Q10.Which of the following is the standard adopted for Ethernet CSMA/CD by IEEE Committee?

          A.   802.2
          B.   802.3
          C.   802.1d
          D.   802.5
Answer / Explanation: B

IEEE 802.1d defines Spanning-Tree Protocol (STP), a link management protocol that provides path redundancy while preventing undesirable loops in a network consisting of bridges or layer-2 switches. STP ensures that there are no loops and maintains data on available backup paths in the event the primary path becomes unreachable.
IEEE 802.2 standard corresponds to Logic Link Control (LLC) and specifies an implementation of the LLC sublayer of the data link layer. IEEE 802.2 LLC is used in IEEE802.3 (Ethernet) and IEEE802.5 (Token Ring).
802.3 is a standard specification for Ethernet, and specifies the physical media and the working characteristics of Ethernet.
IEEE 802.5 defines Token ring LAN protocol where all stations are connected in a ring and each station can directly hear transmissions only from its immediate neighbor. Permission to transmit is granted by a message (token) that circulates around the ring.

Q9.Which of the following are routing protocols?

         A.   RIP,TCP
         B.   TCP,OSPF
         C.   OSPF,IP
         D.   RIP,OSPF
Answer / Explanation:  D

RIP,OSPF / Routing protocols job is to maintain routing tables and route packets appropriately. Examples of routing protocols are RIP, IGRP,EIGRP,OSPF. Routers can support multiple independent routing protocols and can update and maintain routing tables for each protocol independently.Routed protocols are used to transport user traffic from source node to destination node. Examples of routed protocols are IP, IPX, AppleTalk.

Q8.Which parameter uniquely identifies a wireless network?

       A.   IP address
       B.   MAC address
       C.   SSID
       D.   Network number
Answer / Explanation:  C

SSID (short for Service Set IDentifier) is a 32-character unique identifier attached to the header of packets when a host connects to a Wireless LAN. The SSID differentiates one WLAN (short for Wireless LAN) from another, so all access points and all devices attempting to connect to a specific WLAN must use the same SSID. An SSID is also referred to as a network name because essentially it is a name that identifies a wireless network.
IP address is a logical address and used for routing packets over an IP network. MAC address is assigned to the NIC (Network Interface Card), which sits on a workstation (host) and connects to a LAN, and identifies the resource physically. Network number is not a relevant option.

Q7.Match the following:

      A. Repeaters       1. Data Link Layer
      B. Bridges            2. Network Layer
      C. Routers           3. Physical Layer

    a)    A --->2, B--->3, C--->1
    b)    A--->3, B---->1, C---->2
    c)    A--->3,B----->2, C---->1
    d)    A---->1, B---->2, C---->3

Answer / Explanation:   b

The most frequently used network devices may be categorized as repeaters, hubs, switches, and routers. These devices let you connect computers, printers, and other devices to communicate with each other.The medium that is used for communication is usually cable (optical or copper) and air (Wifi, bluetooth, etc.).
A repeater is a basic device that simply amplifies the input signals and retransmits. It is used to extend the range of a network segment.
For example, the range of a 10BaseT network segment is 100meters by default.If the end devices are at a distance more than 100 meters, you will require a repeater so that the transmitted signals are received at the destination device without losing any information.
A bridge/switch essentially forwards the frames that come from one port to other ports.A switch is used to connect two or more network segments. A switch learns the physical addresses of sending devices by reading the MAC address and mapping it to the port number through which the frame had arrived.
This way, it will quickly learn which MAC address belongs to which switch port, and stores the information in a table (called MAC table). Then onwards, it will send aframe only to the port that connects to the destination device (as specified in the frame). MAC addressesare layer-2 addresses. Because a switch works on MAC addresses, we can classify switches as Layer-2 devices.
A router is used to route packets by connecting two or more networks together.They work at layer-3 of the OSI model.They route packets based on the IP addresses where as a switch forwards packets based on the MAC addresses. A router needs to disseminate an incoming packet down to its IP address and route it to destination based on information available in its routing table.
Switches maintain a MAC table where as routers maintain a routing table. When a switch sends a packet (usually called a frame when sent by a switch) it iscalled forwarding.A router reads the destination IP address of the incoming packet, finds out which interface it needs to go to reach desired destination (which may be several hops away) and routes the packet appropriately.

