CompTIA
A+ Certification
A+
Operating Systems (220-232) exam notes
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A+
Certification, awarded by CompTIAŽ organization is the most widely recognized
certification in the area of PC
hardware and software technologies. To attain A+ certification,
one need to pass 2
exams, namely, A+ Core Hardware Technologies, and A+ Operating
Systems Technologies. These exams basically
test the skills in assembling a computer, troubleshooting, and the ability to work with various
operating systems. Linux is not included in the A+
Certification Operating Systems exam, as it has an exam of its
own (Linux+ Certification), offered by CompTIA.
The exam cram offers several final preparation
points for candidates intending to appear for
the A+ test. Latest objectives are
available from Comptia.com website.
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21. If Autoexec.bat tried to access a drive letter that is
not valid, the error message "Current drive is no
longer valid" appears.
22. VIRUS:
1.
A boot sector virus stays resident by infecting the boot
sector of the computer
2.
A Master boot record (MBR) virus infect the first physical
sector of all affected disks
3.
File viruses either replace or attach themselves to
executable files, and most commonly found virus.
4.
Macro virus attaches itself to documents in the form of
macros.
5.
Memory viruses are viruses that execute and stay resident
in memory. Trojan Horse is an example of memory virus.
23. TCP/IP
-
TCP/IP is the protocol used when you are Telnetting to a
remote host. HTTP is
used for accessing the World Wide Web services.
-
SMTP is used to upload mail to the mail server. POP3 is
used for downloading mail from a mail server to a
client machine running POP3 client.
-
Both PPP and SLIP can be used for dial up connections.
However, SLIP can't be used where the IP address need
to be assigned dynamically. The advantage of PPP is
multi protocol support, that it can support TCP/IP,
IPX, AppleTalk etc. SLIP can support only TCP/IP and
IP addresses need to be assigned manually.
-
WINS server resolves the NetBIOS names to IP addresses. A
Windows network running TCP/IP need to be configured
with WINS (or LMHOSTS file on each computer)
for NetBIOS name resolution.
24. Networking utilities:
1.
NBTSTAT: This utility displays current NetBIOS over TCP/IP
connections, and display NetBIOS name cache.
2.
NETSTAT: Displays protocol statistics and current TCP/IP
connections since the server was last booted.
3.
TRACERT: Used to determine which route a packet takes to
reach its destination from source.
4.
IPCONFIG: Used to display
Windows IP configuration information.
5.
NSLOOKUP: This utility enables users to interact with a DNS
server and display resource records.
6.
ROUTE: Used to display and edit static routing tables.
25. Some of the important commands useful in trouble
shooting TCP/IP networks are:
1.
Ipconfig: Displays TCP/IP configuration values, including
IP address, subnet mask, and default gateway.
2.
Ping: This command can be used to verify whether the
target ip address or host name is present. You need to
specify the target IP address or host name. You can
ping the loop back address at 127.0.0.1. A response ensures that the TCP/IP stack is installed properly
on your computer.
3.
Route: Displays
and manipulates route information.
4.
Tracert: Determines the route packets take to reach the
specified destination.
26. To see TCP/IP configuration on a Windows 95 / 98
computer, use WINIPCFG.
It will display your IP address, subnet mask, default
gateway, hardware MAC address.
To see TCP/IP configuration on an NT machine, use IPCONFIG.
It will also display the IP configuration information
on an NT machine. To get more details, use IPCONFIG/ALL.
27. DLL stands for Dynamic Link Library. DLL is a special
form of application code loaded into memory by
request. A DLL is not executable by itself.
More than one application may use the functions
offered by a DLL.
28. HTML stands for Hyper Text Markup Language. HTML is the
language most widely used for writing Web pages.
29. You can't apply file level permissions on a FAT file
system. Only NTFS allows file permissions. Remember
that the NTFS file permissions are always in effect to
all users and processes.
30. PAP and CHAP:
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PAP uses 2-way handshaking. Passwords are sent in clear
text across the link. Therefore, PAP is to be used
only when it not possible to use CHAP.
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CHAP uses 3-way handshaking. CHAP uses Challenge/ Response
method, that provides protection against the password
capture while authenticating the user. One should use
CHAP whenever it is possible.
