Create a sub interface with dhcp

custangro · 09-14-2008, 04:36 PM

Hello,

(Using Ubuntu 8.04)

I know I can add a subinterface in /etc/network/interfaces and it will be all fine and dandy...

But I don't want it permenant...

In Solaris I would just need to do this...

Code:

root@home# touch /etc/hostname.eth0:1 && touch /etc/dhcp.eth0:1
root@home# ifconfig eth0:1 plumb
root@home# ifconfig eth0:1 dhcp start

Apperently this simplicity doesn't exist in Linux

(or at least I can't find how to do this in Linux...that's why I'm posting...)

Is there anyway to do the above in Linux? Again...I don't want it permanent....I just want to be able to do it "on the fly" while I'm on the command line...

I've tried searching Google...but it seems that every solution I find permanently adds the interface...which I don't want.

Any help/suggestions/guidance would be greatly apreceated...

Thanks,

-C

Mr. C. · 09-14-2008, 04:40 PM

IP aliasing:
http://www.faqs.org/docs/Linux-mini/IP-Alias.html
http://pachome1.pacific.net.sg/~hari...uxipalias.html

bgeddy · 09-14-2008, 04:45 PM

From the command line :

Code:

ifconfig eth0:1 192.168.1.100 up

to create an aliases interface with the IP 192.168.1.100

Code:

ifconfig eth0:1 down

to remove the interface.

custangro · 09-14-2008, 05:57 PM

Quote:

Originally Posted by bgeddy

From the command line :

Code:

ifconfig eth0:1 192.168.1.100 up

to create an aliases interface with the IP 192.168.1.100

Code:

ifconfig eth0:1 down

to remove the interface.

Yes...that assigns a static ip address...I was wondering if it is possible to have dhcp assign the ip for me?

-C

Mr. C. · 09-14-2008, 06:03 PM

http://209.85.173.104/search?q=cache...lnk&cd=3&gl=us

custangro · 09-14-2008, 06:46 PM

Quote:

Originally Posted by Mr. C.

http://209.85.173.104/search?q=cache...lnk&cd=3&gl=us

Thanks!

Looks like I'm getting closer now....

But I'm getting an error...trying to run dhcpcd...

Code:

root@CH2:/usr/local/bin# dhcpcd  -h CH2-2 eth0:1
Error, eth0:1: ioctl SIOCSIFFLAGS: Cannot assign requested address

I tried it with the switches from the site you linked to...but still no luck :/

Help? Thanks

-C

Mr. C. · 09-17-2008, 12:09 AM

Sorry, I don't know the answer. Perhaps my response here, bumping the thread will freshen its view to other more knowledgeable eyes.

dumdadum · 04-26-2010, 04:15 PM

Quote:

Originally Posted by custangro

Thanks!

Looks like I'm getting closer now....

But I'm getting an error...trying to run dhcpcd...

Code:

root@CH2:/usr/local/bin# dhcpcd  -h CH2-2 eth0:1
Error, eth0:1: ioctl SIOCSIFFLAGS: Cannot assign requested address

I tried it with the switches from the site you linked to...but still no luck :/

Help? Thanks

-C

I get the same error.

The way I set up this slackware machine was with PXE. And it had to fetch the ip adress from my other slackware machine which I had set up with a dhcp server on.

Now is it possible that the rc.inet1 is trying to fetch the adress from a dhcp server that doesnt exist? If so, how can I solve this? I want the ip adress to be assigned by my adsl modem/routeur.

Let me know,
Dumdadum

dumdadum · 04-26-2010, 04:35 PM

Btw, I get this error with Slackware 13.0 using the following command or simply at bootup time:

/etc/rc.d/rc.inet1 restart

Any help?
Dumdadum

dumdadum · 04-26-2010, 05:06 PM

When I do this command:

ifconfig eth0

I get a hardware adress of 00:00:00:00:00:00

Is this normal? Why was it working before? Is the nic card messed up?

Dumdadum