Imp Questions.docx

What is telnet ? Telnet is a network protocol used to provide a command line interface for communicating with a device. Telnet is used most often for remote management but is also sometimes used for the initial setup for some devices, especially network hardware like switches, access points, etc.

TFTP ? Stands for "Trivial File Transfer Protocol." TFTP is a file transfer protocol similar to FTP, but is much more limited. Unlike FTP, TFTP does not support authentication and cannot change directories or list directory contents. Therefore, it is most often used to transfer individual files over a local network. TFTP may also be used to boot a computer system from a network-connected storage device. While FTP connections use the TCP protocol, TFTP connections are made over UDP, which requires less overhead than TCP. This means TFTP file transfers may be faster, but less reliable than FTP transfers. Port 20 is used for FTP transfers, while port 69 is used for transferring files via TFTP.

What is an ipaddress ?

1.

An IP address is a numeric identifier assigned to each machine on an IP network. It designates the location of a device on the network.

What is PING utility?

2.

PING – Packet Internet Gopher A utility that verifies connections to one or more remote hosts. The ping command uses the ICMP echo request and echo reply packets to determine whether a particular IP system on a network is functional. Ping is useful for diagnosing IP network or router failures.

3. What is Subnetting? Why is it used? Used in IP Networks to break up larger networks into smaller subnetworks. It is used to reduce network traffic, Optimized network performance, and simplify management i.e. to identify and isolate network problems.

4. Difference between the Communication and Transmission? Communication is the process of sending and receiving data by means of a data cable that is connected externally. Transmission means the transfer of data from the source to the destination.

5. What are 10Base2, 10Base5 and 10BaseT Ethernet LANs? 10Base2 an Ethernet term meaning a maximum transfer rate of 10 Megabits per second that uses baseband signaling, with a contiguous cable segment length of 200 meters (185mts). Known as Thinnet. 10Base5 an Ethernet term meaning a maximum transfer rate of 10 Megabits per second that uses baseband signaling, with a contiguous cable segment length of 500 meters. Known as Thicknet. 10BaseT an Ethernet term meaning a maximum transfer rate of 10 Megabits per second that uses two pairs of twisted-pair baseband signaling, with a contiguous cable segment length of 100 meters.

6. What are the possible ways of data exchange? 1. Simplex 2. Half-duplex 3. Full-duplex

7. What is difference between Baseband and Broadband Transmission? In a baseband transmission, the entire bandwidth of the cable is consumed by a single signal. In broadband transmission, signals are sent on multiple frequencies, allowing multiple signals to be sent simultaneously.

8.

What is Passive Topology?

When the computers on the network simply listen and receive the signal, they are referred to as passive because they don’t amplify the signal in any way.

How Gateway is different from Routers?

9.

Gateway A device connected to multiple physical TCP/IP networks capable of routing or delivering IP packets between them. Router, It’s a layer 3 device that connects 2 different networks and routes packets of data from one network to another. It breaks up Broadcast domain as well as Collision Domain.

What is Brouter?

10.

It’s a Hybrid device that combines the features of both bridges and routers.

11. What is Frame relay, in which layer it comes? ? Frame relay is an industry standard, shared access, switched Data Link Layer encapsulation that services multiple virtual circuits and protocols between connected mechanism. Frame relay is a packet-switched technology..

What is Beaconing?

12.

An FDDI frame or Token Ring frame that points to serious problem with the ring, such as a broken cable. The beacon frame carries the address of the station thought to be down.

13. What is ICMP? It is a Network Layer Internet protocol, which can report errors and status information. We can use the ping command to send ICMP echo request messages and record the receipt of ICMP echo reply messages. With these messages, we can detect network or host communication failures and troubleshoot common TCP/IP connectivity problems.

14. What is difference between ARP and RARP? ARP – Address Resolution Protocol The protocol that traces IP addresses to MAC addresses. RARP – Reverse Address Resolution Protocol The protocol within the TCP/IP stack that maps MAC addresses to IP addresses.

15. What is the difference between TFTP and FTP application layer protocols? TFTP – Trivial File Transfer Protocol A stripped down version of FTP, easy to use and fast. TFTP has no Directory browsing, no Authentication and insecure it can only send and receive files. FTP – File Transfer Protocol The TCP/IP protocol used for transmitting files between network nodes. FTP allows access to both Directories and files, manipulating directories, typing file contents and copying files between hosts.

16. What is logical link control? One of two sublayers of the data link layer of OSI reference model, as defined by the IEEE 802 standard. This sublayer is responsible for error detection but not correction, flow control and framing.

17.

What is Virtual Path? Along any transmission path from a given source to a given destination, a group of virtual circuits can be grouped together into what is called path.

18. What is the difference between interior and exterior neighbor gateways? Interior gateways connect LANs of one organization, whereas exterior gateways connect the organization to the outside world.

19. What is a DNS resource record? A resource record is an entry in a name server's database. There are several types of resource records used, including name-to-address resolution information. Resource records are maintained as ASCII files.

