difference ifconfig up and ifup

fawrell · 11-13-2009, 04:04 AM

Hey.

Can anyone pls explain me what is the difference between bringing network interfaces up and down with ifup and ifdown and with ifconfig up/down?

And why ifconfig wiped my routing tables after changing netmask address with it? I'm using RHEL 4.

Tnx for answers!

pixellany · 11-13-2009, 06:02 AM

http://man-wiki.net/index.php/8:ifup

Google finds many others....

If I understand correctly, ifup and ifdown affect all interfaces, whereas ifconfig must be told which one.

fawrell · 11-13-2009, 06:49 AM

Quote:

Originally Posted by pixellany

ifup and ifdown affect all interfaces, whereas ifconfig must be told which one.

Definitely not. Easy test:

[root@localhost]# /sbin/ifup
Usage: ifup <device name>

On both you have to specify interface. And both are affecting (shutting down, starting up) only that specified interface.

pixellany · 11-13-2009, 07:00 AM

Sorry--perhsps I misread something in one of the links I found. You now know more than I do.....

My system does not have ifup and ifdown and I never have an issue just using ifconfig.

kanishka.dutta · 12-06-2012, 05:15 AM

Quote:

Originally Posted by fawrell

Definitely not. Easy test:

[root@localhost]# /sbin/ifup
Usage: ifup <device name>

On both you have to specify interface. And both are affecting (shutting down, starting up) only that specified interface.

I would also like to know the difference between ifconfig up and ifup. How do they both behave different internally? Can you please explain?