Two RB493G, different S/N but same MAC address???!?!?

RouterOS General
1

Hi,

I bought two RB493G. One was installed in a POP few months ago.
Today I installed the 2nd one on another POP (both are connected to the backbone too).

I started to see on log of one of the routers the interface loop detection alarm (mac address duplicate)

While figuring where was the problem I realized both RB493 have the same MAC address for ether1..ether9. And casualty, both ether2 was connected to the backbone there was a MAC address conflict (as both MACs have different IPs)

Finally I changed the connection of one router to another ether port in order to have different MACs on the same LAN.

How is this possible? Any manufacturing issue?

Regards
Antonio

2

You can set and reset the mac addresses freely as you wish.

3

Seems that a backup got restore from one to the other. The bkp brings the mac addresses. You need to reset them per interface.

Sent from my Nexus 4 using Tapatalk

4

That is why you don’t use backup on one routerboard and restore that same backup file to another. It will bring the mac addresses with it.

Instead use export and import to copy configs between devices. That creates a text file that you can check for mac addresses and edit them out.

export and import are CLI commands.

Here is the manual page for more reading.

http://wiki.mikrotik.com/wiki/Manual:Configuration_Management

Good luck,

Tom

BTW You can reset it back to defaults with /system reset-configuration. I think that might reset the mac addresses back to the shipped defaults. If not, you will have to use Netinstall to set it back to defaults.

5

A simple “don’t import MAC addresses” option when restoring backups would help immensely here. The “principle of least astonishment” doesn’t seem to have much of a following at Mikrotik :slight_smile:

6

i learn that like you in a wlan scenario with duplicated mac on accesspoints

i think wiki do not explain that

7

Hi,

yes I have changed the MACs on one of the routers to bypass the issue.

Both routers have the same factory default MACs , the serial numbers are different.

Regards
Antonio