I am trying to assign an interface eth0:101 with an IP address of 10.217.y.z. Where y and z is my base address. This is for my Linux class that is due by 12:00PM. My instructor approves of this forum so that's cool. I have tried using the command "ip addr add dev eth0:101 local 10.217.y.z" and it takes it but when I do an ifdown eth0:101 I get the error message "ifdown <device name>" so in other words it is not recognizing the device name. So what can I do to resolve that? What am I doing wrong? I will give credit to anyone who can help me out. I have been at this for hours. I need any help I can get. Thanks guys.

Which flavor of Linux are you using? Red Hat, Debian, CentOS, etc....

If I remember right. You gotta do it in a file, something like this:

/etc/sysconfig/network-scripts/ifcfg-eth0:101

I am using Red Hat Enterprise Linux. We are not supposed to create an interface configuration file for this interface.

ifconfig eth0:101 down
Don't use ifdown for virtual interface
Note: If you don't use ongte suggestion, you will have problem when linux box is rebooted. Your command only active at runtime.

I have never really played with Red Hat systems but I have never seen eth0:101 on ANY Linux based systems. I have seen the command of 'ifdown eth0' or even '/sbin/ifdown eth0'. The ifdown may not be in your user's PATH or might not have the rights to execute the ifdown command.

I figured it out, it was right there in front of me with lecture notes must have not seen it clearly...lol. But the correct command was "ip addr add dev eth0 label eth0:101 local 10.217.y.z/8" which was the specified network mask/netmask lol. Thanks for all your help though guys i really appreciate it. So I just didn't add a label to it...lol.

I'd like to say though forums are really really helpful in case if I was working in an actual business environment, because this forum has really helped me to expand my knowledge on Linux/Unix Operating Systems. Because I do enjoy this class and learning about a completely different OS than WINDOWS BLAH...lol. Thanks again every1. Like all of my Networking and Systems instructors tell me use google because it can be your best friend as well as forums as an IT Support Technician/Systems Administrator/Network Administrator. YOU GUYS ROCK THANK YOU AGAIN A MILLION TIMES...lol.