Makes me wonder if there is a serious problem with the v2 firmware, obviously it somehow self changed its MAC address, which theoretically shouldn't be able to happen. I don't know a lot about how MAC chips work, but assume the address is stored in some kind of EEPROM or similar memory, and programmed by the manufacturer of the devices. One would think this memory would not be accessible to be reprogrammed at all by the firmware, as it should never be changed...
M1XEP MAC Address changed
- Thread starter whodah
- Start date
In most ethernet controller chips, the MAC address is pre-programmed into each chip at manufacturing time. Every chip gets a unique MAC address. In some chips, there is no way to alter the MAC address. But there are some manufacturers that designed their chips to store the MAC address in a flash memory location, which means it is possible to overwrite it if proper procedures aren't followed to preserve it. Typically, there is a lock register which must first be loaded with a key before the MAC address can be re-written. This prevents an errant write to memory from destroying the MAC address.
If the MAC address changed as part of a firmware upgrade, it would surprise me less than if it just changed at random, which seems to be the case with the M1XEP.
That suggests to me that the ethernet controller chip or the flash is defective. I don't think Elk necessarily deserves the blame for that, but rather whoever manufactured the controller chip or flash memory.
[Edit]:
I dug into the M1XEP a bit, and it contains a Digi Connect ME Ethernet module, which consists of an NS7520 System On a Chip, plus DRAM and flash memory. The MAC address is stored in the flash. In theory, it should be possible to restore it back to its original value. Would probably have to download some special code to do this, and then re-flash the Elk firmware back into it.
If the MAC address changed as part of a firmware upgrade, it would surprise me less than if it just changed at random, which seems to be the case with the M1XEP.
That suggests to me that the ethernet controller chip or the flash is defective. I don't think Elk necessarily deserves the blame for that, but rather whoever manufactured the controller chip or flash memory.
[Edit]:
I dug into the M1XEP a bit, and it contains a Digi Connect ME Ethernet module, which consists of an NS7520 System On a Chip, plus DRAM and flash memory. The MAC address is stored in the flash. In theory, it should be possible to restore it back to its original value. Would probably have to download some special code to do this, and then re-flash the Elk firmware back into it.
Interesting. It had to have happened at random, I have not upgraded any firmware on any of my ELK equipment.
I guess I don't care that much what the MAC is as long as it doesn't keep changing, or change to a MAC that another device in my system has. Other than that, it's fine whatever it is.
I guess I don't care that much what the MAC is as long as it doesn't keep changing, or change to a MAC that another device in my system has. Other than that, it's fine whatever it is.
Crap - mine just started doing this too. Except I can't even get to the IP it's assigned to - the MAC address also ends in 97, but no matter what I do (rebooted the damn thing half a dozen times now) I can't get to it. When I use the 'Find' utility in the M1XEP setup on the RP software, sometimes it finds the thing, sometimes it doesn't - when it does, it's always the same IP and the "new" MAC.
Mine did this too yesterday. I disconnected power from it to move it to a UPS backed supply and when it came back up I couldn't find it.
I used the XEP Find to rediscover it, with a static IP set in a 192.168.3.x network (I use 192.16.1.x on my network) and a new MAC. I updated the MAC for the static DHCP mapping in my router and restarted it but it didn't take that address, it stuck to the address it had now picked.
I then used the jumper method as per P18 of the manual, and even though the results that states did not match what I saw, I managed to persuade it to go back to DHCP and then it took my routers suggestion and went back to the old IP. But with a new MAC.
This is not good. I can't have it do this again. I'll monitor it, but this is something I think someone from Elk needs to comment on. Changing MAC is unusual to say the least but mine essentially reconfigured itself so that it was unusable without intervention.
I used the XEP Find to rediscover it, with a static IP set in a 192.168.3.x network (I use 192.16.1.x on my network) and a new MAC. I updated the MAC for the static DHCP mapping in my router and restarted it but it didn't take that address, it stuck to the address it had now picked.
I then used the jumper method as per P18 of the manual, and even though the results that states did not match what I saw, I managed to persuade it to go back to DHCP and then it took my routers suggestion and went back to the old IP. But with a new MAC.
This is not good. I can't have it do this again. I'll monitor it, but this is something I think someone from Elk needs to comment on. Changing MAC is unusual to say the least but mine essentially reconfigured itself so that it was unusable without intervention.