Q6.Which utility should be used for copying files from a UNIX computer to your Windows computer working as client?
   
      A.   NFS
      B.   NTP
      C.   FTP
      D.   Telnet
Answer / Explanation: C

In OSI model, applications work at the top layer, called Applications Layer. Some of the applications layer protocols are NFS, NTP, FTP, and Telnet.
NFS (Short for Network File System): NFS allows a system to share directories and files with others over a network. By using NFS, users and programs can access files on remote systems almost as if they were local files.
NTP (Short for Network Time Protocol): NTP is an Internet protocol used to synchronize the clocks of computers to some time reference.
FTP: (Short for File Transfer Protocol): FTP is a protocol used to copy a file from one host to another over a TCP/IP-based network, such as the Internet. FTP is used with user-based password authentication or with anonymous user access.
Telnet: Telnet is a TCP/IP protocol used to connect to a server using a remote terminal over a network such as Internet or intranet. You work with a remote server as if you are directly connected. In other words, Telnet is a terminal emulation protocol that enables remote access to server resources.
One thing common with all these protocols are that they are built on client-server architecture and utilizes separate control and data connections between the client and server applications, which solves the problem of different end host configurations (i.e., Operating System, file names).

Q5.What is the core administrative unit in Domain Name System (DNS) is called?

         A.   matrix
         B.   zone
         C.   domain
         D.   com
Answer / Explanation: B

The core administrative unit in DNS is called 'zone'. A zone is a physical file composed of resource records that define one or more domains. A domain is a node in the DNS namespace and all sub-domains below it.
In other words, a zone file is a text file that describes a hierarchical node of the Domain Name System (DNS) called a DNS zone. In a DNS Zone file, each line can hold only one record, and each DNS Zone file must start with the TTL (Time to Live), which specifies for how long the records should be kept in the DNS Server's cache. The other mandatory record for a DNS Zone file is the SOA (Start of Authority) record - it specifies the primary authoritative name server for the DNS Zone. Each line typically defines a single resource record.
A line begins with a domain name, but if left blank, defaults to the previously defined domain name. Following the domain name is the TTL, the class (which is almost always 'IN' for 'internet' and rarely included), the type of resource record (RR, such as A, MX, SOA, etc.), followed by type-specific data such as the IPv4 address for A records. Comments can be included by using a semicolon and lines can be continued by using parenthesis.

An example DNS file is given below:
$ORIGIN mydomain.com. ; designates the start of this zone file in the name space
$TTL 1h ; The default expiration time of a resource record without its own TTL value
mydomain.com. IN SOA ns.mydomain.com. root.mydomain.com. (
2008120710 ; serial number of this zone file
1d ; slave refresh (1 day)
1d ; slave retry time in case of a problem (1 day)
4w ; slave expiration time (4 weeks)
1h ; minimum caching time in case of failed lookups (1 hour) )

mydomain.com. NS dns1.hosting.com. ; ns.mydomain.com is the nameserver for example.com
mydomain.com. NS dns2.hosting.com. ; dns2.hosting.com is a backup nameserver for example.com
mydomain.com. MX 10 mx1.hosting.com; mail.example.com is the mailserver for mydomain.com
mydomain.com. A 209.25.134.47 ; ip address for 'mydomain.com'

Q4.Which of the following is a multicast address (Class D)?

         A.   127.0.0.1
         B.   10.10.19.1
         C.   226.12.14.112
         D.   204.16.1.36
Answer / Explanation: C

226.12.14.112/ The range of numbers from 224.0.0.0 to 239.255.255.255 is used for multicast packets. This is known as Class D address range.

Q3.What is the directed broadcast address for an IP network 196.233.24.15 with default subnet mask?

     A.   196.233.255.255
     B.   196.255.255.255
     C.   196.0.0.0
     D.   196.233.24.255
Answer / Explanation: D

196.233.24.255/ This is a Class C network with default subnet mask, which is 255.255.255.0. The directed broadcast should reach all Hosts on the intended network (or subnet, if subnetted). Therefore, by putting all 1s for the host potion of the IP address, we get 196.233.24.255.

Q2.Which of the following is a Class B network address?

