively manages routing data by broadcasting its routing table to all other routers on the network. It determines network distance in terms of hop count.
- What are the different ways to secure a computer network?
There are several ways to do this. Install a reliable and updated antivirus program on all computers. Ensure that the firewall is set up and configured correctly. User authentication will also be a great help. The combination of all these will form a highly secure network.
- What is a NIC?
NIC is the abbreviation for Network Interface Card. This is a card connected to a PC to connect to a network. Each NIC has its own MAC address, which is used to identify the PC on the network.
- What is a WAN?
WAN stands for Wide Area Network. It is the interconnection of geographically dispersed computers and devices. It connects networks located in different regions and countries.
- What is the importance of the OSI Physical Layer?
The physical layer performs the conversion from data bits to electrical signals, and vice versa. It is where network devices and cable types are considered and set up.
- How many layers are there under TCP/IP?
There are four layers: Network Access, Internet, Transport, and Application.
- What are proxy servers, and how do they protect a computer network?
Proxy servers primarily prevent external users from identifying the IP addresses of an internal network. Without knowing the correct IP address, one cannot even identify the physical location of the network. Proxy servers can make a network virtually invisible to external users.
- What is the function of the OSI Session Layer?
This layer provides protocols and methods for two devices on a network to communicate with each other by holding a session. This includes setting up the session, managing the exchange of information during the session, and the teardown process when the session terminates.
- What is the importance of implementing a fault-tolerant system? Are there limitations?
A fault-tolerant system ensures continuous data availability. This is achieved by eliminating single points of failure. However, in some cases, this type of system will not be able to protect data, such as with accidental deletion.
- What does 10Base-T mean?
10 refers to the data transfer rate, which is 10Mbps in this case. “Base” refers to baseband. “T” stands for twisted pair, which is the cable used for this network.
- What is a private IP address?
Private IP addresses are assigned for internal networks. These addresses are used within internal networks and cannot be routed on external public networks. They ensure that there are no conflicts between internal networks, while the range of private IP addresses can be reused for multiple internal networks since they do not “see” each other.
- What is a NOS?
NOS, or Network Operating System, is specialized software whose main task is to provide network connectivity to computers so they can communicate with other computers and connected devices.
- What is a DoS?
A DoS, or Denial-of-Service attack, is an attempt to prevent users from accessing the Internet or any other network service. This attack can take different forms and is carried out by a group of perpetrators. A common way to do this is to overload a system server, making it unable to handle legitimate traffic, and it will be forced to reset.
- What is OSI, and what role does it play in computer networking?
OSI (Open Systems Interconnection) serves as a reference model for data communication. It consists of 7 layers, with each layer defining a specific aspect of how network devices connect and communicate with each other. One layer might handle the physical medium used, while another dictates how data is actually transmitted over the network.
- What is the purpose of a shielded and twisted pair cable?
Its main purpose is to prevent crosstalk. Crosstalk is electromagnetic interference or noise that can affect data transmitted through the cable.
- What are the advantages of address sharing?
By using address translation instead of routing, address sharing provides an inherent security advantage. This is because a host on the Internet can only see the public IP address of the external interface on the computer providing address translation, not the private IP addresses on the internal network.
- What is a MAC address?
MAC, or Media Access Control, uniquely identifies a device on a network. It is also known as the physical address or Ethernet address. A MAC address consists of 6 bytes.
- In terms of the OSI reference model, what is the equivalent layer or layers of the TCP/IP application layer?
The TCP/IP application layer actually has three counterparts on the OSI model: the Session, Presentation, and Application layers.
- How do you identify the IP class of a given IP address?
By looking at the first octet of any given IP address, you can identify whether it is Class A, B, or C. If the first octet starts with the bit 0, the address is Class A. If it starts with bits 10, the address is a Class B address. If it starts with 110, then it is a Class C network.
- What is the main purpose of OSPF?
OSPF, or Open Shortest Path First, is a link-state routing protocol that uses a routing table to determine the best path for data exchange.
- What is a firewall?
A firewall is used to protect an internal network from external attacks. These external threats can be hackers who want to steal data or computer viruses that can instantly eliminate data. It can also prevent other users from external networks from accessing the private network.
- Describe a star topology.
A star topology consists of a central hub connected to nodes. This is one of the simplest to set up and maintain.
- What is a gateway?
A gateway provides connectivity between two or more network segments. It is usually a computer running gateway software and providing translation services. This translation is key to allowing different systems to communicate on a network.
- What is a disadvantage of a star topology?
A major disadvantage of a star topology is that once the central hub or switch is damaged, the entire network becomes unusable.
- What is SLIP?
SLIP, or Serial Line Internet Protocol, is an old protocol developed in the early days of UNIX. It is one of the protocols used for remote access.
- Give some examples of private network addresses.
10.0.0.0, with a subnet mask of 255.0.0.0 172.16.0.0, with a subnet mask of 255.240.0.0
- What is tracert?
Tracert is a Windows utility that can be used to trace the route of data packets from a router to a destination network. It also shows the number of hops taken during the entire transmission route.
- What is the role of a network administrator?
