Posts Tagged ‘terminal’

When you type an incorrect command in the CISCO IOS terminal/Cisco Packet Tracer you may come across such an issue as show below:

Sample Translating domain server (255.255.255.255) output

To resolve this, use command “no ip domain-lookup” as shown below:

Router>enable

Router#configure terminal

Router(config)#no ip domain-lookup

Router(config)#exit

Finally, if you need to save the changes permanently, you can use the “write” command as shown below:

Router#write

Hope this helps! Feel feel to leave a comment if you have any queries or want to reach out to me. You can also Follow/Subscribe to my blog to get future blog posts! Happy Networking! 🙂

[ Source: Cisco ]

Regards,
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This is a guide on configuring network in CentOS 6.x in Virtual Box with screenshots (using terminal).

[UPDATE: This guide can also be used to configure network on CentOS 6.5]

So, here I have used CentOS 6.3 minimal and will be discussing on configuring the Virtual Box and CentOS for network access. If you need help installing CentOS minimal in the Virtual Box, you can find the instructions in my earlier post here.

Requirements:

  1. Virtual Box
  2. CentOS 6.3 or 6.5 (I have tested this on CentOS 6.3 and CentOS 6.5, you can use it on other 6.x versions too)

Step 1: Configure Virtual Box Network Settings:

There are different modes or ways you can configure your Virtual box network settings.

  1. Not Attached
  2. NAT
  3. Bridged Adapter
  4. Internal Network
  5. Host-Only Adapter
  6. Generic Driver

You can find more details about the different modes here.

I will be using the Bridged Adapter mode for this guide. It is faster as it treat the VM as an individual host within the network.

Open Virtual Box and right click on  your CentOS VM, and click on “Settings“.

vbox settings

Now, go to the tab Network and change the “Attached to” field to “Bridged Adapter”. Then choose the “Name” to your network interface. For example, I have a dell wireless adapter, so I choose the Name as “Dell Wireless” from the drop down menu. And finally check the field “Cable Connected.  Finally, click on OK when you are done.

network settings

So, you have now configured the Virtual Box. Now, you can start your CentOS VM by selecting you VM and clicking on “Start”.

start vm

Step 2: Configure CentOS network settings:

You can configure your network either by using Dynamic IP addressing assigned by your DHCP server or you can manually configure your IP Address statically. You can choose either static or dynamic method and can do so by editing the file /etc/sysconfig/network-scripts/ifcfg-eth0.

Method 1: Dynamic IP 

We can configure the network by using Dynamic IP address which are assigned automatically by the DHCP server. This is the simplest way to configure your network.

NOTE: You will have a line that starts with HWADDR in the your config file, do not change or modify that line.

In your terminal, type the following:

vi /etc/sysconfig/network-scripts/ifcfg-eth0

Now, add/modify the file as follows (DO NOT CHANGE the HWADDR line your config file):

DEVICE=eth0

BOOTPROTO=dhcp

ONBOOT=yes

NM_CONTROLLED=no

HWADDR=08:00:27:08:47:E9

Now, save the file by pressing “ESC” and typing :wq and hit ENTER.

To view your network config file. type the following in the terminal:

cat /etc/sysconfig/network-scripts/ifcfg-eth0

dynamic ip config

Now, you will have to restart your network. You can do so by typing the following in the terminal:

                service network restart

service network restart

To view your IP address, type the following in your terminal:

                ifconfig eth0

You can see your IP Address of the interface eth0 next to the field “inet addr:” as shown below:

ifconfig eth0

Now, if you have internet access, then you can check if you are able to ping any website. And you should be able to get the reply. For example, in your terminal type:

ping extr3metech.wordpress.com

ping results

You can press CTRL+ C to stop the ping command.

So, Hurray! you have successfully setup up your network in your CentOS Virtual Box.

Method 2: Static IP

We can also assign the network information manually by assigning the IP Address, NETMASK , GATEWAY in the network interface config file.

NOTE: You will have a line that starts with HWADDR in your config file, do not change or modify that line.

Step1 : In you terminal, type:

vi  /etc/sysconfig/network-scripts/ifcfg-eth0

Now, edit/merge the file to the following

DEVICE=eth0

BOOTPROTO=static

ONBOOT=yes

NM_CONTROLLED=no

HWADDR=08:00:27:08:47:E9

IPADDR=192.168.1.30

NETMASK=255.255.255.0

GATEWAY=192.168.1.1

Now, press ESC and type :wq and hit ENTER to save and exit the configuration file.

To view the config file. type the following in the terminal:

cat /etc/sysconfig/network-scripts/ifcfg-eth0

view configuration

Step 2: Change Host name: 

To change host name , you have to edit the config file /etc/sysconfig/network. If you want to know to change the host name manually, you can follow the guide I have posted earlier here.

Step 3: Assign DNS Server IP

To manually assign primary and secondary DNS Server IP addresses, in your terminal type: 

vi /etc/resolv.conf

Now, edit this file to the following:

nameserver 8.8.8.8          

nameserver 8.8.4.4

Now, press ESC and type :wq and hit ENTER to save and exit the configuration file.

Now, if you want you can make sure you have entered and saved the correct configuration(It is a good practice to double check 😀 ). To view your dns config file, in your terminal type:

cat  /etc/resolv.conf

/etc/resolv.conf

Step 4: Restart network:

Finally, all you have to do is to restart your network service. To so so, type the following in the terminal:

                service network restart

service network restart

Now, you can check your Current IP configuration, by typing the following in the terminal:

ifconfig eth0

ifconfig eth0

Now, if you have internet access, then you can check if you are able to ping any website. And you should be able to get the reply. For example, In your terminal type:

ping extr3metech.wordpress.com

 ping results

You can press CTRL+ C to stop the ping command.

So, Hurray! you have successfully setup up your network manually in your CentOS Virtual Box.

Hope this guide helped you to configure network in your CentOS Virtual Machine.

If you have any queries or suggestions regarding this guide, feel free to leave a comment and will get back at you. Don’t forget to follow my blog to get future updates! :D

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