Tag Archives: servers

Centos Network Configuration – on a Barebones from Command Line

Centos LogoCentos Network Configuration – is very simple on a full installation. However, I downloaded the Centos’ “Minimal Install” cd and used yum to install various packages I needed.

The simple way to do it if you have a standard installation is to use the Network Administration
Tool (system-config-network), which is a graphical interface to edit the configuration files. Since I haven’t installed this tool, I needed to edit the files manually.

How to Configure Network in Centos from Command Line:

A quick way to see if your interface works and if you can ping internal resources.
ifconfig eth0 192.168.0.2 netmask 255.255.255.0
Use your IP addresses.
Note that this is not persistent, at the first reboot, ot first network services restart this will be lost.

For a DHCP address assignment use:
ifdown eth0
dhclient eth0

To get a persistent centos network configuration use the following procedure:

Edit the network configuration file

vi /etc/sysconfig/network-scripts/ifcfg-eth0
Edit the configuration file so it contains your IP address configuration as follows:
DEVICE="eth0"
BOOTPROTO=none
HWADDR="00:00:00:00:00:00"
NM_CONTROLLED="yes"
ONBOOT="yes"
GATEWAY=192.168.0.1
NETMASK=255.255.255.0
IPADDR=192.168.0.2
PEERDNS=no
USERCTL=no

This configures your interface with the IP 192.168.0.2 and the netmask 255.255.255.0.
For more info about Centos’ network configuration look here: .

Set up Name Resolution

Name resolution configuration, is more consistent across various Linux distributions. Most of the Linux distros will have the configuration file at /etc/resolv.conf.
Edit this file and change according to your network:
vi /etc/resolv.conf
Modify the file so it contains pointers to your DNS servers like this:
nameserver 192.168.0.254
nameserver 192.168.0.253

Why Choose Commercial WordPress Hosting

Wordpress logo

Whether you are a seasoned blogger or a beginner one of the best options for your blog is WordPress. WordPress is very popular because of its great flexibility, capacity to adapt to an ever-changing Internet environment, great features, and effortless administration. WordPress was voted many times the best Content Management system in a competition with other renowned CMS.

As a beginner you can start with a free solution, and the WordPress community offers a great platform on their servers, free. On WordPress.com anyone can have their own blog and share their posts on a variety of topics, and interact with other bloggers. This is one of the most popular ways to start your blog. However, advanced bloggers, journalists or commercial blogs need more complex options.

Why Do You Need a Hosted WordPress?

Popular blogs, or business related blogs, need to accommodate larger numbers of visitors without any traffic limitations.
Here are just a few reasons why any rapidly expanding site should consider WordPress hosting.

The free WordPress platform will only give you a limited number of functions and plugins.
Other technical aspects of your blog are not accessible with a free solution. Some of these include: php.ini and .htaccess control, multiple databases, for other PHP scripts, the storage is limited, you have a limited choice of plugins, little control over the theme, etc…
One of the great benefits of using a WordPress web host is the customer service and support. We always do things that we can’t fix on the spot no matter how experienced we are. Using the help of a professional support team ensures that the site will be up in the shortest possible time if something bad happens. For an organization or business that operates online, it is critical that their website is up as soon as possible. It is at stake the company’s reputation, and the money lost during the interruption.
Maybe one of the greatest things with a hosted WordPress is the huge range of plug-ins and add-ons available. These plug-ins add features that can vastly improve the appearance and functionality of your site and ultimately your visitors’ experience.

If you are thinking moving your blog to a commercial service, don’t delay it, the costs of a professional WordPress web host are small compared to the advantages.

How to Choose a WordPress Hosting Company?

Ok, you decided you need a hosting company for your WordPress blog. There are a lot of companies on the market. How do you choose your host?
The services look very similar at first sight, and in most of the cases they are. You need to look for the package which is best able to cater for your requirements.
Define your requirements first and then make your list with companies that fit the requirements.
Compare the finalists on your list based on your personal requirements, customer service and support, Up-time, reputation, and price.

Troubleshoot a Slow Computer Network – Only One Computer on the Network is Slow

Only One Computer on the Network is Slow

Client Computer Network Mask Wrongly Configured
Your network is a class C network, (net-mask 255.255.255.0), and your client computer has its IP address configuration on a class B network, (255.255.0.0). Change the network mask of the client to match the network configuration.

Poor network cards
Bad network cards or bad drivers are very often the reason for poor transfer rates. Test the transfer rate with a different network card.
An outdated computer can also slow down your network transfer.

Bad Network Configuration
DNS Configuration
can be the cause a of slow network connections.
Wrong DNS address in the IP configuration can slow your network dramatically. Your DNS client will try to connect to an inexistent or not working DNS server then give up and try your secondary DNS server. This translates in slowdowns and sometimes even DNS resolution errors.
Fix: Ping the DNS address or, even better, use nslookup and connect to both of your DNS servers to check if they work.

The TCP/IP protocol stack corrupted.

Sometimes no matter what you do you can’t fix the network and this is because the TCP/IP becomes corrupted. The only thing that fixes it is a reset. On older Operating Systems, such as Windows 98 and Windows NT, the fix was to uninstall and reinstall the whole TCP/IP suite of protocols.
Fix: issue the following command to reset it: netsh int ip reset c:\resetlog.txt.

More Than One Default Route
Advanced Lan SettingsA very common mistake is to assign more than on default route to the same computer. Do not confuse load balancing with multiple Default Gateways. You are configuring two network cards, and both of them have a default gateway. This configuration will not work. Usually, a Windows computer will warn you that this is not a good idea, but some users will choose to ignore the warning.
This is a typical problem for laptop users, they connect into the Lan environment and leave the wireless connection on. This will create a lot of problems for corporate users and even for home users.
In order for this type of configuration to work, special routing rules and IP configuration is needed. it is easier to turn the wireless of or have an adapter manager that will automatically do that for you based on your rules.
Advanced Tcp/IP Settings
On a Windows XP there is a way to assign priorities to network cards using a graphic interface. from the Network Connections applet in the Control Panel, click on the Advanced menu and choose Advanced Settings.
On the Advanced Settings window arrange the network cards according to the correct priority.
Another way to achieve this is to change the gateway’s metric for each of the network adapters on the computer. To do this, open the TCP/IP properties on each of the network addapters with a default gateway configured, and click on the Advanced button. On the Advanced TCP/IP Settings window, uncheck the Automatic Metric for the Default Gateway, and enter a value according to your network topology. The lower the metric, the higher the preference for a default route.

This article is part of a five posts series regarding Network Troubleshooting.