20. Which of the three switching methods is fastest, and why? ICut-Through switching is the fastest method because the switches read only the first six bytes of the frame before forwarding it.

21. What is collision domain ? The network area in Ethernet over which frames that have collided will be detected. Collisions are propagated by hubs and repeaters, but not by LAN switches, routers, or bridges.

26. Explain about Session layer in OSI model? The session layer is responsible for setting up, managing and then tearing down sessions between Presentation Layer entities. This Layer also provides dialog control between devices, or nodes. It coordinates communication between systems and serves to organize their communication by offering there different modes like simplex, half duplex, and full duplex .

27. Explain Presentation layer in OSI model? Presentation layer is a Layer 6 of the OSI reference model, this layer is essentially a translator and provides coding and conversion function. It presents data to the application layer and is responsible for data translation and code formatting. That means it defines how data is formatted, presented, encoded, and converted for use by software at the Application Layer.

28.

Why do we need to subtract two from number of hosts? The hosts part cannot be all one's or all zero's, so these two possibilities are subtracted from the outcome. All one’s reserved for broadcast id and all zero’s are local network. We cannot use this. That’s why we subtract two from the hosts.

Can you explain the concept of VLSM?

29.

Variable Length Subnet Masking - VLSM - is a technique that allows network administrators to divide an IP address space into subnets of different sizes, unlike simple same-size Subnetting. Variable Length Subnet Mask (VLSM) in a way, means subnetting a subnet. To simplify further, VLSM is the breaking down of IP addresses into subnets (multiple levels) and allocating it according to the individual need on a network. It can also be called a classless IP addressing. A classful addressing follows the general rule that has been proven to amount to IP address wastage.

Explain about superneting ?

30.

Supernetting refers to increase host and reduce the subnet's. It mean reduce the network bits and increase the host bits. We do use supernetting because when the PCs in the network increase where we need the more valid IP's in the same network.

31. What is EGP (Exterior Gateway Protocol)? It is the protocol the routers in neighboring autonomous systems use to identify the set of networks that can be reached within or via each autonomous system.

What is Autonomous System?

32.

A group of Networks under mutual administration that share the same routing methodology. Autonomous Systems are subdivided by Areas and must be assigned an individual 16-bit number by the IANA.

33. What is BGP (Border Gateway Protocol)? BGP is a protocol used to advertise the set of networks that can be reached within an autonomous system. BGP enables this information to be shared with the autonomous system. This is newer than EGP (Exterior Gateway Protocol).

34.

What is Kerberos? An authentication mechanism used to verify user or host identity. Kerberos uses encryption to prevent intruders from discovering passwords and gaining unauthorized access to files.

35. What is OSPF (Open Shortest Path First)? OSPF is the first Open Standard Link State Routing Protocol. It's a Classless Routing Protocol meaning when updates are sent they send both IP address and Subnet mask. Administrative Distance is 110. Metric used is Cost i.e. Cost= 108

41. How do Data Link layer addresses and Network addresses differ? Give a description of each. Besides the names suggesting that addresses reside at different layers, other differences do exist. Data Link layer addresses are assigned by the manufacturer and identify the actual hardware device. A Network layer address is a logical address assigned by the network administrator to identify a device running a Network layer protocol, such as IP.

42. What is the difference between interior and exterior neighbor gateways? Interior gateways connect LANs of one organization, whereas exterior gateways connect the organization to the outside world.

What is the HELLO protocol used for?

43.

The HELLO protocol uses time instead of distance to determine optimal routing. It is an alternative to the Routing Information Protocol.

44. What is the difference between routable and non- routable protocols? Routable protocols can work with a router and can be used to build large networks. Non-Routable protocols are designed to work on small, local networks and cannot be used with a router.

45. What is the difference between TFTP and FTP application layer protocols? TFTP – Trivial File Transfer Protocol A stripped down version of FTP, easy to use and fast. TFTP has no Directory browsing, no Authentication and insecure it can only send and receive files.

FTP – File Transfer Protocol The TCP/IP protocol used for transmitting files between network nodes. FTP allows access to both Directories and files, manipulating directories, typing file contents and copying files between hosts.

46. What is difference between ARP and RARP? ARP – Address Resolution Protocol The protocol that traces IP addresses to MAC addresses. RARP – Reverse Address Resolution Protocol The protocol within the TCP/IP stack that maps MAC addresses to IP addresses.

What is ICMP?

47.

ICMP – Internet Control Message Protocol. It is a Network Layer Internet protocol, which can report errors and status information. We can use the ping command to send ICMP echo request messages and record the receipt of ICMP echo reply messages. With these messages, we can detect network or host communication failures and troubleshoot common TCP/IP connectivity problems.