Hrm. So in summation, this post has seen the following user MAC address changes from -> to:
whodah _____________ -> 00:40:9D:BA
B:AD (note the BAD BAD at the end)
standon _____________ -> (something to the effect of) 8B:AD:BAB:AD:BAB:AD (note the BAD BAD at the end)
geogecko ____________:B8 -> _____________:97
jmark _________________ -> _____________:97
grtaylor 00:40:9D:7E:7B:E3 -> 00:40:9D:43:35:97
I can grab my original MAC off the sticker on my M1XEP, if any of the previous posters wants to supply more info, we can keep a running tally of sorts. See if there is a pattern or something.
whodah _____________ -> 00:40:9D:BA
B:AD (note the BAD BAD at the end)standon _____________ -> (something to the effect of) 8B:AD:BA
B:AD:BAB:AD (note the BAD BAD at the end)geogecko ____________:B8 -> _____________:97
jmark _________________ -> _____________:97
grtaylor 00:40:9D:7E:7B:E3 -> 00:40:9D:43:35:97
I can grab my original MAC off the sticker on my M1XEP, if any of the previous posters wants to supply more info, we can keep a running tally of sorts. See if there is a pattern or something.
I got a detailed reply from Elk. I;m happy with this, I'm leaving mine as-is.
From Elk:
The MAC address is stored in FLASH memory which is considered non-volatile, but FLASH can be overwritten due to some spurious action of the microprocessor. This can be caused by power transients, brief power dips, or complete loss of power when the microprocessor is writing something to FLASH. Very rare instances of this have been known to occur. In the rare instance, the M1XEP’s microprocessor will detect that one or more areas of FLASH may contain invalid data and, in an effort to correct that, restore some default settings. Depending on the version of the M1XEP firmware and the code libraries it uses, it may resort to a MAC address of either 00:40:9D-BAB:AD or 00:40:9D-43:35:97 which lets you know there was a problem. It will not produce a random MAC address. What should you do if this occurs? If there is only one M1XEP on the network, nothing. It will continue to work with the new MAC address. The only thing is, it’s MAC address won’t match the printed label. If there are multiple M1XEPs on the same network, there is the potential that two or more may resort to the same MAC address. This is not desirable, and in that case, Elk Products can restore the original MAC address if the unit is returned.
From Elk:
The MAC address is stored in FLASH memory which is considered non-volatile, but FLASH can be overwritten due to some spurious action of the microprocessor. This can be caused by power transients, brief power dips, or complete loss of power when the microprocessor is writing something to FLASH. Very rare instances of this have been known to occur. In the rare instance, the M1XEP’s microprocessor will detect that one or more areas of FLASH may contain invalid data and, in an effort to correct that, restore some default settings. Depending on the version of the M1XEP firmware and the code libraries it uses, it may resort to a MAC address of either 00:40:9D-BA
B:AD or 00:40:9D-43:35:97 which lets you know there was a problem. It will not produce a random MAC address. What should you do if this occurs? If there is only one M1XEP on the network, nothing. It will continue to work with the new MAC address. The only thing is, it’s MAC address won’t match the printed label. If there are multiple M1XEPs on the same network, there is the potential that two or more may resort to the same MAC address. This is not desirable, and in that case, Elk Products can restore the original MAC address if the unit is returned.whodah said:Hrm. So in summation, this post has seen the following user MAC address changes from -> to:
whodah _____________ -> 00:40:9D:BA
standon _____________ -> (something to the effect of) 8B:AD:BA
geogecko ____________:B8 -> _____________:97
jmark _________________ -> _____________:97
grtaylor 00:40:9D:7E:7B:E3 -> 00:40:9D:43:35:97
I can grab my original MAC off the sticker on my M1XEP, if any of the previous posters wants to supply more info, we can keep a running tally of sorts. See if there is a pattern or something.
Mine after this happened is EXACTLY the same as grtaylors; 00:40:9D:43:35:97. So that seems to match what Elk are saying.
Too lazy to walk upstairs to check the MAC on the board, but mine is currently now: 00:40:9d:43:35:97, which appears to be one of the default ones to fall back on. Interesting situation. Shouldn't be happening, I don't think, but I guess it won't effect me, as long as it doesn't change to the other MAC address (the BAD one).
I do think that mine did happen during a power failure, if I remember correctly. I had to also bring it out of the static IP address mode too.
Back about 2 months ago, I also had a weird thing where it was hammering the outbound internet for some reason, trying to ping some random IP every 5 seconds... I rebooted it, and haven't seen that since.
I do think that mine did happen during a power failure, if I remember correctly. I had to also bring it out of the static IP address mode too.
Back about 2 months ago, I also had a weird thing where it was hammering the outbound internet for some reason, trying to ping some random IP every 5 seconds... I rebooted it, and haven't seen that since.