Network administrator has a prominent role to playin the company where he works. He is responsible to look after the network related problems and troubleshoot them. The applicant desiring to work as network administrator needs toacquire bachelor’s degree in computer applications. And after acquiring the certificate, they need to undergo a networking course where they are taught with the basic networking concepts. The applicant must be well prepared to clear the interview and get placed in a well reputed company. Due to rise in the number of companies, the demand fornetwork administrator has increased rapidly. The individual applying for the position of the network administrator need to have the basic knowledge of network related concepts. The questions that are asked by the recruiter for the role of network administrator are given below.
1. What are the seven layers of the OSI model?
The abbreviation for OSI is open system interconnection and it is the standard model used for developing networks and to implementprotocols. The seven layers in the OSI model are given below.
- Application layer: it isused as an interface between the user and network. And in this layer messages are stored in the messages form.
- Presentation layer: the format in which the data is transferred is negotiatedin this layer and the data is sent assegments.
- Session layer: the connection in this layer can be establishedby the name of the network and the data is transferred in form of segments.
- Transport layer: it is used for end to end transfer of data between two systems. And the data transfer is done in segments form.
- Network layer: this layer is mainly used for routing data through the large networks. And the data transfer or storage is done in packets.
- Data link layer:this layer is used for gaining access to network media. The data transfer is down in frames form.
- Physical layer: at this layer, the messages of the data link layer that are in frame form are converted into bits.
2. Whatare subnet mask, MAC address and IP address?
Subnet mask: it is generally usedto find the number of hosts and networks.Every IP address of the system use different subnet masks and these subnet masks are used in dividing the IP networks into several sub networks for improving the performance of the system and to ensurehigh level security.
MAC address:Media access control is used as unique identifier to find the computer device. Usually the MAC address is given by the manufacturer. It is a 12 digit hexadecimal number used for identifying the device.
IP address: this unique address is used for identifying the networking device that is available on the LAN (local are network), WAN (wide area network). Every computer need to have aunique internet protocol address and this IP address is given by the local internet service providers through which the user establishes internetconnection.
3.What are the various types of networking devices?
There are several types of networking device that are used for establishing connection.
- Repeater: it is also called as regenerator. This device is usedonly in physical layer. The role of the repeater is to receive the signals before it gets weakened. This device regenerates original pattern of bitsand places it back in the link.
- Bridges: these devices are usedin both the physical layer and datalinklayer. Theyare mainly used for dividing alarge network into small segments. They contain the logical that is useful to keep the traffic of each segment separately.
- Routers: they are used for relaying the packets among several interconnected networks. They usually operate in the physical layer, datalink layer and network layers.These routers contain software that enables them find out thebest path for data transmissionamong several paths.
- Gateways: they are used for transferring packets among networks with different protocols. They accept the packetof one protocol type and convert it to packet of other protocol type before transmitting it. They are used in all the layers of the OSI model.
4. What are the various network topologies?
- BUS topology: in this topology type, each computer is connected directly toa network cable in single line. It is inexpensive, installation is simple, easy to understand and extend it.
- STAR topology: in this topology, all the computers are directly connected to central hub. The cost needed for establishing connection using this topology is very less. It is simple to install, reconfigure and easy to resolve the physical problems.
- RING topology: in this model, all the computers are connectedin the loop form. All computersin topology can have equal access to the network media, they can be installed simply. The signal doesn’t get down when compared with other topology types.
5.What is ICMP?
The abbreviation for the ICMP is internet control message protocol. It is networklayer protocol that belongs to TCP/IP suite and it is used by the gateway to send the notifications relatedto datagram problems to the sender. It is also used for the echo test, a test that is conducted to check whether the destination is reachable or not.
6. What is meant by middleware?
Middleware is software that is used for establishing good communication between the clients and servers. It is similar toa type of bridgethat is used in establishing network connections. The application of the clientsideinvokes the services and theyare managedby the middleware. The middleware doesnot have any additional software to carryout its operations.
7.What is VOIPTechnology?
VOIP stands for voice over internet protocol. This VOIP technology is used for the transmitting the voice over long networks to make calls. VOIP phone calls are of less cost and in presentworld many corporate offices are using this VOIP technology formaking phone calls over long distances.
The abbreviation for DHCP is dynamic host configuration technology. The main purpose of the DHCP is to assign the IP address and other network relatedconfigurations that include DNS,Gateway,subnet mask and other settingsthatare required for establishing internet connection. DHCP is used widelyas it reduces the manual work of the administrators to assign IP address to every client in case of large number of networks.
9. Define DNS and explain how it works?
DNS is used to translate the IP address into host name so that it becomes easy for the user to remember the host name and it converts host name into IP address. Every domain and deviceisassigned with unique IP addresses and these addresses are used for identifying the device and to establish connection with the internet.
10. What is firewall?
Firewall ispresent in every network and it acts as protective boundary for the network. It prevents the network from unauthorizedusers. Many operating systems have built-in firewalls. The third party software’sare plenty in number that provides firewall to protect the computer or network from the hackers.
11.What is the difference between TCP and UDP?
TCP (transmission control protocol) is the popular internet standard protocol that is used for establishing network connection to the computer. Every internet browser uses this protocol to get connected to the server. This protocol receives the request from the user and transfer’s it to the HTML. This TCP protocol is inbuilt in manyoperating systems. The TCP protocol is used for the long time connection. The communication layer and physical of the OSI standard model uses this protocol.
UDP(user datagram protocol) is a connectionless protocol that is mainly used for transferring messages without any errors. The user can send short service messages over the internet and the messages are termed datagrams.
12. What is Wi Max technology and GSM technology?
Wi Max is the advanced version of the Wi-Fi wireless technology. It supports data, audio and video communication at same time and the minimum speed is 70mbps.
GSM technology is wireless technology that can be usedwith in short range and it is mostly used in the mobiles, MP3 devices, Laptops and computers.
13.What are VPN’s?
Virtual private networks (VPN) are the logical networks that are available on the same physical line. These networks are mainly used when the individual desires to increase the connection but doesn’t want to buy any new switches.
14.What are the uses of VLAN?
VLAN (virtual local area networks) are used for enhancing the network security. They also increase the broadcast domains by decreasing the domain size. A network can be added, moved, changed by configuring the appropriate port.