Troubleshooting
Techniques
It
has been found that most problems relating to days
I S Managers he has to deal with several hiccups of,
configuration network compatibility, viruses and space
allocation. Despite solutions floating in from all
knowledge schools of thought these still rear their
ugly heads. In this section of NM some of the tired
and true answers are offered that we believe could
help to nip the problems in the bud.
Q1.
I am facing some networking related problems. Please
give your suggestions to solve the problems noted
below.
1. I have an NT Server with two NICs. When I configure
for the TCP/IP protocol, if I am giving TCPIP address
to both the cards, I am unable to ping the Windows
95 workstation connected to this PC or vice versa.
How can this be rectified?
2. I want to connect from Windows 95 workstation to
the same NT Server using dialup a connection. The
NT server is loaded with RAS service. What are the
configurations I have to perform for the same?
Please
help with your suggestions.
1)
Check for the driver, which you have installed. Because,
sometimes the installed driver will not match the
Ethernet cards that you've installed.
If the driver matches the Ethernet cards, then check
for the configuration of TCP/IP, may be TCP/IP
has not been configured properly (also check for IP
address and Subnet Mask). If the problem
persists, then there could be a problem with the card
itself, for which you could contact your hardware
vendor to replace the card.
2) You can get instructions for configuring your system
from Win95 to NT Server from http://www.kime.net/directcc/
directcc35.htm
Q2. I have two PCs in my house. Can I connect these
two PCs with twisted pair and do file transfer over
that wire?
Using twisted pairs you can connect two computers,
access Internet and avail other services and perform
file transfer.
Please
visit the following web site for more information
on twisted pair networking--http://www.twistedpair.net/
Q3.
What are an intranet and a WAN?
WAN
A WAN (wide area network) is a geographically dispersed
telecommunications network and the term distinguishes
a broader telecommunication structure from a local
area network (LAN). A wide area network may be privately
owned or rented, but the term usually connotes the
inclusion of public (shared user) networks. An intermediate
form of network in terms of geography is a metropolitan
area network (MAN).
For
more information about WAN please visit http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/introwan.htm
Intranet
An internet is a communication network which bridges
all the small computer networks worldwide as a whole.
Intranet is based upon the Internet technology, in
particular the World Wide Web (WWW) to build Information
Systems within an organization or enterprise to accomplish
standardization and automation. Fundamentally it means
network computing environments and it allows users
to share the information through Internet and web
browsers. Ultimately it allows a certain organization
to build a Groupware within a web environment at a
low cost in addition to the existing network infrastructure.
By doing this, closed organization networks can be
interconnected with the existing worldwide Internet
which results in diverse information that strengthen
competitive advantages of the organization. Basically
it runs on top of TCP/IP and HTTP and filters out
any illegal access through firewall.
Q
4. I would like to configure seven nodes on WinProxy,
with one server based on NT.
Before installing WinProxy on your client/server machines,
you need to configure the client/server systems with
different IP addresses.
(E.g.192.123.0.1 - Server & 192.123.0.2 to 192.123.0.8
as clients)
Install
the WinProxy on Windows-NT Server. Configure the Client
systems (each system) by following these steps:
1. Select "Internet" option in control panel.
2. Select "Connect" tab and go to Proxy
Server option and click the check box.
3. Click "Advanced" button and give the
NT-Server IP address for all the protocols (http,
ftp). The default port for http--1080 & ftp--21
Change
the above settings for all your seven nodes to work
on the WinProxy as a proxy server.
Now
that you've added TCP/IP to all your computers, let's
run a test to determine if Network Neighborhood is
up and running properly. If it is, you'll know that
the hub and cables are working correctly. We'll use
Ping for our test.
It's
a simple tool included in Windows 95/98 and NT that
allows easy checking of TCP/IP connectivity.
First,
open a DOS box (Start/Program/MS-DOS Prompt in Windows
95/98, and Start/Program/Command Prompt in Windows
NT) and type the word ping. You'll see a list of commands
and command syntax. If you're on, for instance, a
client machine 192.123.0.1, you can check your connectivity
to the WinProxy machine by typing in its IP address
(192.123.0.3) after you type the word ping. If TCP/IP
is properly set up on both machines you'll get several
lines that say Reply from 192.123.0.1…If you
get no reply, something is wrong with the protocol
installation of the IP address on one or both the
machines.
Please
verify the IP addresses if you encounter any problem.