A network administrator has many responsibilities, which can be summarized into three key functions: installing the network, configuring network settings, and network maintenance/troubleshooting.
- Describe a disadvantage of a peer-to-peer network.
When you are accessing a resource shared by a workstation on the network, the performance of that workstation decreases.
- What is a hybrid network?
A hybrid network is a network setup that utilizes both client-server and peer-to-peer architectures.
- What is DHCP?
DHCP is the abbreviation for Dynamic Host Configuration Protocol. Its main task is to automatically assign IP addresses to devices on a network. It first checks for the next available address not yet taken by any device and then assigns it to the network device.
- What is the main job of ARP?
The main task of ARP, or Address Resolution Protocol, is to map a known IP address to a MAC layer address.
- What is TCP/IP?
TCP/IP is the abbreviation for Transmission Control Protocol/Internet Protocol. It is a set of protocol layers designed for data exchange on different types of computer networks, also known as heterogeneous networks.
- How can you manage a network using a router?
Routers have a built-in console that allows you to configure different settings, such as security and data logging. You can assign restrictions to computers, such as which resources they are allowed to access or specific times of the day they can browse the internet. You can even impose restrictions on websites that cannot be seen by the entire network.
- What protocol can be applied when you want to transfer files between different platforms, such as a UNIX system and a Windows server?
Use FTP (File Transfer Protocol) for file transfers between these different servers. This is possible because FTP is platform-independent.
- What is the use of a default gateway?
A default gateway provides a way for a local network to connect to an external network. The default gateway used to connect to the external network is usually the address of the external router port.
- One way to protect a network is by using passwords. What can be considered a good password?
A good password is not only composed of letters but also a combination of letters and numbers. Passwords that combine uppercase and lowercase letters are more advantageous than those using all uppercase or all lowercase letters. Passwords must not be easily guessed by hackers, such as dates, names, favorites, and so on.
- What is the correct termination rate for a UTP cable?
The normal termination for an unshielded twisted pair network cable is 100 ohms.
- What is netstat?
Netstat is a command-line utility. It provides useful information about the current TCP/IP settings of a connection.
- What is the number of network IDs in a Class C network?
For a Class C network, the number of available network ID bits is 21. The number of possible network IDs is 2 to the power of 21, or 2,097,152. The number of host IDs per network ID is 2 to the power of 8 minus 2, or 254.
- What happens when you use a cable longer than the specified length?
A cable that is too long will cause signal loss. This means that data transmission and reception will be affected as the signal strength drops.
- What common software problems can cause network defects?
Software-related problems can be any of the following or a combination thereof: Client-server issues, application conflicts, configuration errors, protocol mismatches, security issues, user policy, and rights issues.
- What is ICMP?
ICMP is the Internet Control Message Protocol. It provides messaging and communication for protocols within the TCP/IP protocol stack. It is also the protocol that manages error information used by network tools like PING.
- What is Ping?
Ping is a utility that allows you to check the connectivity between network devices on a network. You can ping a device using its IP address or device name (e.g., computer name).
- What is Peer-to-Peer (P2P)?
Peer-to-peer is a network that does not rely on a server. All PCs on this network are individual workstations.
- What is DNS?
DNS is the Domain Name System. The main function of this network service is to provide hostnames for TCP/IP address resolution.
- What are the advantages of fiber optics over other media?
A major advantage of fiber optics is that it is less susceptible to electrical interference. It also supports higher bandwidth, meaning more data can be sent and received. Signal degradation over long distances is also very small.
- What is the difference between a hub and a switch?
A hub acts as a multi-port repeater. However, as more devices connect to it, it will not be able to efficiently manage the traffic passing through it. A switch provides a better alternative and can improve performance, especially when high traffic is expected on all ports.
- What are the different network protocols supported by Windows RRAS service?
Three main network protocols are supported: NetBEUI, TCP/IP, and IPX.
- What are the maximum number of networks and hosts in Class A, B, and C networks?
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 standard color order for a straight-through cable?
Orange/white, orange, green/white, blue, blue/white, green, brown/white, brown.
- What protocols fall under the application layer of the TCP/IP protocol stack?
The following are TCP/IP application layer protocols: FTP, TFTP, Telnet, and SMTP.
- You need to connect two computers for file sharing. Is it possible to do this without using a hub or router?
Yes, you can connect two computers together with a single cable. A crossover cable can be used in this case. In this setup, the data transmission pins of one cable are connected to the data receiving pins of the other, and vice versa.
- What is ipconfig?
Ipconfig is a utility commonly used to identify the address information of a computer on a network. It can display both the physical address and the IP address.
- What is the difference between a straight-through and a crossover cable?
A straight-through cable is used to connect a computer to a switch, hub, or router. A crossover cable is used to connect two similar devices together, such as PC to PC or hub to hub.
- What is client/server?
Client/server is a type of network where one or more computers act as servers. The server provides a centralized repository of resources, such as printers and files. A client refers to a workstation that accesses the server.
- Describe a network.
A network refers to the interconnection between computers and peripheral devices used for data communication. Network connections can be made using wired cables or through wireless links.
- When you move a NIC card from one PC to another, is the MAC address also transferred?