5: What is load balancing? Name four different types of load balancing. A: Load balancing is the process of sending packets over multiple paths to the same destination. Four types of load balancing are: Equal cost, per packet Equal cost, per destination Unequal cost, per packet Unequal cost, per destination 6: What is a distance vector routing protocol? A: A distance vector protocol is a routing protocol in which each router calculates routes based on the routes of its neighbors and then passes its routes to other neighbors. 13: What are the differences between distance vector and link state routing protocols? A: A distance vector router sends its entire route table, but it only sends the table to directly connected neighbors. A link state router sends only information about its directly connected links, but it floods the information throughout the internetworking area. Distance vector protocols usually use a variant of the Bellman-Ford algorithm to calculate routes, and link state protocols usually use a variant of the Dijkstra algorithm to calculate routes. 21: What is the difference between an IGP and an EGP? A: An Interior Gateway Protocol is a routing protocol that routes within an autonomous system. An Exterior Gateway Protocol is a routing protocol that routes between autonomous systems.

10) What are the different memories used in a CISCO router?

- NVRAM stores the startup configuration file - DRAM stores the configuration file that is being executed - Flash Memory – stores the Cisco IOS. 11) What is BootP? BootP is a protocol that is used to boot diskless workstations that are connected to the network. It is short for Boot Program. Diskless workstations also use BootP in order to determine its own IP address as well as the IP address of the server PC. 12) What is the function of the Application Layer in networking? The Application Layer supports the communication components of an application and provides network services to application processes that span beyond the OSI reference model specifications. It also synchonizes applications on the server and client. 13) Differentiate User Mode from Privileged Mode User Mode is used for regular task when using a CISCO router, such as to view system information, connecting to remote devices, and checking the status of the router. On the other hand, privileged mode includes all options that are available for User Mode, plus more. You can use this mode in order to make configurations on the router, including making tests and debugging. 14) What is 100BaseFX? This is Ethernet that makes use of fiber optic cable as the main transmission medium. The 100 stands for 100Mbps, which is the data speed. 15) Differentiate full-duplex from half-duplex. In full-duplex, both the transmitting device and the receiving device can communicate simultaneously, that is, both can be transmitting and receiving at the same time. In the case of half-duplex, a device cannot receive while it is transmitting, and vice versa. 16) What is MTU? MTU stands for Maximum Transmission Unit. It refers to the maximum packet size that can be sent out onto the data line without the need to fragment it. 17) How does cut-through LAN switching work? In Cut-Through LAN switching, as soon as the router receives the data frame, it will immediately send it out again and forward it to the next network segment after reading the destination address. 18) What is latency? Latency is the amount of time delay that measures the point from which a network device receives a data frame to the time it sends it out again towards another network segment. 19) Utilizing RIP, what is the limit when it comes to number of hops?

The maximum limit is 15 hop counts. Anything higher than 15 indicates that the network is considered unreachable. 20) What is a Frame Relay? Frame Relay is a WAN protocol that provides connection-oriented communication by creating and maintaining virtual circuits. It has a high performance rating and operates at the Data Link and Physical Layers. 23) Explain the benefits of VLANs. VLANs allow the creation of collision domains by groups other than just physical location. Using VLANs, it is possible to establish networks by different means, such as by function, type of hardware, protocol, among others. This is a big advantage when compared to conventional LANs wherein collision domains are always tied to physical location. 24) What is subnetting? Subnetting is the process of creating smaller networks from a big parent network. Being a part of a network, each subnet is assigned some additional parameters or identifier to indicate its subnet number. 34) What is Bandwidth? Bandwidth refers to the transmission capacity of a medium. It is a measure of how much volume a transmission channel can handle, and is measured in Kbps. 36) What are packets? Packets are the results of data encapsulation. These are data that has been wrapped under the different protocols of the OSI layers. Packets are also referred to as datagrams 43) What are the different types of passwords used in securing a CISCO router? There are actually five types of passwords that can be used. These are enable secret, enable, virtual terminal, console, and auxiliary.

Network Connection of two or more nodes over the physical media is called as Network.

Networking Connection of two or more nodes over the physical media and sharing the resources is called as Networking.

Types of Network 1.Peer-to-Peer Network

Peer meaning client, Operating system used as client are win95, 98,NT4.0 Workstation, Win2000 prof, ME, XP prof. Workgroup is a small group of computers where no centralized administration and no security is provided. 2.Server based Networks Server is the one that serves the resources to clients. Client is the one that requests for the resources from server. Non-dedicated Server is the system that works both as client and server. Operating system used as server is WinNT 3.51, 4.0, Win2000server, Win2003server. Domain Logical group of computers where centralized administration and security is concerned.

Further Types of Network PAN – Personalized Area Network LAN – Local Area Network CAN – Campus Area Network or BAN – Branch Area Network (within 2km diameter using FDDI) SAN – Storage Area Network MAN – Metropolitan Area Network (takes support of PSTN) WAN – Wide Area Network (takes support of X.25, Frame-relay, ATM, Internet, ISDN) SoAN – Solaris Area Network (network using satellite) WIRELESS INTERNET EXTRANET – Services for employees and customers. INTRANET – Services for employees. LAN Requirements for Networking: Server, Client, NIC, Cable (Media), Switch, Topology, Protocol, Services.