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Right CHOICE is (b) 8 subnets, 8,190 hosts each

For explanation: A CIDR ADDRESS of /19 is 255.255.224.0. This is a Class B address, so that is only 3 subnet BITS, but it PROVIDES 13 host bits, or 8 subnets, each with 8,190 hosts.

Right ANSWER is (c) 172.16.64.0

Easiest explanation: A /21 is 255.255.248.0, which means we have a block SIZE of 8 in the third octet, so we just count by 8 until we reach 66. The SUBNET in this question is 64.0. The next subnet is 72.0, so the BROADCAST address of the 64 subnet is 71.255.

Correct choice is (a) 6

Easy explanation: A /29 (255.255.255.248), regardless of the class of address, has only 3 host bits. Six hosts are the maximum number of hosts on this LAN, INCLUDING the router INTERFACE. Out of the 8 addresses POSSIBLE with the host bits, the first and the last address are for the subnet id and broadcast address respectively.

Correct option is (a) 172.16.112.0

For explanation I would SAY: A /25 mask is 255.255.255.128. Used with a Class B NETWORK, the third and fourth octets are used for subnetting with a total of 9 subnet BITS, 8 bits in the third OCTET and 1 bit in the fourth octet. Since there is only 1 bit in the fourth octet, the bit is either off or on-which is a value of 0 or 128. The host in the question is in the 0 subnet, which has a broadcast address of 127 since 128 is the next subne

Correct answer is (d) 5

The explanation is: A 240 MASK is 4 subnet bits and provides 16 subnets, each with 14 hosts. We need more subnets, so LET’s add subnet bits. One more subnet bit would be a 248 mask. This provides 5 subnet bits (32 subnets) with 3 HOST bits (6 hosts per subnet). This is the best answer.

Correct choice is (b) 255.255.255.224

For explanation I WOULD say: You NEED 5 subnets, each with at least 16 hosts. The mask 255.255.255.240 PROVIDES 16 subnets with 14 hosts which is less than 15, so this will not work. The mask 255.255.255.224 provides 8 subnets, each with 30 hosts so this may work. The mask 255.255.255.192 provides 4 subnets, each with 60 hosts so this may work. Comparing both the possible masks, 255.255.255.224 provides the best answer.

Right answer is (d) 30

To explain I WOULD say: A /27 (255.255.255.224) is 3 BITS on and 5 bits off. This provides 8 subnets, each with 30 hosts. Does it matter if this MASK is used with a Class A, B, or C network address? Not at all. The number of host bits would NEVER change.

Correct choice is (a) S/NET

Easy explanation: A 50-MBd active star fiber optical Local area NETWORK (LAN) and its optical combiner and mixing ROD splitter are presented. The limited power budget and relatively LARGE tapping losses of light wave technology, which limit the USE of fiber optics in tapped BUS LAN topologies, are examined and proven tolerable in optical star topologies.

The correct answer is (b) Fast ETHERNET

The explanation is: Fast Ethernet is a set of Ethernet STANDARDS which were INTRODUCED in 1995, that carry traffic at the nominal rate of 1000 Mbit/s. 100BASE-TX is the most COMMONLY used Fast Ethernet standard.

The correct choice is (d) All of the mentioned

To elaborate: In computer networking, Gigabit Ethernet (GbE or 1 GigE) is a term describing various technologies for transmitting Ethernet FRAMES at a rate of a gigabit per SECOND (1,000,000,000 bits per second), as defined by the IEEE 802.3-2008 STANDARD. It came into use beginning in 1999, gradually supplanting Fast Ethernet in wired local networks, as a RESULT of being considerably faster.

Correct answer is (a) FDDI

Explanation: FDDI stands for Fiber DISTRIBUTED Data INTERFACE. It is a set of standards for fiber OPTIC token ring LANs RUNNING at 100 Mbps over distances up to 200 km in diameter and 1000 stations connected.

The correct choice is (a) TRUE, True

Best explanation: In a CONNECTION oriented protocol, the host can only establish connection with another host on one unique CHANNEL, that’s why it can only use unicast addresses. In IPv6, there is an anycast address in IPv6 which ALLOWS sending messages to a group of devices but not all devices in a network.

Right answer is (a) STATIC SUBNETTING

To elaborate: Static subnetting is used when the REQUIREMENT is of same NUMBER of hosts in each subnet for the institution. The same subnet mask can be used to find the subnet id of each subnet. It is usually used to divide large networks into smaller parts.

The correct option is (c) SUBNET NUMBER and host number

The best explanation: It is termed as the local address because the address won’t be applicable outside the subnet. Sub networking is implemented for remote sensing in transparent WAY from that host which is contained in the sub NETWORK which called a local operation.

