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MAC address changed itself

 
Coinneach
Occasional Advisor

MAC address changed itself

DL380 G5. NIC1 reset its MAC address to EA:5E:00:0C:EA:5E. Diags (Smart Start 8.15) showed no faults. Firmware was up-to-date according to 8.3. Gremlins? Terrifying space monkeys? Cosmic rays?
10 REPLIES 10
KarloChacon
Honored Contributor

Re: MAC address changed itself

mmm

I've seen weird things on these NICs - NC373i -
but this one is the weirdest

well
try clear NVRAM
and update system rom
Didn't your momma teach you to say thanks!
rick jones
Honored Contributor

Re: MAC address changed itself

When you say "reset" that implies you may have done some sort of previous "set." Did you? What did the MAC address used to be?

Per: http://en.wikipedia.org/wiki/MAC_address

If we take the first octet of the MAC - in this case "EA" and consider the low order nibble (four bits) of "A" that is 1010. That then has the locally administered bit set. So, if something did change the MAC, my guess would be some sort of virtuallization software but that is just a guess.

What sort of software are you running on the system?

there is no rest for the wicked yet the virtuous have no pillows
Coinneach
Occasional Advisor

Re: MAC address changed itself

I mean the MAC address used to be something else, and changed without external intervention to the address in my original post. The box is running RHEL5.
Jimmy Vance
HPE Pro

Re: MAC address changed itself

Did you install an additional NIC? The way the PCI bus is enumerated in Linux can cause device order to change when you add devices to the PCI bus. i.e. What you think is eth0 is actually eth1 and vice versa
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Coinneach
Occasional Advisor

Re: MAC address changed itself

There were no changes to the machine in either hardware or software. The machine crashed and came back up with the different MAC address.
Stefan W
Occasional Advisor

Re: MAC address changed itself

Hi, we had the same issue on a DL360 G5. Suddenly the NIC1 stopped responding and when we looked att the MAC-address it had changed to EA:5E:00:0C:EA:5E. We also noticed that the lights on the NIC flashed simultanously at a four flash intervall. We tried to reboot the server with no luck. But, when we unplugged the electrical cord and reinserted it again the MAC-address went back to normal again. Strange behaviour with no answer.
Tristan De Backer
New Member

Re: MAC address changed itself

I had the same problem today with a ProLiant BL460c G1 with an HP NC373i NIC onboard.

Everything seemed fine, except that the machine had no network connection..at all

-But both network connections were UP in windows
-HP diagnostics (present in the driver) passed all tests.
-Verified the blade switches, connection was "UP".
rebooting did not solve the problem.

Until I remarked the mac address: EA:5E:00:0C:EA:5E

I used the same solution as above, I removed the blade from the enclosure to "hard reset the power", put it back and all went fine afterwards.
MisterX101_1
New Member

Re: MAC address changed itself

Thanks Stefan W,


It seemed to have cleared up for the moment, we will continue to monitor the server for any further issues.


Thanks Again,
Coinneach
Occasional Advisor

Re: MAC address changed itself

Hello Stefan,

Thanks for the tip. I've not had a chance to put it into practice yet, but I've forwarded the info to my coworkers JIC.