Tuesday, 4 February 2014

Advantages of using Ubuntu instead of Windows

"Do what you want, but don't restrict for others the freedoms you have received."

I am Ubuntu User from last 6 years, I have very good experience with Ubuntu. I was handy with Windows OS. When i shifted to ubuntu i was facing very few issues and i resolved within a week. After that i am using ubuntu non stop.

I never try again windows and not even feel to use it again. I feel freedom from license software and enjoy the good world of freedom.

Runs very smoothly even on my Atom n450/2GB netbook; Genuine Windows 7 home basic (pre-loaded) is very sluggish, and nearly unusable at times.

Extremely capable and extremely powerful for those who are not command-line phobic. It's powerful anyway, but you can reach new realms of possibilities with the command line.

Pro: Its faster, its free, it has 1000s of free software, easy to customize, a lot of different Ubuntu biased Operating systems to choose from, Ubuntu, Kubuntu, Xubuntu, Lubuntu, Edubuntu.
Cons: Not great for gaming, can run Windows software under "Wine" but some programs might not work, or might have problems. (But Linux has an alternative software).

So i will suggest every one to use the freedom world.

Good Luck.

Friday, 29 June 2012

error: Directory index forbidden by Options directive:

#[root@localhost ]# tail -f /var/log/httpd/error_log
In apache error log I got following error.
[Wed Oct 07 15:59:50 2008] [error] [client] Directory index forbidden by Options directive: /var/www/html/testfolder/
I changed the AllowOverride option but nothing is happend. Then I read the welcome page text
“To prevent this page from ever being used, follow the instructions in the file /etc/httpd/conf.d/welcome.conf.”
I opend the welcome.conf file.
I found following lines in welcome.conf file.
<LocationMatch “^/+$”>
Options -Indexes
ErrorDocument 403 /error/noindex.html

I changed that to as follows:
<LocationMatch “^/+$”>
Options Indexes
ErrorDocument 403 /error/noindex.html

That solve my problem. Some time your selinux will cause the issue so you need to deactivate the selinux.
Some time File permission will also cause the issue.
You can change the file permission using following command, go to that directory and run following command.
#chmod 777 *

Saturday, 16 June 2012

Verifying Which Ports Are Listening centos

1: access your server and type the commands

nmap -sT -O localhost
if nmap is not installed then first installed the nmap utility and then run the command again
yum install nmap

2: cat /etc/services | grep 834
3: netstat -anp | grep 4444
4: lsof -i | grep 834
hope this will help some one. 

CTO www.wdnec.com

Friday, 8 June 2012

Update an old debian: 404 Not Found; Err http://us.archive.ubuntu.com; Failed to fetch

Today I stumbled into a weird problem. My debian server 5 couldn't update anymore. My /etc/apt/sources.list looked like this:
  deb-src http://archive.ubuntu.com/ubuntu/  main restricted universe multiverse
Running apt-get update gave all sorts of problems as it couldn't find repository servers anymore:
  $ sudo apt-get update
  Ign http://us.archive.ubuntu.com  Release.gpg
  Ign http://us.archive.ubuntu.com  Release
  Ign http://us.archive.ubuntu.com /main Packages
  Ign http://us.archive.ubuntu.com /universe Packages
  Ign http://us.archive.ubuntu.com /main Packages
  Ign http://us.archive.ubuntu.com /universe Packages
  Err http://us.archive.ubuntu.com /main Packages
    404 Not Found [IP: 80]
  Err http://us.archive.ubuntu.com jaunty/universe Packages
    404 Not Found [IP: 80]
  W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/main/
    404 Not Found [IP: 80]

  W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/jaunty/universe/Packages
    404 Not Found [IP: 80]

  E: Some index files failed to download, they have been ignored, or old ones used instead.
To upgrade a really old Debian release, we first need to edit our sources.list and change all (xx.)archive.ubuntu.com to old-releases.ubuntu.com.
   $ sudo emacs /etc/apt/sources.list
So your lines should instead of
   deb http://archive.ubuntu.com/ubuntu jaunty main restricted universe
look like
   deb http://old-releases.ubuntu.com/ubuntu main restricted universe
it works the same on other releases.
Now update the repos
   $ sudo apt-get update
Thanks to MatjaĆŸ Kljun for guiding to the solution.

Imran shahmeer

Monday, 4 June 2012

Wired Vs Wireless LAN Pro & Cons.

Computer networks for the home and small business can be built using either wired or wireless technology.
Wired Ethernet has been the traditional choice in homes, but Wi-Fi wireless technologies are gaining ground fast.
Below we compare wired and wireless networking in five key areas:

ease of installation
total cost

About Wired LANs:
Wired LANs use Ethernet cables and network adapters. Although two computers can be directly wired to each other using an Ethernet crossover cable, wired LANs generally also require central devices like hubs, switches, or routers to accommodate more computers.


