Networking
1. What's the definition of a router?
Ans:
a device that direct the traffic by forwarding data being transmitted towards its destination
2. What's the definition of a gateway?
Ans:
a collection of hardware and software that acts as an entrance to another network
3. Is a server a hardware or software?
Ans:
Software
4. What are the filename extensions of HTML files?
Ans:
.html (W3C's standard), .htm (Microsoft's standard for its 8.3 file naming convention)
5. What's the long form of HTML?
Ans:
Hypertext Markup Language
6. Which program fulfills requests for files from web browsers?
Ans:
Web server
7. Evaluate the decimal number 817. Illustrate your steps.
Ans:
8*10^2 + 1*10^1 + 7*10^0
=800 + 10 + 7
=817
8. Evaulate the following binary number and express their values in decimal form.
Ans:
0*2^2+0*2^1+1*2^0
=1
Ans:
1*2^2+0*2^1+1*2^0
=5
Ans:
1*2^2+1*2^1+0*2^0
=4+2+0
=6
9. The original permission setting of a file, file1, is rw-------. Give 3 possible options of chmod to change the permission setting to r-x-w---x.
Ans:
chmod u-w+x, g+w, o+x file1
chmod u=rx, g=w, o=x file1
chmod 521 file1
10.The original permission setting of a file, file1, is rw-------. Show the new permission setting if the following command line is executed.
chmod 654 file1
rw-r-x-r--
11. To post a directory onto the Internet, why the execute permission must be granted to other?
And:
to allow others to use that directory as the present working directory (pwd)
12. Render the following web page.
<html>
<head>
<title>My table</title>
</head>
<body>
<table width="50%" border="1" cellspacing="2" cellpadding="2">
<tr>
<td>1</td>
<td>2</td>
<td>3</td>
<td>4</td>
</tr>
<tr>
<td>F</td>
<td>H</td>
<td>E</td>
<td>G</td>
</tr>
<tr>
<td>B</td>
<td>D</td>
<td>A</td>
<td>C</td>
</tr>
</table>
</body>
</html>
Ans:
13. If there are 65537 computers on a network, in order to connect this network onto the Internet. Which class of IP address should be assigned to these computers.
Ans:
| Class | # of networks can be identified | # of hosts in each network |
|---|---|---|
A |
126 |
16 million |
B |
16382 |
64K |
C |
2097152 |
254 |
Class A
14. Which class of IP address does this IP address belong to? Also, convert this IP address into dotted decimal form.
| 1 | 0 | 0 | 1 | 1 | 1 | 0 | 0 | 0 | 1 | 0 | 1 | 0 | 1 | 0 | 0 | 0 | 1 | 1 | 0 | 1 | 0 | 1 | 1 | 0 | 0 | 1 | 0 | 1 | 0 | 1 | 1 |
Ans:
| Class | 1 | 5 | 10 | 15 | 20 | 25 | 30 | |||||||||||||||||||||||||||
| A | 0 | Network (7 bits) |
Host (24 bits) |
|||||||||||||||||||||||||||||||
| B | 1 | 0 | Network (14 bits) |
Host (16 bits) |
||||||||||||||||||||||||||||||
| C | 1 | 1 | 0 | Network (21 bits) |
Host (8 bits) |
|||||||||||||||||||||||||||||
| D | 1 | 1 | 1 | 0 | Multicast address |
|||||||||||||||||||||||||||||
| E | 1 | 1 | 1 | 1 | 0 | Reserved for future use |
||||||||||||||||||||||||||||
This is a Class B IP address.
| 1 | 0 | 0 | 1 | 1 | 1 | 0 | 0 | 0 | 1 | 0 | 1 | 0 | 1 | 0 | 0 | 0 | 1 | 1 | 0 | 1 | 0 | 1 | 1 | 0 | 0 | 1 | 0 | 1 | 0 | 1 | 1 |
| 1*2^7+0*2^6+0*2^5+1*2^4+1*2^3+1*2^2+0*2^1+0*2^0 | 0*2^7+1*2^6+0*2^5+1*2^4+0*2^3+1*2^2+0*2^1+0*2^0 | 0*2^7+1*2^6+1*2^5+0*2^4+1*2^3+0*2^2+1*2^1+1*2^0 | 0*2^7+0*2^6+1*2^5+0*2^4+1*2^3+0*2^2+1*2^1+1*2^0 | ||||||||||||||||||||||||||||
156 |
84 |
107 |
43 |
||||||||||||||||||||||||||||
156.84.107.43 |
|||||||||||||||||||||||||||||||
15. Give the command line to resolve the IP address of the domain mcs.csuhayward.edu.
Ans:
nslookup mcs.csuhayward.edu
Security
1. Provide the following 4 types of security threats
a) Passive attack can cause which security threats
Ans:
unauthorized access, unauthorized disclosure of information
b) Active attack can cause which security threats
Ans:
unauthorized access, unauthorized disclosure of information, unauthorized modification of information, unauthorized denial of service
2. Using monoalphabetic cipher and the sample key in the lecture note. Encrypt your last name.
Privacy, Ethical and societal issues
1. Under patent protection, how long can a patent holder have the exclusive rights on the invention?
Ans:
20 years