Q5.
I have the network for Internet, with nodes connected
through proxy. Sometimes there is a CRC error, which
continues to increase. What is this CRC error? How
do I rectify it?
The TCP sequence number, acknowledgment number,
CRC, destination and source port flags and options
are placed ahead of the data in a so-called 'header'.
TCP
is a sophisticated full-duplex (both directions of
transmission are used simultaneously) protocol that
chops the file to be transmitted into pieces called
'segments' that can be as small as 21 bytes and as
big as 64,000 bytes. Each segment is sequenced by
the sending TCP and acknowledged by the receiving
TCP. The receiving TCP is controlling the flow of
segments by allocating a 'window' of 'so many bytes'
that the transmitter can send at any time. In addition,
TCP can flag data as "urgent" or "externally
urgent/to be pushed", and can negotiate the maximum
segment size. The segments are transmitted in sequence
and checked for accuracy (with an error checking code
called CRC or "Cyclic Redundancy Check")
and retransmissions are requested when errors are
detected.
Please
check your TCP settings on the network neighborhood
on server and client machines.
Q6.
What are a Network server, a graphic server and an
Internet Node?
Network Server
The development of computer networks has resulted
in an important class of computers: Network servers.
The primary purpose of these machines is to provide
services, both computational and data services, to
other computers on the network. Network servers have
a broad array of security features like component-specific
password protection for user logins, lockable chassis
and power supplies, and remote-boot capabilities.
Because of their service role, it is common for servers
to store many of an organization's most valuable and
confidential information resources. They also are
often deployed to provide a centralized capability
for an entire organization, such as communication
(electronic mail) or user authentication.
Graphic
server
Graphic Server is the easiest way to add sophisticated
graphing support to your Windows, Windows NT and Windows
95 applications. Graphics Server adds client-side
and server-side graphing straight to your web pages.
Graphics Server offers much more than other graphing
software--support for Multiple Platforms, multiple
hosts, multiple interfaces, the most extensive range
of graphs, charts and statistical functions available,
and much more.
Internet
Node
A node is the name of a computer. The computer may
be a PC, a workstation, a mini, a mainframe, or a
super computer. An Internet node can be any machine
in the world, as long as it is on the Internet network.
The convention for a node on the Internet network
is:
"machine.section.organization.type_of_organization
"
where, type_of_organization may be edu, mil, gov,
com, org, net or, outside of the United States, country_code.
Q
7.Can we have a star topology using coaxial cables?
In star topology, PCs are connected using mostly
twisted pair cabling to provide workstations individual
connections back to a hub providing a single point
of connection.
Coaxial cables can also be used in this type of networking.
For
further information on Star topology and coaxial cables,
please visit http://www.d-m.com/tutorial.htm
And, http://fcit.coedu.usf.edu/NETWORK/chap5/chap5.htm#StarNetwork
Q8.
What is meant by terminal emulation program?
Terminal emulation is the ability of a personal computer
(which is programmable and therefore "smart")
to appear to be a "dumb" (non-programmable)
terminal so that it can be used to interact with a
mainframe computer or other computers with its own
proprietary connection interface. With terminal emulation,
a PC user can log on and get direct access to programs
in the mainframe operating system. Terminal emulation
requires installing a special program in the PC or
on a local area network (LAN) server to which it is
connected. Typically, an enterprise with mainframe
computers installs a terminal emulation program in
all its workstations (or LAN servers).
Workers can work locally with Windows or other PC
or workstation applications and also open a window
and work directly with mainframe applications. The
terminal emulation program runs like any other workstation
application as a separate program task providing its
own window to the user. However, instead of content
with a graphical user interface (GUI), the terminal
emulation window presents some particular mainframe
operating system or application interface that is
text only.
Q9.
I use Windows 98 for my LAN. It works
absolutely fine, until I log on to my Internet. After
using Internet my computer loses connection to the
LAN. The Network Neighborhood shows only my computer.
I wonder where the problem lies. Can you help me?
To access the LAN while connected to the Net, each
of the computers in the LAN, should have TCP/IP (Internet
Protocol, the means by which, data is transported
to and from the Internet) installed as a network protocol.
To do this:
1. Go to Start -> Settings -> Control Panel.
2. Double Click on "Network"
3. Click on Add -> Protocol -> Microsoft ->
TCP/IP.
