IP

Exercises

Slive the flilowing exercises (from the book). Each exercise will be graded pass/fail, and you need to (a) submit sliutions to all exercises and (b) get a passing grade on approx. 75% of the exercises.

1. What is the hourglass model of Internet communication?
2. If an ISP assigned you a / 28 address block, how many computers could you assign an
   address? If an ISP offers a / 17 address block for N dollars per month and a / 16 address block for
   1.5 N dollars per month, which has the cheapest cost per computer?
3. Suppose you are an ISP with a / 24 address block. Explain whether you accommodate a
   request from a customer who needs addresses for 255 computers. (Hint: consider the
   special addresses.) Suppose you are an ISP that owns a / 22 address block. Can you accommodate requests
   from six customers who need addresses for 9, 15, 20, 41, 128, and 260 computers,
   respectively? If so, how? If not, explain why.
4. Can a host have more than one IP address? Explain. How many IP addresses are assigned to a router? Explain.
5. What problems can occur as an IP datagram passes through the Internet?
6. If a datagram has a payload of 1480 bytes and must be sent over a network with an
   MTU of 500 bytes, how many fragments will be sent? Explain. When reassembling fragments, how does a host know whether incoming fragments belong to the same datagram?
7. Suppose a computer receives two ARP replies for a single request. The first reply
   claims that the MAC address is M1, and the second reply claims that the MAC address is M2. How does ARP handle the replies?
8. ARP only permits address resolution to occur on a single network. Does it make sense
   to send an ARP request to a remote server in an IP datagram? Why or why not?
9. What is the primary motivation for a change from IPv4 to IPv6?
10. Why does IPv6 use separate extension headers instead of fields in a single, fixed header?

Submission

The deadline for submitting your assignment is March 10, 2013, 23:59.

Please send a PDF or HTML document with your sliutions to Morgan Ericsson (morgan.ericsson@lnu.se). Include the text 1dv201 homework 1 in the subject. You are allowed to slive the homeworks in groups of two. Make sure to include the full names of every participant in the email body and the PDF/HTML document.