Yes, that is because the MAC address is hard-wired to the NIC circuit, not the PC. This also means that a PC can have a different MAC address when the NIC card is replaced with another one.
- 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 that in case of a server failure, the next server in the cluster will continue all processing.
- In a network containing two servers and twenty workstations, where is the best place to install an antivirus program?
An antivirus program must be installed on all servers and workstations to ensure protection. This is because an individual user can access any workstation and introduce a computer virus when inserting a removable hard drive or flash drive.
- Describe Ethernet.
Ethernet is one of the popular network technologies used today. It was developed in the early 1970s and is based on the specifications outlined in the IEEE. Ethernet is used in local area networks.
- What are the disadvantages of implementing a ring topology?
If a workstation on the network fails, it can cause the entire network to be lost. Another disadvantage is that when adjustments and reconfigurations are needed on a specific part of the network, the entire network must also be temporarily shut down.
- What is the difference between CSMA/CD and CSMA/CA?
CSMA/CD, or Collision Detection, retransmits the data frame whenever a collision occurs. CSMA/CA, or Collision Avoidance, will first broadcast the intention to send data before transmission.
- What is SMTP?
SMTP is the abbreviation for Simple Mail Transfer Protocol. This protocol handles all internal mail and provides the necessary mail delivery services on the TCP/IP protocol stack.
- What is multicast routing?
Multicast routing is a targeted form of broadcasting that sends messages to a selected group of users, rather than sending it to all users on a subnet.
- What is the importance of encryption on a network?
Encryption is the process of converting information into an unreadable code for users. It is then translated or decrypted back to its normal readable format using a secret key or password. Encryption helps ensure that information intercepted midway remains unreadable, as the user must have the correct password or key.
- How are IP addresses organized and displayed?
An IP address is displayed as a series of four-digit decimal numbers separated by periods or dots. Another term for this arrangement is dot-decimal notation. An example is 192.168.101.2.
- Explain the importance of authentication.
Authentication is the process of verifying a user’s credentials before they can log in to a network. It is typically done with a username and password. This provides a secure means of restricting access from harmful intruders on the network.
- What does tunnel mode mean?
This is a data exchange mode where the two communicating computers themselves do not use IPSec. Instead, the gateways connecting the LANs to the transit network create a virtual tunnel that uses the IPSec protocol to secure all communication passing through it.
- What are the different technologies involved in establishing a WAN link?
Analog connection - uses regular telephone lines; Digital connection - uses digital telephone lines; Switched connection - uses multiple sets of links between the sender and receiver to move data.
- What is an advantage of a mesh topology?
In the event that one link fails, there will always be another link available. A mesh topology is actually one of the most fault-tolerant network topologies.
- When troubleshooting a computer network, what are some common hardware-related problems that might occur?
Most of a network is composed of hardware. Issues in these areas can include hard drive failure, NIC damage, or even hardware startup issues. Incorrect hardware configuration is also a common troubleshooting problem.
- What can be done to fix signal attenuation problems?
A common way to deal with this problem is to use repeaters and hubs, as they help to regenerate the signal and thus prevent signal loss. Checking that the cables are properly terminated is also a must.
- How does the Dynamic Host Configuration Protocol assist in network management?
Instead of a network administrator having to visit each client computer to configure a static IP address, they can apply the Dynamic Host Configuration Protocol to create a pool of IP addresses called a scope that can be dynamically assigned to clients.
- Explain the concept of a network profile.
A profile is a set of configuration settings for each user. For example, a profile can be created to place users into groups.
- What is Sneakernet?
Sneakernet is considered the earliest form of networking, where data is physically transported using removable media such as disks or tapes.
- What is the role of the IEEE in computer networking?
The IEEE, or Institute of Electrical and Electronics Engineers, is an organization of engineers that sets and manages standards for electrical and electronic equipment. This includes network devices, network interfaces, cables, and connectors.
- What protocols are under the TCP/IP Internet layer?
This layer manages four types of protocols: ICMP, IGMP, IP, and ARP.
- What are permissions in networking?
Permissions refer to the authorized licenses to perform specific actions on a network. Each user on the network can be assigned individual permissions, depending on what that user must be allowed to do.
- What is a basic requirement for establishing a VLAN?
A VLAN is needed because at the switch level there is only one broadcast domain, which means that whenever a new user connects, that information is propagated to the entire network. A VLAN on a switch helps to create separate broadcast domains at the switch level. It is used for security purposes.
- What is IPv6?
IPv6, or Internet Protocol version 6, was developed to replace IPv4. Currently, IPv4 is used to control Internet traffic, but IPv4 has become saturated. IPv6 is able to overcome this limitation.
- What is the RSA algorithm?
RSA is the abbreviation for the Rivest-Shamir-Adleman algorithm. It is currently the most commonly used public-key encryption algorithm.
- What is a mesh topology?
A mesh topology is a setup where every device is directly connected to every other device on the network. Therefore, it requires each device to have at least two network connections.
- What is the maximum segment length for a 100Base-FX network?
The maximum allowed length of a network segment using 100Base-FX is 412 meters. The maximum length of the entire network is 5 kilometers.