Post by Mick FarmerDear GLLUGers,
I'm running Fedora 16 on a Dell Inspiron laptop.
When I boot the machine I get a Ethernet different MAC address!
I can't imagine the laptop doing this (?), so is it a function of
Fedora? If so, how do I stop it?
It is possible for software to change it. If there is a bug in the
ethernet driver or a corrupted eeprom, it might try to behave
differently.
I've seen this myself although that was 5+ years ago on a debian system.
I think it was an issue with the ethernet driver. It knew the
manufacturer value (1st three bytes?) but would randomly set the last
part of the MAC.
Which hardware is the nic card?
I can't remember, but this was specific to that particular chipset when
I checked other servers.
If you wish to fix it to a particular address, you can use the
"ifconfig" to set it to a fixed value in one of the network init
scripts.
I'm afraid my recollection of this is sketchy as this was years back and
once I resolved it I moved on. If somebody from The Positive Internet
Company Ltd is skimming this thread, I documented this issue and the fix
in the server logs for whichever machine I first found it. So an IMAP
search for messages from damion in the serverlogs archive might get the
details back.
My rough recollection of the issue goes like this:
- Box with upgraded OS worked 1st time but failed to join the network on
subsequent boots.
- Raritan NetKVM attached by our suite gnome let me see that rather than
getting an eth0 at boot, it had an eth1 and on a reboot an eth2 etc.
- The incrementing interface name explained why the network scripts at
boot time were failing to assign correct details. I started to track
down the reason after seeing tmp files parsed in /var/<something>
which were written by something in /etc/hotplug.d/ deciding that this
machine was having new/different ethernet cards added between each
boot.
- I eventually realised the MAC was changing! I initially assumed this
was an iffy driver, potentially a less capable OSS version of one with
a binary blob that wasn't sandal-wearing/treehugging/"F"ree enough for
the debian ranters^Wmaintainers, but then found it was doing this MAC
changing mess even on the older dist release, however that
lacked/cared about the hotplug side of stuff and so changing MAC
addresses didn't bother it.
- I think I saw mention in the src/via Google, an inability to correctly determine
the correct address meant it picked the last 3 bytes. I can't
remember if I fixed this with a parameter* passed to the
insmod/modprobe via the correct module aliases configuration mechanism
for this dist, or fudged the hotplug stuff to not increment the
interface even if it did see a new MAC.
*I believe the BIOS was able to correctly see a single correct MAC.
Sorry if this is a bit jumbled/verbose. It was a long time back, but as
I saw people suggest the OP was confusing IP with MAC I felt I should
jump in to say this is a real thing that can happen.
- Damion