how to change ip address without a reboot?

baritono · #1 9th October 2007, 03:04 PM

I'm currently using a Fedora 7 on a Dell laptop. And I need to switch the ip address of my ethernet card between two alternative ones.
Each time I change the ip address through System > Management > Networking, I am promptted that I need to restart my computer or networking manually, but
su -c "/etc/init.d/network restart"
does not work sometimes, and I don't know what to do other than a reboot in this case. So I am wandering if there is a better way to do this.
Thanks in advance!

William Haller · #2 9th October 2007, 03:34 PM

Restarting the network will take care of things as far as the kernel is concerned. There is no guarantee, however, that any program that is running and uses networking hasn't already read the information they needed when they started running and will not continue to use that information under the assumption that it hasn't changed. Restarting the offending applications would enable them to begin using the new IP information.

Changing the IP address (if a server) or the gateway IP address or subnet information for most networked applications may require a reboot to absolutely ensure that all applications will correctly use the new information.

ppesci · #3 9th October 2007, 03:46 PM

The command:

Quote:

su -c "/etc/init.d/network restart"

must to work fine. If you have statics networks addresses to exchange, you can use the command ifconfig. Example:

Quote:

ifconfig eth0 down

shutdown the interface eth0

Quote:

ifconfig eth0 192.168.1.1 netmask 255.255.255.0

Assign the network adress and mask to eth0 interface

Quote:

ifconfig eth0 up

Activate the eth0 interface.

Consult the ifconfig command using "man ifconfig"
But remember, the command you used must to work fine.

HTH

baritono · #4 9th October 2007, 04:59 PM

Thanks for your answers.
I really think
su -c "/etc/init.d/network restart"
should always work, but seems that as soon as eth0 is brought up again, NetworkManager tries to apply the cached (old) ip configuration to eth0.
I killed NetworkManager and NetworkManagerDispatcher deamons, tried the above command again, every thing works just fine.

ppesci · #5 9th October 2007, 05:09 PM

Nice you solved it. Think in a faster way to switch ip address. May be ifconfig will be useful for that.

BTW: Welcome to this forum