    A.   19.155.26.22
    B.   127.0.0.1
    C.   128.23.44.22
    D.   196.202.202.35
Answer / Explanation: C

IP addresses are written using decimal numbers separated by decimal points. This is called dotted decimal notation of expressing IP addresses. The different classes of IP addresses as per IP v4 specification is as below:

Class    Format       Leading Bits       Network address       Max.nets         Max hosts
A          N.H.H.H           0                        0 - 126                      127             16,777,214
B          N.N.H.H          10                     128 - 191                   16,384              65,534
C          N.N.N.H          110                  192 - 223                 2,097,152              254
D      Not Applicable    1110      Address range:  224.0.0.0 to 239.255.255.255   (Class D multicast address space is 2^28  or 268,435,456 multicast groups.)
E     Not Applicable    1111       Address range: 240.0.0.0     255.255.255.255

Network address of all zeros means  'This network or segment'.
Network address of all 1s means 'all networks', same as hexadecimal of all Fs.
Network number 127 is reserved for loop back tests.
Host (Node) address of all zeros mean 'This Host (Node)'.
Host (Node) address of all 1s mean 'all Hosts (Nodes)' on the specified network.
Class D is a special multicast address and cannot be used for networks. The 4 high-order bits are always 1110, and the remaining 28 bits allow for more than 268 million possible addresses. There is no concept of network and host address ranges in Class D. Class E is reserved for experimental purposes. The first four bits in the address are always 1111.

Q1. You are Telnetting to a remote host on the Internet. Which protocol is being used?

    A.     UDP
    B.     TCP
    C.     HTTP
    D.     FTP
Answer / Explanation: B

The Telnet program is an OSI Application Layer protocol that runs on your computer and connects your PC (a client) to a server on the network. You can then enter commands through the Telnet program and they will be executed as if you were entering them directly on the server console. This enables you to configure and control the server resources remotely.

Other application layer (Layer 7 of OSI) protocols include Network Time Protocol (NTP),Simple Network Management Protocol (SNMP), and File Transfer Protocol (FTP).

Note that the application layer protocols may use TCP or UDP for communication with peers. For example,FTP and Telnet use TCP where as Trivial File Transfer Protocol (TFTP) uses UDP.

HTTP is also an example of Application layer protocol that uses TCP for communicating.

Q10. What is the default subnet mask for Class C network?

     A.      255.0.0.0
     B.      255.255.0.0
     C.      255.255.255.0
     D.      255.0.255.0

Correct Answer: C.

Explanation:

The default subnet mask for

Class A network: 255.0.0.0

Class B network: 255.255.0.0

Class C network: 255.255.255.0

Q9. Which of the following is suitable for mission critical and time sensitive applications?

                 A.      10BaseT
                 B.      10Base2
                 C.      Token Ring
                 D.      Mesh

Correct Answer: C.

Explanation:

Token Ring is most suitable for mission critical applications as it would guarantee the time slot for every work station on the ring. If required, the station priorities can be set.

Q8. Which type of connector does a 10BaseT Ethernet cable use?

                A. BNC
                B. RJ-45
                C. RJ-11
                D. MSAU

Correct Answer: B.

Explanation:

10BaseT Ethernet uses RJ-45 connectors at the ends of the UTP cable.

10Base2 Ethernet uses BNC connectors at the ends of the Thinnet (Coax) cable.

Q7. Which of the following media types is most susceptible to EMI?

            A.      Fiber Optic
            B.      STP
            C.      Co-axial
            D.      UTP

Correct Answer: D.

Explanation:

UTP stands for Un-shielded Twisted Pair cabling. STP for Shielded Twisted Pair cabling. UTP cabling is most susceptible for EMI. Fiber Optic is least susceptible.

Q6.     Disk Striping with Parity corresponds to which RAID level?

                 A.      RAID 0
                 B.      RAID 1
                 C.      RAID 3
                 D.      RAID 5

Correct Answer: D.

Explanation: RAID stands for Redundant Array of Inexpensive Disks.

Most widely used RAID levels are:

RAID 0: Disk Striping

RAID 1: Disk Mirroring

RAID 5: Disk Striping with Parity

WIndows NT supports RAID levels 0,1, and 5.