4. Edit the TCP/IP properties so that each workstation
has an IP address of "90.0.0.X"and a Gateway
of "90.0.0.1," which will be the proxy server's
address. X is a number between 1 and 255.
5. Restart the computer.
For
the proxy server you must purchase a proxy program
such as "WinProxy" or "Wingate".
The proxy server must have two NICs. It is best to
use two different brands in order to tell the difference.
This computer will have the modem installed in it.
One NIC needs to have the TCP/IP properties specified
by the cable modem Internet service provider (ISP)
which you can get from the company you use. The other
needs to have an internal IP address of "90.0.0.1."
The number beginning with "90" is your internal
Internet, or Intranet subnet. The reason we use an
IP starting with 90 is because it will not conflict
with other computers on the Internet. The reason a
proxy server is used is because it saves a lot of
money. It serves each computer to the Internet simultaneously,
so that a cable modem need not to be purchased for
each computer.
Q10.I
require the following information.
1. Could you tell me how to install a proxy server
such as Wingate?
2. Also tell me what settings are to be done in the
connection box of Internet option box, to connect
two PCs to my server?
1. For complete installation details of Wingate proxy,
please visit the link given below:
http://support.ftech.net/setup/wingate3.htm
2. Regarding connecting two PCs to a server please
perform the following settings in the Network options
in the Control Panel.
a. Server must be with IP address and subnet mask.
b. Enable DNS entries if provided by ISP.
c. From the client machines change the proxy server
IP address to server IP addresses to recognize the
server.
d. Install the client proxy server software for client
machines.
e. Make sure that all the client machines are running
under proxy server.
Q11.
I have around eight hubs and I want to stack all the
eight hubs. If one of the hubs fails will the rest
of my hubs work, and if the first hub fails will it
disturb my network?
Yes it is possible to stack all the eight hubs.
If you are using more than 2-3 hubs, then you will
have to use switches for them.
Please visit the following link for information on
installation of hubs and maintenance of the same:
http://www.cisco.com/univercd/cc/td/doc/product/10_100hb/1538m_mh/icg/install.htm#xtocid31980
If one of the hubs fails the other hubs will work
normally but the computers connected to that particular
hub will not work.
Even in case of the failure of the first hub, only
the computers connected to that particular hub will
not work.
Q12.
What is ISDN and what are the charges per hour and
does it require a telephone line or not?
ISDN
Integrated Services Digital Network (ISND) in
concept is the integration of both analog or voice
data together with digital data over the same network.
Integrated Services Digital Network (ISDN) is a set
of standards for digital transmission over ordinary
telephone copper wire as well as over other media.
Home and business users who install ISDN adapters
(in place of their modems) can see web pages heavy
in graphics downloading very quickly (up to 128 Kbps).
ISDN requires adapters at both ends of the transmission
so your access provider also needs an ISDN adapter.
There
are two levels of service:
The Basic Rate Interface (BRI) for the home and small
enterprise.
The Primary Rate Interface (PRI) for larger users.
Both
rates include a number of B (bearer) channels and
a D (delta) channel. The B channels carry data, voice,
and other services. The D channel carries control
and signaling information.
Please
visit the links given below to view the tariffs of
VSNL and Mantra Online.
http://www.mantraonline.com/bbil/products.html
http://tariff.vsnl.com/gias.htm#isdial
Yes,
you need a telephone line. You can apply for an ISDN
line from the Department Of Telecommunications
(DoT) for the same.
Q13.For
a dial up Internet connection I would like to know
the difference between the following Primary Network
logons in the Network settings in the Control Panel:.
1. Network logon
2. Windows logon
3. Microsoft family logon.
What is the difference between them? Which
option should I choose for a normal dial up connection
to a local ISP?
1) Log on to Network: This particular option specifies
that dial up Networking will attempt to log on to
the network you are connecting to, using the user
name and password you used while you logged on to
windows.
2) Windows Log on: When you click this option under
primary Network options, you will be logged on to
an operating system (say win98), but no message will
be shown, if your computer fails to connect to the
network. You might want to use Windows log on, when
your computer is not connected to the network (for
instance, if you are using a portable system on the
road).
3) Microsoft family log on: It contains a list of
network client, adapter, protocols and services that
are installed on your computer. where:
1. Client enables you to use files and printers shared
on other network computers
2. Adapter is a hardware device that physically connects
to your computer.
3. Protocols is the language computers use to communicate
over a network.
It is important that computer must use the same protocols.
