CS610 Final Term Solved Subjective with References by Moaaz

CS610- Computer Network · Solved Subjective · From Midterm Papers · June 23,2012 · PSMD01 · Fall 2012

Q: differentiate between IP and transport protocol with the help of example. (2 Marks)

Answer: (Page 119) 1-IP provides computer-to-computer communication while TP provide application-to-application communication. 2-IP source and destination addresses are computers while TP need extended addressing mechanisms to identify applications 3-IP is also called machine-to-machine communication while TP are called end-to-end communication.

Q: Give the main advantage and disadvantage of RIP. (2 Marks)

The biggest advantage of RIP is that it is simple to configure and deploy. The biggest disadvantage of RIP is its inability to scale to large or very large networks. The maximum hop count used by RIP routers is 15. Another disadvantage of RIP is its high recovery time.

Q: Tel the first assignable IP address from a 128.140.80.24/20. (2 Marks)

The host address range for this subnet is 128.140.80.1 - 128.140.95.254, so the first assignable IP address is

128. 140.80.1.

Q: how was the NAT implemented? (2 Marks)

Answer: (Page 130) We can see that the old and new values of IP source field and destination field are shown with their directions.

NAT device stores state information in table. The value is entered in the table when NAT box receives outgoing datagram from new. Q: IS ATM including LAN and WAN network. If yes what kind of connection is established? (2 Marks)

Answer: (Page 66) Yes it includes LAN and WAN network and established connection-oriented connection.

Q: is IP multicasting beneficial? Defend your answer with proper reason. (3 Marks)

We assume that IP multicast is more beneficial for the channels with a high popularity, and therefore these channels will be preferred when the number of available multicast groups is smaller than the number of channels.

Q: Can the length of the segment be increased 500 meter by adding three repeater one with each segment. It can be done or not. (3 Marks)

Answer: (Page 49)

Q: How an administrator can handle static and dynamic routing. (3 Marks)

Routing can be handled by a static routing table built by the system administrator. Static tables do not dynamically adjust to changing network conditions, so each change in the table is made manually by the network administrator.

Routing can be handled by a dynamic routing table that responds to changing network condition. Dynamic routing tables are built by routing protocols.

Q: IS TCP/IP suit including ARP. What kind of messages are in ARP. (3 Marks)

Answer: (Page 97) The TCP/IP protocol suite includes an Address Resolution Protocol (ARP). The ARP standard defines two basic message types:

• Request
• Response

Q: Traceroute continues to increment the Time To Live until the value is large enough for the datagram to reach its final destination. What happens when the TTL is sufficiently large for the datagram to reach its destination? (3 Marks)

To learn when a datagram reaches its destination, traceroute sets the UDP destination port number in the datagram to a very large value that the destination host is unlikely to be using. When a host receives a datagram destined to it containing a destination port number that is unused locally, it sends an ICMP port-unreachable error to the source.

Q: describe characteristics of BGP. (5 Marks)

Answer: (Page 138) It is most popular Exterior Gateway Protocol in Internet. It has following characteristics: " It provides routing among autonomous systems (EGP). " It provides policies to control routes advertised. " It uses reliable transport (TCP). " It gives path of autonomous systems for each destination. " Currently the EGP is of choice in the Internet. " The current version is four (BGP-4). " It provides facilities for Transit Routing.

Q: describe IPV6 addressing notation. (5 Marks)

Answer: (Page 114)

128-bit addresses unwisely in dotted decimal; requires 16 numbers:

105. 220.136.100.255.255.255.255.0.0.18.128.140.10.255.255

Groups of 16-bit numbers in hex separated by colons – colon hexadecimal (or colon hex). 69DC: 8864:FFFF: FFFF: 0:1280:8C0A:FFFF

FF0C: 0:0:0:0:0:0:B1 FF0C::B1

IPv6 address with 96 leading zeros is interpreted to hold an IPv4 address.

Q have there is a technique for achieving reliability through TCP. (5 Marks)

Answer: (Page 123) Reliability is the responsibility of the Transport layer. In TCP/IP, TCP provides reliable transport service. Most Internet applications use TCP as no other protocol has proved to work better.

SERVICE PROVIDED BY TCP:

Following are the services provided by TCP:

• Connection-oriented service
• Point-to-point
• Complete reliability
• Full-duplex communication
• Stream interface
• Reliable connection startup
• Graceful connection shutdown