Comments on: Red Hat / CentOS: Swap / Change Ethernet Aliases

By: Eric Zhu

Eric Zhu — Sat, 22 Oct 2011 15:36:04 +0000

CentOS 6.0 implement a new system called NetworkManger to manage network . I have to stop this service first to rename network interface with this resolution.

By: anas alaayah

anas alaayah — Thu, 30 Jun 2011 13:00:16 +0000

i’ve followed the steps but when i reboot the system the original mac address back
is there any other solution
thanks all

By: Luis Talora

Luis Talora — Wed, 05 Jan 2011 13:32:35 +0000

Excelent tip! Just what I was looking for. Thanks!

By: Darshak Thakore

Darshak Thakore — Wed, 10 Nov 2010 16:35:45 +0000

Thanks for the tip gndudeus.

Your tip worked for me with CentOS 5.5

With systems that have switched to udev (Fedora, Ubuntu), editing the 70-persistent-net.rules work but for older systems like CentOS 5, this tip is the only way to safely swap eth devices.

By: gndudeus

gndudeus — Sat, 09 Oct 2010 16:09:36 +0000

I encountered this problem today and was able to resolve it using the following steps;

OS: CentOS release 5.2

1) First check hwaddress of your eth0 and eth1 (and any others you may have)-do this by simply using ‘ifconfig’ command and note down the hwaddress.
2) Next enter into your interface config and insert the hwaddr like this vi /etc/sysconfig/network-scripts/ifcfg-eth0. HWADD=mac_address
3) Repeat step 2 for your other network cards.
4) goto /etc/sysconfig/hwconf and under NETWORK, note your driver, e.g device: eth1 driver: r8169. Check this for all your network cards.
5) Now finally goto /etc/modprobe.conf
6) Match your ethernet cards with their correct drivers, e.g. alias eth0 skge
7) Save and reboot.

The above worked perfectly for me. I hope it does help you too.

By: Ploink

Ploink — Thu, 10 Dec 2009 12:49:15 +0000

In Fedora, aliases are assigned by udev.
As Nicholas did, you can simply change the order by editing /etc/udev/rules.d/70-persistent-net.rules and reboot. You do not need to edit/change anything else.

I figured this out when I replaced a network card. I started with eth0 and eth1, then replaced eth1 with a different card and ended up with eth0 and eth2. I deleted the old card from the rules file and changed the new from eth2 to eth1.

I do not recommend to specify the HW address in the ifcfg* files.

By: Nicholas Redgrave

Nicholas Redgrave — Mon, 15 Jun 2009 16:18:47 +0000

I followed the original tip with my Fedora 11 installation but it didn’t work due to a conflict with udev.
I found that I also had to edit “/etc/udev/rules.d/70-persistent-net.rules” and swap the “NAME=eth0″ and “NAME=eth1″ entries over in that file before it worked.

By: Srinivas.Y

Srinivas.Y — Fri, 29 May 2009 09:54:53 +0000

Very good tip….

By: Jeff Schroeder

Jeff Schroeder — Thu, 15 Jan 2009 13:50:12 +0000

For those who don’t know, the Redhat/Fedora ifup/ifdown scripts that read the HWADDR variable are using the ip(8) command to set the names.

You can rename eth5 to eth0 like this:
ip link set down eth5
ip link set eth5 name eth0

Afterwards you’ll need to add an ip and up the interface with the ip(8) or ifconfig(8) commands.
—
Jeff Schroeder
http://www.digitalprognosis.com

By: James

James — Thu, 15 Jan 2009 00:14:57 +0000

Althought the HW address does address the problem in RHEL4/CentOS4 it doesn’t work right in RHEL5/CentOS5 if the box has mixed onboard and PCI Nics or 3 or more Nics. I’ve had a devil of a time with these two and the kernel on RHEL/CentOS getting around this.

In the end my solution (that worked) was to build my own kernel from a newer version of source than RH provides (one from Fedora to be exact). Once I did, I stopped losing NIC’s and having them switch names on me.

What happens in the above scenario is if you do already have the HWADDR line it will refuse to initialize the NIC since the HWADDR (mac) doesn’t match.