Most computers are connected to a particular network. A computer that isn’t linked to any network is hardly better than a chunk of metal and plastic these days. What we mean by the term “network” is the connection shared by multiple computers under protocols that offer information as needed. Networking as a subject is growing by leaps and bounds and has become a staple in interviews. IT candidates face numerous networking questions, whether it be for the position of programmer or system administrator. And we’re here to guide you on this demanding topic, making sure you develop the fundamental knowledge of networking and networks to answer the most likely networking interview questions you will face.
Can you tell me what DNS means?
DNS, short for domain name server, may be regarded as the phone book of the Internet. All public IP addresses as well as their hostnames get stored in the DNS and it then translates to corresponding IP addresses. People can easily recognize and remember domain names. But for computers, only the language of IP addresses used for data transfer gets recognized. There’s a central registry where all domain names are stored and it is periodically updated. All Internet service providers and the various host companies normally interact with this central registry for knowing the updated domain name server details.
Can you explain the OSI Reference Model?
OSI stands for Open System Interconnection. The name itself is indicative of a reference model that defines the way apps communicate with one another over a networking system. It is also helpful in understanding the connection between networks and defines the communication process in a particular network.
The OSI Reference Model is comprised of seven layers:
- Physical Layer: This is the first layer, responsible for converting data bits into radio signals or electrical impulses.
- Data Link Layers: The second layer is where data packets are decoded and encoded into bits. Layer 2 offers a node to node data transfer and even detects any errors taking place in the first layer.
- Network Layer: The third layer is the Network Layer where data sequences of variable lengths get transferred from one node to the other within the same network. The variable length data sequences are commonly called Datagrams.
- Transport Layer: The fourth layer is responsible for transferring data between nodes and even offers acknowledgement of successful data transmission. This transmission gets traced and the segment is sent once more if the transmission does not go through successfully.
- Session Layer: The fifth or Session Layer controls and manages the connections between computers. It is tasked with exchanging, coordinating, and terminating the connections between remote and local applications.
- Presentation Layer: Also known as the Syntax Layer, the sixth layer converts data into a form that is accepted by the Application Layer.
- Application Layer: The final layer of the OSI Reference Model, this seventh layer is the closest to the end user. Both this layer and the end user interact with the software application, and it is responsible for offering services like file transfer and email.
What do you know about IPv4 vs. IPv6?
Both of them are Internet Protocol versions. The IP address happens to be a unique value representative of a device over a specific network. Every device over the Internet needs to have an address that is unique and valid for even the normal functions. IPv4 is a 32-bit numeric indicator of Internet devices that are widely used, supporting nearly 4.3 billion separate IP addresses. Given the constant growth of the Internet and devices, a new version — IPv6 — was released that can support greater numbers of users. IPv6 represents a 128-bit numeric version of Internet devices and supports 340 trillion, trillion, trillion distinct IP addresses. This is enough to provide all humans on the planet with unique IP addresses.
What does a firewall consist of?
A firewall is a network security system that’s used for protecting computer systems from unauthorized access. It prevents access from external malicious sources to the network. Firewalls also grant limited access to users from the outside. A firewall normally consists of a software program, a hardware device, or a combination of both. Every message routed through a firewall gets examined by a particular security criteria and the messages that meet this criteria are successfully passed through the network. Otherwise, they get blocked.
What is POP3?
The popular IT term “POP3” is short for Post Office Protocol Version3 (Current Version). This happens to be a protocol connected to port 110 that accesses the mail program located on a client’s system. POP3 has two different modes — Keep Mode and Delete Mode. When in Keep Mode, all the mail stays intact once it is retrieved successfully. In Delete Mode, it gets deleted from the mailbox upon being retrieved successfully.
How is network reliability commonly checked?
To measure network reliability, you must usually consider the following factors:
- Downtime, which is the recovery time necessary.
- Failure frequency, which refers to the frequency at which it does not function in the intended way.
What are the purpose and function of routers?
The router is a network device that connects two or more segments of the same network. The router is used for transferring information from the source to the intended destination. Routers transmit information in data packets and once these data packets have been forwarded from a particular router to another one, the destination router reads the network address mentioned in the packets and recognizes the destination network.
For what purpose is a standard and cross-cable used?
Network cables may be crossover or straight. These two kinds of cables have separate wire arrangements that serve to fulfill different purposes. While straight cables are used to connect the switch to computer, router to switch, hub to computer, and modem to computer, a crossover cable is used to connect one computer to the other, hub to hub, and switch to switch.
What is HTTPS and how does it differ from HTTP?
HTTPS is a secure HTTP for safe communication over a computer network. HTTPS offers authentication of sites to prevent unwanted attacks.
What is meant by bandwidth?
Each signal possesses an upper limit and a lower frequency range that it is able to carry. This limit range is known as bandwidth.
Acing your networking interview
Acing a networking interview isn’t tough once you prepare the right questions. And the questions mentioned above are the most common ones you need to know for having a solid career in IT.
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