networking from the command line

[Kevin J. Cummings]

On 08/16/2011 05:59 PM, Michael Hennebry wrote:
> How do I turn on networking from the command line?
> When I do a minimal install, Fedora 14 won't turn on networking for me.
> eth0 never gets an IP address.
> Where is the on-switch?
> Nothing I've tried gets the job done.
> In particular, ifconfig eth0 up does not produce an IP address.

What are you doing?  All "ifconfig eth0" will do is print out the
device's current configuration and let you know if it is up or down.

man ifconfig is your friend.

In /etc/sysconfig/network-scripts you will find a bunch of scripts.
The one named:  "ifcfg-eth0"  will contain the parameters to configure
the eth0 interface for you.  If everything is configured statically, the
all you should need to do is issue the "ifup eth0" command.  If it is
more complicated than that, there may be other steps involved.
In particular, pay attention to the stuff Reindl showed you in his
email.  NM_CONTROLLED, ONBOOT, and BOOTPROTO are all important to you.
Set them to the appropriate values for what you need.

>From the command line, you can always use "ifconfig" or "ip" to set up
anything that you already know about the interface, particularly if you
are using static IP addressing.  After everything is configured, a
simple "ifconfig eth0 up" should bring up the interface.
If you use this method, you are responsible for any necessary changes to
your system's routing table.

If you are accepting a DHCP address, then you need to use "dhclient" to
actually invoke the DHCP and get an address from the DHCP server.  IIRC,
dhclient will bring up the interface after it obtains the IP address it
needs.

> In this case, Fedora 14 is a guest on a VirtualBox.
> If I install the rather large graphical desktop,
> networking works after I click on its toolbar icon,

Because NetworkManager is doing the work for you.

> so I expect the issue is not specfic to VirtualBox.
>>From a thread I started earlier,
> one might get the opposite impression.

-- 
Kevin J. Cummings
kjchome at verizon.net
cummings at kjchome.homeip.net
cummings at kjc386.framingham.ma.us
Registered Linux User #1232 (http://counter.li.org)