The CORRECT CHOICE is (c) 255.255.255.240

To explain I would say: If you have eight networks and each requires 10 HOSTS, you would use the Class C mask of 255.255.255.240. Why? Because 240 in binary is 11110000, which means you have four subnet BITS and four HOST bits. Using our math, we’d get the following:

24-2=14 subnets

24-2=14 hosts.

Right choice is (b) Class B, Subnet 172.16.13.0, BROADCAST address 172.16.13.127

Explanation: We know that the prefix 172 lies in class B (128 to 191) of IPv4 addresses. From the subnet mask, we get that the class is divided into 2 subnets: 172.16.13.0 to 172.16.13.127 and 172.16.13.128 to 172.16.13.255. The IP 172.16.13.5 lies in the first subnet. So the starting address 172.16.13.0 is the subnet address and LAST address 172.16.13.127 is the broadcast address.

Right option is (c) 172.16.255.255

The explanation: In this CASE, the class B network ID is 172.16.0.0. We KNOW that the default mask of a class B network is 255.255.0.0. If we OR any address in a network with the complement of the default mask (0.0.255.255), we get the broadcast address of the network. In this case, the result of OR WOULD be 172.16.255.255.

Right option is (a) Broadcast

To explain: There is no concept of broadcast ADDRESS in IPV6. Instead, there is an ANYCAST address in IPv6 which allows sending messages to a group of devices but not all devices in a network. Anycast address is not standardized in IPv4.

Right answer is (c) TOS field

Best explanation: The TRAFFIC class field is USED to specify the priority of the IP packet which is a similar functionality to the TYPE of Service field in the IPv4 header. It’s an 8-bit field and its values are not defined in the RFC 2460.

The correct OPTION is (d) 40bytes

Best explanation: IPV6 datagram has fixed header length of 40bytes, which results in faster processing of the datagram. There is one fixed header and optional headers which MAY or may not exist. The fixed header CONTAINS the mandatory essential information about the PACKET while the optional headers contain the optional “not that necessary” information.

Correct choice is (b) 128bits

The best I can explain: An IPv6 address is 128 bits long. Therefore, 2^128 i.e. 340 undecillion UNIQUE addresses are available in IPv6. IPV4 has only 4 billion possible addresses and IPv6 WOULD be a brilliant alternative in CASE IPv4 runs out of possible NEW addresses.

Correct ANSWER is (a) offset

To explain: The FRAGMENT Offset field specifies where the fragment fits in the original DATAGRAM. The offset of the first fragment will ALWAYS be 0. The SIZE of the field (13 bits) is 3-bits shorter than the size of the total length field (16 bits).

Right choice is (b) UDP

Explanation: The protocol FIELD ENABLES the demultiplexing feature so that the IP protocol can be used to carry PAYLOADS of more than one protocol type. Its most used values are 17 and 6 for UDP and TCP respectively. ICMP and IGMP are network LAYER protocols.

The CORRECT option is (c) 10

Explanation: TTL stands for TIME to Live. This field SPECIFIES the life of the IP packet based on the number of HOPS it makes (Number of routers it GOES through). TTL field is decremented by one each time the datagram is processed by a router. When the value is 0, the packet is automatically destroyed.

Right option is (c) TOS

For EXPLANATION: TOS-type of service identifies the type of PACKETS. It is not related to FRAGMENTATION but is used to request specific treatment such as high throughput, high reliability or LOW latency for the IP packet depending upon the type of service it belongs to.

Correct answer is (a) Error REPORTING

For explanation I would say: The Internet PROTOCOL is the networking protocol that establishes the internet by RELAYING datagram across network BOUNDARIES. ICMP is a supporting protocol for IP which handles the Error Reporting functionality.

The correct answer is (d) The IPv6 flow label is considered

For explanation: In the header translation procedure, first the IPv6 mapped address is changed to an IPV4 address by extracting the rightmost 32BITS, then the VALUE of the IPv6 priority FIELD is discarded, and finally the ToS field in the IPv4 header is set to zero. IPv6 flow label is ignored in the procedure.

The correct choice is (c) Mapped address

Easiest EXPLANATION: A mapped IPv6 address contains the IPv4 address in its LAST 32-bits and is preceded by 16 1S and 80 0S. It can be used to translate an IPv6 address to an IPv4 address.

Correct answer is (B) HEADER TRANSLATION

The EXPLANATION: Header translation is used when the SENDER wants to use IPv6, but the receiver does not understand IPv6. It is made possible through a Network Address Translation – Protocol Translation enabled device such as a gateway.

Correct choice is (d) TUNNELING

Explanation: In tunneling, The IPv4 ROUTERS can FORM a tunnel in which at the SENDER’s side, the IPv6 datagram is encapsulated in to IPv4, and at the RECEIVER’s side of the tunnel, the IPv4 packet is stripped and the IPv6 packet is sent to the receiver.

