Linux.com

Home Linux Community Community Blogs

Community Blogs



Naming Network Interfaces on LInux

Introduction

When the Linux kernel boots, it assigns names (eth0 etc..) to network devices in the order that it finds them. This means that two different versions of the kernel, say 2.4 and 2.6, might find the network interfaces in a diffent order. When this happens you might have to swap all the cables to get your connections to work the way you want. The proper way to do this is to name the interfaces with the nameif command (part of the net-tools).

You can install net-tools by running:

[root@host]# yum install net-tools

MACTAB and NAMEIF

The nameif command can be driven from the command line, if you want to do that, then read it's man page. Another way is to set up a /etc/mactab file to relate the MAC addresses of the network cards to the names you want.

Every NIC interface in the (known) universe has a unique MAC address (Media Access Control address), which is usually expressed as a 12 digit hexadecimal number, colon-dotted in pairs for readability.

You will need to find the MAC addresses of each of your network cards. The easiest way to find these (if you didn't make a note of the MAC label when you installed the card) is to use ifconfig, each interface that is configured will report its MAC address. e.g:

[root@host]# /sbin/ifconfig

eth0 Link encap:Ethernet HWaddr 00:60:97:52:9A:94
inet addr:192.168.1.3 Bcast:192.168.1.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:6043 errors:0 dropped:0 overruns:0 frame:0
TX packets:6039 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:1439604 (1.3 Mb) TX bytes:509857 (497.9 Kb)
Interrupt:10 Base address:0xc800

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:7218 errors:0 dropped:0 overruns:0 frame:0
TX packets:7218 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1085452 (1.0 Mb) TX bytes:1085452 (1.0 Mb)

Take note of the HWaddr, this the NIC's MAC address.

Now you can decide what you would like the NIC to be called, and set up your /etc/mactab, here's mine as an example:

# Begin /etc/mactab
# This file relates MAC addresses to interface names.
# We need this so that we can force the name we want
# even if the kernel finds the interfaces in the
# wrong order.

# eth0 under 2.4, eth1 under 2.6
cyberint 00:60:97:52:9A:94

# eth1 under 2.4, eth0 under 2.6
newint 00:A0:C9:43:8F:77

# End /etc/mactab

If you run nameif (without parameters) now you will probably get an error message, since nameif must be run when the interfaces are down.

[root@host]# nameif
cannot change name of eth0 to beannet: Device or resource busy

so, first take the interface down, then rename it:

[root@host]# ifconfig eth0 down
[root@host]# nameif
[root@host]# ifconfig eth0 up
[root@host]# ifconfig

cyberint Link encap:Ethernet HWaddr 00:60:97:52:9A:94
inet addr:192.168.1.3 Bcast:192.168.1.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:6617 errors:0 dropped:0 overruns:0 frame:0
TX packets:6596 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:1748349 (1.6 Mb) TX bytes:598513 (584.4 Kb)
Interrupt:10 Base address:0xc800

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:9097 errors:0 dropped:0 overruns:0 frame:0
TX packets:9097 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1340480 (1.2 Mb) TX bytes:1340480 (1.2 Mb)

Using ifrename as a newer alternative

nameif has been obsoleted by the ifrename command.

To use the ifrename command first create the /etc/iftab file containing the new interface name and the corresponding MAC address like this:

ifname mac 00:16:3E:3B:B0:52

Bring the interface down and run:

[root@host]# ifrename

Then bring the interface up with the new name specified in the config file:

[root@host]# ifconfig ifname up

 

/etc/sudoers

The sudo command gives users access to otherwise inaccessible commands. The /etc/sudoers file makes use of 3 sets of groups to allow or deny access to commands on the nodes of a network.
 

UbuntuOne -- Selling a sevice? Or themselves?

I recently applied for the UbuntuOne beta program. It seems interesting enough, and sounds like a good idea. But the thing is, why is Canonical trying to hide a storage server and make it seem like it's so much more? What is UbuntuOne you say. Well here's a cap:

 

Sync your files, share your work with others or work remotely, all with your Ubuntu computer.Sync your files, share your work with others or work remotely, all with your Ubuntu computer. 

 

Well, that's not very descriptive now is it. If you go to the plans page, it will give you the option of choosing a 2GB (free) or 10GB (pay) for storage. I'm not saying that this is a bad thing. I'm just trying to say that disguising a FTP storage site as a brand new idea isn't very sportsmanshiplike.

So, am I going to buy an account? Probably. But I still don't like the cover up. Oh ya, and one more thing--Linux Mint had this first, with a storage site and their own FTP for access to it. Just some thoughts for chew.

 

Kubuntu Karmic Alpha 1 Released

Just a quick note letting you all know that Kubuntu Karmic Alpha 1 has been released. If you are looking to contribute to an open source project, there is no better time than now. The Kubuntu team is looking for a few good contributors. We can always use supporters, documentation writers, packagers, developers, translators and more! If you are interested in contributing, I urge you to join #kubuntu-devel on irc.freenode.net.

Note: This is an alpha release, so it is not for the faint of heart, it is for those of you who are a bit crazy and like living dangerously. It is not for production use at all, and if you do use it for production use and get fired, it is not our fault!

 

Copy files recursive with folder hierarchy (rsync method)

rsync --include-from=/tmp/include.txt --exclude-from=/tmp/exclude.txt -aRvm ./src /tmp/dest

include.txt
>>*.pdf

exclude.txt
>>*.*

 

-a, --archive               archive mode; equals -rlptgoD (no -H,-A,-X)

-R, --relative              use relative path names

-m, --prune-empty-dirs      prune empty directory chains from file-list

-v, --verbose               increase verbosity

 

Hello,World!

Hello,everyone!

My name is jiakon.I am a graduate student of Xiamen University.My major is mathematics and I use ubuntu.In addition,I pay much attention on education and organization.

 

Stack Growth Direction.

#include <stdio.h>

void foo(int *);
int main(int argc, char *argv[])
{
int i;
foo(&i);
}
void foo(int *ii)
{
int j;
if ( &j <>
printf("I think the stack grows down.\n");
else if ( &j > ii )
printf("I think the stack grows up.\n");
else
printf("I'm really confused now.\n");
}
 

Good Luck

Good luck!linux.
 

First post!

First post!

 Which isn't that spectacular considering only I can post here. Joined the new linux.com yesterday and I'm certainly looking forward to see how this effort evolves.

Not much of a blogger really, but will occasionally try to share my experiences using linux while pretending to actually know what I'm talking about, as well as sharing some personal thoughts while pretending that somebody else actually knows what I'm talking about.

 

NOOB's adventures in Linux From Scratch

 All I've got to say is if you're from the Windows world, there's no curveballs here. I breezed thru the X windows explanations all except the configuration files area without a hitch.

  Next up .... Getting things done in Linux    

 

Ha.

Well this is neat.
 
Page 129 of 142

Upcoming Linux Foundation Courses

  1. LFD331 Developing Linux Device Drivers
    13 Oct » 17 Oct - Virtual
    Details
  2. LFS425 Linux Performance Tuning Crash Course
    16 Oct » 16 Oct - Düsseldorf, Germany
    Details
  3. LFS220 Linux System Administration
    20 Oct » 23 Oct - Virtual
    Details

View All Upcoming Courses


Who we are ?

The Linux Foundation is a non-profit consortium dedicated to the growth of Linux.

More About the foundation...

Frequent Questions

Join / Linux Training / Board