Q1. Answer following in one or two sentences, (Any twenty)                            (20)

1.Why an IP Classful address specifies a connection to network rather then an individual computer?

2.What is the purpose of keeping a special IP address of value all zeroes?

3.Why there is a need for RARP?

4.ARP request is broadcasted but reply is not. Why?

5.What is the purpose of the PROTOCOL field in the IP datagram?

6.What is Differentiated Services?

7.Why reassembly timer is useful?

8.Why Time To Live does not actually count the time?

9.Why IP has adopted next-hop-routing?

10.What is the need for host-specific-routes?

11.Why a router can not determine all causes of error in delivery?

12.What is the need for router advertisement ICMP packet?

13.What is the need for keeping subnet addressing common for all the networks in the organization?

14.What is subnet mask?

15.Why anonymous networks do not require IP addresses?

16.What is the purpose of the field Window  in TCP header?

17.What is the reason for longest match routing required in CIDR?

18.What is the reason of using port numbers when we can use process id to identify processes?

19.What is the requirement of having passive and active open in TCP?

20.Why TCP is required to work with out of band data?

21.What do we mean by ambiguous ack?

22.Why variance in delay is considered while calculating timer value in TCP/

23.What is karn’s algorithm?

Q2. Answer any one.     (5)

1.Consider IPv4 and reply

a.In a datagram M bit is zero, the value of HLEN is 5, the value of TOTAL LENGTH is 200 and the offset value is 200 then, what is the first data byte of the datagram, what is the last data byte, and what is the number of this fragment? 1st, last or the middle?

b.An IP datagram must visit router 128.45.3.4. There is no restriction about other routers to be visited. What is the option that is to be used?

c.A datagram is carrying 1024 bytes of data. If there is no option information, what is the value of header length field? What is the value of Total Length field?

2.An ISP is granted a block of addresses starting with 150.80.0.0/16. The ISP wants to distribute these blocks to customers as follows. Show how subnetting can solve this problem.

a.The first group has 200 medium size businesses, each requires 128 addresses.

b.The second group has 400 small businesses, each requires 16 addresses.

c.The third group has 2048 households, each need 4 addresses.