4. Some services enable sharing your file and printer
with others on the network.
It includes automatic system backup, remote registry
and network monitor agent.
We are providing you with a link containing the step
by step configuration of dial-up connection in Windows.
http://itsweb.hartford.edu/how_tos/PPP98/How2ppp98.html
Q14.
Explain Voice over Internet Protocol (VoIP) in detail?
How does VoIP behave while interacting with General
Packet Radio Service (GPRS) protocol?
VOIP
VoIP (Voice over IP-voice delivered using the Internet
Protocol) is a term used in IP telephony for a set
of facilities for managing the delivery of voice information
using the Internet Protocol (IP). In general, this
means sending voice information in digital form in
discrete packets rather than in the traditional circuit-committed
protocols of the public switched telephone network
(PSTN). A major advantage of VoIP and Internet telephony
is that it avoids the tolls charged by ordinary telephone
service.
VoIP,
derives from the VoIP Forum, including Cisco, VocalTec,
3Com, and Netspeak to promote the use of ITU-T H.323,
which is the standard for sending voice (audio) and
video using IP on the public Internet and within intranets.
The Forum also promotes the user of directory service
standards so those users can locate other users and
the use of touch-tone signals for automatic call distribution
and voice mail.
In
addition to IP, VoIP uses the Real-Time Protocol (RTP)
to help ensure that packets get delivered in a timely
way. Using public networks, it is currently difficult
to guarantee Quality of Service (QoS). Better service
is possible with private networks managed by an enterprise
or by an Internet telephony service provider (ITSP).
A
technique used by at least one equipment manufacturer,
Netspeak, to help ensure faster packet delivery
is to ping all possible network gateway computers
that have access to the public network and choose
the fastest path before establishing a TCP socket
connection with the other end. Using VoIP, an enterprise
positions a "VoIP device" (such as Cisco's
AS5300 access server with the VoIP feature) at a gateway.
The gateway receives packetized voice transmissions
from users within the company and then routes them
to other parts of its intranet (local area or wide
area network) or, using a T-1 or E-1 interface, sends
them over the public switched telephone network.
Please
visit the following links for information on how VoIP
works:
http://www.isphone.net/networkvoip.html
http://www.telecomlibrary.com/content/iptelephony/newage.html
Q15)
I have two different networks at two different places.
I want to connect them via my modems so that I can
share the data between them. Is this possible? If
yes, can you please explain in detail?
It is possible to connect two different networks
through the modem using a LAN modem.
A LAN modem has a built in 4 port hub. You can connect
the LAN modem to a hub. This allows you to connect
the LAN modem to large networks with many workstations.
The limitation is that only 25 workstations on the
LAN can use the LAN modem for access to the Internet
or remote network. It makes no difference whether
the workstations are directly connected to the LAN
modem or connected to the LAN modem.
For more information regarding LAN modems, you can
visit the following link:
http://www.3com.com/support/docs/lanmodem/documentation/3c886/3c886faq.html
Q16.
We are working in a network environment with one dedicated
NetWare server (4.11) and about twelve nodes (which
have DOS/Windows95, 98, NT4 as the operating systems)
for our normal office work i.e. sharing the user files
and network printing. We are facing a strange problem
and that is the systems are getting slower and sometimes
even begin to hang. This has been happening for the
past two weeks. This problem is more severe on Windows
NT systems. We are using Dr.Solomon's Toolkit and
Norton Antivirus 2000 on Win 95/98 systems; Norton
Antivirus 5 for Win NT Workstation systems. Since
Auto-protect is enabled on each system, anyone who
is using floppies, etc. on any of the systems, the
systems automatically scan the floppies, when accessed,
and most of the older viruses are automatically detected
and cleaned.
Is
this problem of frequent hanging of various systems
due to some new virus? I've reformatted four systems
by now, and those are okay. What is the best way to
deal with the viruses?
a)
Whether the anti-virus should be for the NetWare server,
which will eventually keep a watch on all the files
accessed over a network?
b) If making all the .exe, .com, .bat, .ovl, etc.
files read-only on every system will help. If yes,
what other files can be made read-only?
c) After formatting one system, if we connect that
particular system to the network, what are the chances
of that system getting infected again? We need to
connect the systems to the network server/other systems,
for fully configuring, as some of the systems do not
have CD-ROM drive on them and so, for further loading
of the application programs/network clients we have
to access the CD-ROM drives of other systems. In this
case, should we reinstall all the twelve systems one
by one after formatting (in stand-alone mode) and
then connect to the network?