Ethernet cables must be run from each computer to another computer or to the central device. It can be time-consuming and difficult to run cables under the floor or through walls, especially when computers sit in different rooms. Some newer homes are pre-wired with CAT5 cable, greatly simplifying the cabling process and minimizing unsightly cable runs.
The correct cabling configuration for a wired LAN varies depending on the mix of devices, the type of Internet connection, and whether internal or external modems are used. However, none of these options pose any more difficulty than, for example, wiring a home theater system.

Ethernet cables, hubs and switches are very inexpensive. Some connection sharing software packages, like ICS, are free; some cost a nominal fee. Broadband routers cost more, but these are optional components of a wired LAN, and their higher cost is offset by the benefit of easier installation and built-in security features.

Ethernet cables, hubs and switches are extremely reliable, mainly because manufacturers have been continually improving Ethernet technology over several decades. Loose cables likely remain the single most common and annoying source of failure in a wired network. When installing a wired LAN or moving any of the components later, be sure to carefully check the cable connections.

Wired LANs offer superior performance. Traditional Ethernet connections offer only 10 Mbps bandwidth, but 100 Mbps Fast Ethernet technology costs little more and is readily available. Although 100 Mbps represents a theoretical maximum performance never really achieved in practice, Fast Ethernet should be sufficient for home file sharing, gaming, and high-speed Internet access for many years into the future.


For any wired LAN connected to the Internet, firewalls are the primary security consideration. Wired Ethernet hubs and switches do not support firewalls. However, firewall software products like ZoneAlarm can be installed on the computers themselves. Broadband routers offer equivalent firewall capability built into the device, configurable through its own software.

Wireless LANs

Popular WLAN technologies all follow one of the three main Wi-Fi communication standards. The benefits of wireless networking depend on the standard employed:


Wi-Fi networks can be configured in two different ways:
"Ad hoc" mode allows wireless devices to communicate in peer-to-peer mode with each other.
"Infrastructure" mode allows wireless devices to communicate with a central node that in turn can communicate with wired nodes on that LAN.
Most LANs require infrastructure mode to access the Internet, a local printer, or other wired services, whereas ad hoc mode supports only basic file sharing between wireless devices.

Both Wi-Fi modes require wireless network adapters, sometimes called WLAN cards. Infrastructure mode WLANs additionally require a central device called the access point. The access point must be installed in a central location where wireless radio signals can reach it with minimal interference. Although Wi-Fi signals typically reach 100 feet (30 m) or more, obstructions like walls can greatly reduce their range.


Wireless gear costs somewhat more than the equivalent wired Ethernet products. At full retail prices, wireless adapters and access points may cost three or four times as much as Ethernet cable adapters and hubs/switches, respectively. 802.11b products have dropped in price considerably with the release of 802.11g, and obviously, bargain sales can be found if shoppers are persistent.


Wireless LANs suffer a few more reliability problems than wired LANs, though perhaps not enough to be a significant concern. 802.11b and 802.11g wireless signals are subject to interference from other home applicances including microwave ovens, cordless telephones, and garage door openers. With careful installation, the likelihood of interference can be minimized.


Wireless LANs using 802.11b support a maximum theoretical bandwidth of 11 Mbps, roughly the same as that of old, traditional Ethernet. 802.11a and 802.11g WLANs support 54 Mbps, that is approximately one-half the bandwidth of Fast Ethernet. Furthermore, Wi-Fi performance is distance sensitive, meaning that maximum performance will degrade on computers farther away from the access point or other communication endpoint. As more wireless devices utilize the WLAN more heavily, performance degrades even further.
Overall, the performance of 802.11a and 802.11g is sufficient for home Internet connection sharing and file sharing, but generally not sufficient for home LAN gaming.


In theory, wireless LANs are less secure than wired LANs, because wireless communication signals travel through the air and can easily be intercepted.
WLANs protect their data through the Wired Equivalent Privacy (WEP) encryption standard, that makes wireless communications reasonably as safe as wired ones in homes.
No computer network is completely secure and homeowners should research this topic to ensure they are aware of and comfortable with the risks. Important security considerations for homeowners tend to not be related to whether the network is wired or wireless but rather ensuring:

the home's Internet firewall is properly configured
the family is familiar with the danger of Internet "spoof emails" and how to recognize them
the family is familiar with the concept of "spyware" and how to avoid it.
babysitters, housekeepers and other visitors do not have unwanted access to the network

Thanks & Regards:
Imran Shahmeer
skype : shahmeer07