Networking Short Questions/Short Answers (Good for CISCO Students)

What is PING utility?

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.

What is a VLAN? What does VLAN provide?

VLAN – Virtual Local Area Network

Vlan is a logical grouping or segmenting a network connected to administratively defined ports on a switch, they provide Broadcast control, Security and Flexibility.

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.

What is RAID?

A method used to standardize and categorize fault-tolerant disk systems. RAID levels provide various mixes of performance, reliability, and cost. Some servers provide three of the RAID levels: Level 0 (striping), Level 1 (mirroring), and Level 5 (striping & parity).

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.

What are the two types of Transmission Technology available? Point  to  Point and Broadcast

What is point-to-point protocol?

An industry standard suite of protocols for the use of point-to-point links to transport multi protocol datagrams.

What are the possible ways of data exchange?

Simplex Half-duplex Full-duplex

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.

What are major types of Networks and explain?

Peer-to-Peer Network Computers can act as both servers sharing resources and as clients using the resources. Server-based Network

Provide centralized control of network resources and rely on server computers to provide security and network administration

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.

What is Mesh Network?

A network in which there are multiple network links between computers to provide multiple paths for data to travel.

How Gateway is different from Routers?

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?

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

What is Subnet?

A subdivision of an IP network.

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 Terminal Emulation, in which layer it comes?

The use of software, installed on PC or LAN server, that allows the PC to function as if it were dumb terminal directly attached to a particular type of mainframe.  Telnet is also called as terminal emulation. It belongs to application layer.

What is Beaconing?

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.

 What are NetBIOS and NetBEUI?

NetBIOS – Network Basic Input / Output System

An application-programming interface (API) that can be used by programs on a local area network (LAN). NetBIOS provides programs with a uniform set of commands for requesting the lower-level services required to manage names, conduct sessions, and send datagrams between nodes on a network.

NetBEUI – NetBIOS Extended User Interface

An improved version of the NetBIOS protocol, a network protocol native to Microsoft Networking. It is usually used in small, department-size local area networks (LANs) of 1 to 200 clients. It can use Token Ring source routing as its only method of routing.

What is Cladding?

A layer of a glass surrounding the center fiber of glass inside a fiber-optic cable.

What is Attenuation?

In communication weakening or loss of signal energy, typically caused by distance.

What is MAC address?

The address for a device as it is identified at the Media Access Control (MAC) layer in the network architecture. MAC address is usually stored in ROM on the network adapter card and is unique.

What is ICMP? 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.

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 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.

What is MAU?

MAU – Multistation Access Unit 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.

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.

What is Virtual Channel?

A logical circuit that is created by Virtual channel links. It carries data between two endpoints in a network.  The other name for Virtual Channel is Virtual Circuit.

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.

What is Packet Filter? What is multicast routing?

Sending a message to a group multicast address is called multicasting, and its routing algorithm is called multicast routing.

What is IGP (Interior Gateway Protocol)?

Any protocol used by an internetwork to exchange routing data within an autonomous system. E.g. RIP, IGRP and OSPF.

 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?

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.

What is BGP (Border Gateway Protocol)?

It 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).

What is Gateway-to-Gateway protocol?

It is a protocol formerly used to exchange routing information between Internet core routers.

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.

What is SLIP (Serial Line Internet Protocol)?

An industry standard serial encapsulation for point-to-point connections that supports only a single routed protocol, TCP/IP.

What is the HELLO protocol used for?

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

 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 protocol do DNS name servers use?

DNS uses UDP for communication between servers. It offers a connectionless datagram service that guarantees neither delivery nor correct sequencing of delivered packets (much like IP).

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.

BOOTP helps a diskless workstation boot. How does it get a message to the network looking for its ip address?

A protocol used primarily on TCP/IP networks to configure diskless workstations. BOOTP sends a UDP message with a subnetwork broadcast address and waits for a reply from a server that gives it the IP address.

What is anonymous FTP and why would you use it?

Anonymous FTP enables users to connect to a host without using a valid login and password. Usually, anonymous FTP uses a login called anonymous or guest, with the password usually requesting the user’s ID for tracking purposes only. Anonymous FTP is used to enable a large number of users to access files.

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.

What are the differences or similarities, if any, between repeaters, hubs, and concentrators?

First, they are all Physical layer devices. Repeaters regenerate and amplify the signal traveling on the wire to extend the normal distance limitation of the signal. A repeater can connect two network segments. A hub and a concentrator are the same thing, with hub being the more common term used today. Hubs are repeaters with 8–24 ports. When one machine attached to the hub sends anything over the network, all the devices attached to the hub receive that signal.

Describe, in general terms, the reasons for implementing LAN segmentation.

It confines user traffic to a segment and addresses and solves distance limitation problems. Segmentation also cuts down on the traffic generated by broadcasts and multicasts, and thereby increases performance. Because of the reduction of the size of the segment, collisions and overall traffic also are reduced.

Which of the three switching methods is fastest, and why?

Cut-Through switching is the fastest method because the switches read only the first six bytes of the frame before forwarding it.

What services do bridges and switches provide?

Bridges and switches can determine whether a frame is destined for the local network segment or needs to be forwarded to another network segment based on the destination MAC address.