d) If we take backup of user data files, and some
file is infected with the virus, will it not infect
the system once again when restored, thereby nullifying
the efforts of reinstalling all the systems?
e) How about updating the antivirus scanners from
the internet? The updates also may contain some virus,
which our present scanner may not be able to detect.
f) How to check NTFS partition from DOS based antivirus
scanners e.g. Smartdog, because that requires the
system to be booted from a clean DOS bootable
floppy and then check. By booting from DOS/Win
floppy or CD, only FAT partition is accessible but
not NTFS?
g) How often do we updated the anti-virus programs,
because there are new viruses coming in each day?
h) Which is the best anti-virus solution for our scenario,
i.e. Novell Netware/DOS/Windows95,98/NT Workstation
4?
Kindly suggest some solutions for the above.
Please
check out the following possible reasons, which could
help you find a solution for the "System Hangs"
on the network:
1. Make sure the "Physical Cable Connections"
and the network cards are functioning properly. If
the network card is not proper there are chances for
the card making unwanted traffic to the network. This
can make network congestion and all the nodes of the
network will be affected.
The cable connectors you use should not be a defective.
If it is defective, the system will not respond for
that particular connection.
2. To find a defective cable connection, you can try
using Networking utilities, like, "HPOV",
which will enable you to detect the right cable connector
(or) any other defective physical connection. HP Open
View network node manager can be used to get the entire
network information like broadcast traffic, direct
traffic and network congestion.
Please check out the following link to find information
about HPOV utility:
http://www.openview.hp.com/products/nnm/index.asp
3. Also, you may face this problem with "AutoProtect"
option enabled, in Norton Antivirus, when the latest
Symantec Files (Norton Antivirus) has not been updated.
Please check out the following link, which contains
a detailed information about the same:
http://service1.symantec.com/SUPPORT/nav.nsf/docid/199871015361
b) Making the files read-only does not prevent the
file from getting infected by virus. This again depends
on the characteristic of the virus.
c) The new system that is connected to the network
can get infected by the virus if you try to access
any information from any other system, and if that
particular system that you are accessing is already
infected by virus. The accessing of data in the network
is done by making the drives (C:\ or any other drive)
sharable. To reduce the chances of spreading the virus
all over the network we advice you to make a particular
folder and make this sharable instead of the hard
disk.
d) To avoid the system from getting infected again
form some backup file, we advice you to install the
latest and the updated version of Antivirus. This
will scan the backup before the files are installed
into the computer. If the files cannot be repaired
we advice you to remove that particular file/files
from the backup.
e) The updates that are available on the Net will
not be infected by any virus. It is always good to
get an updated version of the antivirus from
the Internet so that your computer can be
protected from the latest virus. The updates will
not contain any virus.
f) As far as we know DOS files system which is FAT,
cannot access NTFS partition, which is more, advanced.
However there are third party utility like "NTFSDOS"
which claim to access the NTFS partition from DOS.
NTFSDOS Professional mounts NTFS volumes and gives
them drive letters, so you can run applications and
use files on NTFS volumes transparently. NTFSDOS Professional
is small enough to run from an MS-DOS
boot diskette so you can even access NTFS volumes
on a system where Windows NT/2000 isn't installed
or able to boot.
Please visit the link given below to get information
about NTFS Professional and download the same.
http://www.sysinternals.com/ntfspro.htm
g) AIt is advisable to keep your computer updated
with the latest antivirus every week. Once a new virus
is found the patches for these virus will be released
within no time.
h) AAs far as we know, the Norton Antivirus solution
7.5 is one of the best antivirus for Novell Netware/DOS/Windows95,98/NT
Workstation 4.
Please visit the link given below to get information
about Norton Anti-virus Solution 7.5
http://enterprisesecurity.symantec.com/products/products.cfm?ProductID=22&PID=1659920
You can also use Norton AntiVirus Corporate Edition
7.5 for Windows 9.x, Windows NT 4.0/2000, NetWare
http://enterprisesecurity.symantec.com/products/products.cfm?productID=23&PID=na
NM
All
responses have been provided by
Qsupport Technologies Pvt. Ltd., Bangalore,
a 24x7, e-services company offering online
advice and solutions for any Internet or computing
usage problems. For more information contact netmagindia@vsnl.com
