April
1999 QUESTION 3 Total Marks: 20 Marks |
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| (a) | Explain why we have the redundancy of using
both domain name and IP addresses in the Internet.
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[3] |
| (b) | What is the DNS? Why does it have to be
distributed?
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[4] |
| (c) | Explain the term port address. Is it
the same as an IP address ? Use an example to explain your answer.
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[4] |
| (d) | Discuss at least two basic differences between
IP address and Ethernet address.
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[4] |
| (e) | Before IP packets can be sent, the destination
ethernet address must be determined, using the address resolution protocol (ARP). The
first phase of operation of the ARP is to look up the address in a locally-held table. What happens to the IP packets whose address lookup in the ARP table fails? How do the packets eventually get sent? |
[5] |