The correct answer is (b) Domain Name Server

Easy explanation: Source HOST queries DNS to DETERMINE which version to USE when sending a packet to a destination. The DNS contains both, the IPv4 and IPv6 addresses of the modern dual stack host SERVERS.

Correct option is (C) Conversion

For EXPLANATION: As IPv4 addresses are of 32 bits and IPv6 addresses are of 128 bits, it is not possible to convert IPv4 address to IPv6 address. So, Dual stack, tunneling and header translation are the three strategies which might help in the TRANSITION from IPv4 to IPv6.

Right option is (a) Huge number of SYSTEMS on the internet

The best explanation: Due to huge number of systems on the internet and the lower number of available addresses on IPv4, TRANSITION from IPv4 to IPv6 needs to happen. IPv4 provides around 4 billion unique IP addresses whereas IPv6 provides over 340 undecillion unique IP addresses.

Right OPTION is (a) 10101111 10100011

The explanation is: The sender side adds the bits of the fragmented packet to FIND a sum. CHECKSUM is the compliment of the sum (exchange 0’s and 1’s). The receiver then has to verify the checksum by adding the bits of the received packet to ensure that the packet is error-free.

Right option is (b) tracert

Best explanation: Tracert is USED in case of windows, whereas Traceroute in UNIX. Tracert is a program used to FIND the shortest route to the destination IP. The ROUTER sends destination unreachable MESSAGE if a path to the destination IP is not found.

Correct option is (c) ping

To explain I WOULD SAY: Ping program is USED to find if a host is alive and responding. It is to be entered into a command LINE with the syntax “ping (IP address)” to be executed. Traceroute is a program used to find the shortest ROUTE to the destination IP.

Right OPTION is (b) Round-trip time

The best I can explain: The round-trip time refers to the total time TAKEN combining the time taken for a packet sent from a source to reach a destination and the time taken the acknowledgement sent by the destination to reach the source. The Router sends destination unreachable MESSAGE if the destination is not found.

Right answer is (d) DECREMENTED by 1

To elaborate: This field will be decremented by 1 at EVERY router, and will be zero by the time it reaches source. This error reporting message is TYPE 11 and is USED to prevent the router from travelling forever in CASE some unknown path anomaly occurs.

Right OPTION is (b) flow control

To explain I would SAY: Firstly, it informs the source that the datagram has been discarded. Secondly, it WARNS the source that there is congestion in the network. It’s type 4 error reporting message after which the source is expected to REDUCE the flow of packets.

Correct option is (a) Destination UNREACHABLE

Easiest explanation: Router sends destination unreachable message if the destination is not found. Destination unreachable is type 3 error reporting message. It is INVOKED when the router can’t FIND a path to the intended destination to FORWARD the PACKET through.

Right option is (c) Router error

To explain I would say: Router error is not a type of error-reporting message in ICMP. The type of error reporting message is specified in the ICMP header. Destination UNREACHABLE is type 3 error message, source quench is type 4, and TIME exceeded is type 11 error message.

The correct answer is (b) Source

Easiest explanation: ICMP NOTIFIES the source about the ERROR when an error is detected because the datagram KNOWS information about source and destination IP address. The source can then RETRANSMIT the data again or TRY to correct those errors.

Right option is (a) 8-bytes

To explain I WOULD say: An ICMP message has an 8-byte header and a variable size data section. Out of the 8 bytes, the first 4 bytes are of a fixed format having the TYPE, code and checksum FIELDS and the next 4 bytes depend upon the type of the message.

The CORRECT option is (d) All of the mentioned

For explanation: IP by itself does not provide the FEATURES of ERROR reporting or error correction. So, to address these issues a network layer protocol called Internet Control Message Protocol is used. ICMP operates over the IP PACKET to provide error reporting functionality.

The correct answer is (d) Demultiplexing

Easiest explanation: Demultiplexing is the process of error checking and dropping of the header, delivering messages to appropriate process BASED on port number. The transport layer does this on the receiver’s end after the PACKET is received and TAKES help of the header attached by the sender’s SIDE transport layer during multiplexing.

Right CHOICE is (c) Sender site

The best I can explain: At the sender’s side, there are multiple processes which may want to SEND packets. But there is only one transport layer protocol like TCP or UDP working at a TIME. So the transport layer protocol GETS the messages from these processes and separates them with different port numbers. This PROCESS is called multiplexing and it is done before sending packets to the receivers side.

Right choice is (b) Packets are not delayed

For explanation I would SAY: There is a high probability in connectionless services like UDP that the packet GETS delayed or lost because there is no connection made between the TWO END nodes. No connection means that there is no UNIQUE pathway for the packets to travel.

Right option is (a) Socket address

Best EXPLANATION: Socket address is the combination of an IP address and a PORT NUMBER and it is used to define the client-end and server-end PROCESSES uniquely.