I have read a few ways to do this, but not 100% sure. I need the interfaces reliably associated to the hardware (there are more than one), so the ifcfg-ethn has the mac address in it. I need to match the mac address of an old router that is about to be removed so I need not change any dns related config.
Thanks! jlc
On Sat, Apr 19, 2008 at 3:02 PM, Joseph L. Casale jcasale@activenetwerx.com wrote:
I have read a few ways to do this, but not 100% sure. I need the interfaces reliably associated to the hardware (there are more than one), so the ifcfg-ethn has the mac address in it. I need to match the mac address of an old router that is about to be removed so I need not change any dns related config.
Modify /etc/sysconfig/network-scripts/ifcfg-ethX and remove the HWADDR line if you have one, and add a MACADDR with the mac address you want to use.
Beware, some network cards may protest having the mac address changed, and using both HWADDR and MACADDR can cause issues. See /usr/share/doc/initscripts-*/sysconfig.txt for details.
Modify /etc/sysconfig/network-scripts/ifcfg-ethX and remove the HWADDR line if you have one, and add a MACADDR with the mac address you want to use.
Beware, some network cards may protest having the mac address changed, and using both HWADDR and MACADDR can cause issues. See /usr/share/doc/initscripts-*/sysconfig.txt for details.
Jim, I appreciate the confirmation, that was the method I was going to use. I am only unsure about what *could* happen with the HWADDR in there, can eth{n} now maybe bind to a different nic under some circumstance?
How can I always force the nic in question to use this script?
Thank you! jlc
On Sat, Apr 19, 2008 at 3:53 PM, Joseph L. Casale jcasale@activenetwerx.com wrote:
Modify /etc/sysconfig/network-scripts/ifcfg-ethX and remove the HWADDR line if you have one, and add a MACADDR with the mac address you want to use.
Beware, some network cards may protest having the mac address changed, and using both HWADDR and MACADDR can cause issues. See /usr/share/doc/initscripts-*/sysconfig.txt for details.
Jim, I appreciate the confirmation, that was the method I was going to use. I am only unsure about what *could* happen with the HWADDR in there, can eth{n} now maybe bind to a different nic under some circumstance?
How can I always force the nic in question to use this script?
Thank you! jlc CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Here is an outline of what I do to "lock-down" interfaces -- which relies mainly on using a fairly new feature "udev":
/etc/modprobe.conf: make sure the lines --
alias eth? <driver>
are in the correct order, e.g.:
alias eth0 e1000 alias eth1 e1000 alias eth2 tg3
/etc/udev/rules.d/: create network rules file (if needed) and add lines that associate a given NIC to its eth? interface. Use "udevinfo -a -p /sys/class/net/eth?" to get various features or attributes to find the NIC that you want to call eth<X>. [Note: this seems to change from release to release, so this is a little general.] You might want to put lines like:
Kernel==eth? ID==0000:03:02.0 Name=eth0 Kernel==eth? ID==0000:03:02.1 Name=eth1
or
Kernel==eth? Sys{vendor}==0x8086 Sys{device}==0x032a Name=eth0 Kernel==eth? Sys{vendor}==0x8086 Sys{device}==0x1079 Name=eth1
/etc/sysconfig/network-scripts/ifcfg-eth<X>:
As other have suggested, now put MACADDR= into these files with the desired MAC address that you want the interface to be set to and delete the HWADDR.
Now, reboot, test and repeat as needed:-):-) ...
I hope that helps and is useful ...
-rak-
Note: I just checked a Fedora 8 box and some of the above has changed -- udev is the way to go, but be advised that this feature appears to be evolving and changing -- hopefully for the better!
-
Jim Perrin -
Joseph L. Casale -
Richard Karhuse