Environment: RouterOS v6.42.5 (stable) on 2011UiAS-2HnD

I want to use Ether2 as a WAN connection (in a dual WAN application, so Ethers 1&2) and 3 and 4 for some other stuff as well. I can use any of the GigE ports, but want to use 1&2.

The problem I'm having is that the default configuration assigns ether2 as the admin MAC and bridge MAC. I've tried editing the Admin MAC and can't seem to reassign ether2 without losing access to the router.

Webfig was not an option, the instant I touched the bridge config, I lose access.

I've tried writing a script that deletes and rebuilds the bridge by editing the results of an export with appropriate edits, but no luck.

How am I supposed to do this, or can I?

When you change MAC, you are changing fundamental part of any L2 and L3 connection. You will always end up disconnected, so it is impossible to achieve with "safe mode".
Unless you need to keep everything running during the change, I would not worry about it. Connect directly to the device and change the MAC of your bridge to something manual (careful, do not duplicate any existing MAC or you might find yourself with loop detection leading to disconnection). This will cause disconnection, however, if you are connected directly, you can connect straight away to new MAC or existing IP.

Another way (actually maybe without any disconnection) would be to remove one spare port from bridge (for example eth9/10) and leave it hanging alone. No IP, no bridge... Then it works almost as console port via L2. Once you connect physically, you will find it in neighbour discovery with dedicated unique MAC and your changes to bridge should not affect your connection to already disconnected port.

I figured it out. it was a bit more than I expected. I needed to restore the DHCP server connection to the bridge port, and the local routes as well. They were automatically disabled when the bridge was removed (reasonable, but more sophisticated than I assumed.)

I needed to restore the DHCP server connection to the bridge port, and the local routes as well

But how did you restore those settings if you've lost access to the router? I'm having the exact same problem as you describe.

Serial console. This was an RB2011 which has one.

You both should read vecernik87s post better. No need for serial cable. Unless MAC Winbox has been disabled and as long there is a link, you can always connect to the RB using WinBox and its Neighbors tab (click MAC address).

Your "RTFM" response come across as pretty snarky and initially unhelpful.

Because I read the whole thing in spite of the snark learned the very useful bit that "Unless MAC Winbox has been disabled..." etc.

All *I* did was answer a "how did you" question with how I did it. My response to vecernik87's was that I found that I needed to "restore the DHCP server connection to the bridge port" - incremental information to vecernik87's reply.

You clearly have useful insight and a desire to contribute. Since a lot of us are newbies, it will help more if you offer less RTFM offer useful detail. RTFM without insight into which FM or where in it is not generally of little value.

Oz

Serial console. This was an RB2011 which has one.

Ah, OK, thanks.

I also later discovered the Winbox MAC address connect feature, which is indeed incredibly useful.

This would seem to be a bug that should be reported and fixed, no?

I know that this is a very old thread, but I had the same issue and I wanted to add a quick resolution for anyone trying to do this as well:

In cases where you need to remove ether2 from your bridge, and where ether2 is the first port in the bridge, and this causes the whole router to stop responding, no matter what you do:

Just remove ether3 instead. It removes from the bridge with no issues and you don't need to fart around with the console. I have no idea why this is such a big problem but it literally made me scream and I just gave up. You shouldn't have to go through that. Just remove ether3 and label the ports on your physical router.